Animals {animals} range from protozoa to humans. Animals can have internal or external skeletons.
Single-cell animals {protozoa}| {unicellular animal} (Protista) live in water. Protozoa have no cell walls or can have chitin cell walls. Protozoa can have specialized organelles, such as flagella, cilia, neurofibrils, vacuoles, and eyespots. Protozoa are motile. Protozoa require nutrients.
electrochemical
Protozoa have membrane ion channels and have membrane receptors for light, chemicals, and touch. They maintain electric-voltage differences across cell membranes, because salt and protein concentrations inside cells are different than outside.
Fresh-water protozoa fill vacuoles {contractile vacuole} with excess water and then eject water.
Protozoa {flagellate, protozoa}| (Flagellata) can be oval, have flagella, and have gullets or pseudopods. Euglena are flagellates. Sleeping-sickness protozoa are flagellates. Multicellular plants and marine metazoa evolved from flagellates.
Protozoa {flesh-like protozoa} (Sarcodina) can move by pseudopods. Amoebae eat by surrounding food with two pseudopods to make food vacuoles. Foraminifers secrete chalky shells with pores for pseudopods. Radiolarians secrete silica skeletons.
Protozoa {fresh-water protozoa} can live in fresh water. They fill contractile vacuoles with excess water and then eject water.
Protozoa {spore former} (Sporozoa) can be parasites, form spores {zoospore}, and have no cilia or flagella. Malaria plasmodium forms spores.
Protozoa {stentor} (Infusoria) can have trumpet shapes, for ciliated spiral feeding funnels.
Protozoa {sustorian} can move by cilia {mobile stage, protozoa} when young, attach to substrates by stalks when mature {sessile stage, protozoa}, and have cytoplasm tentacles that hold or pierce prey.
Protozoa {Toxoplasma} (Toxoplasma gondii) can sexually reproduce in cat species. Toxoplasma infect mammals and birds through transmission in feces, food animals, and soil. They form cysts {oocyst} that enter immune dendritic cells when in intestine.
Protozoa {vorticella} (Peritricha) can have cilia, have goblet-shaped bodies, and be retractile.
Protozoa (Ciliata) {ciliate}| can have cilia. Paramecia have oval shape, 2500 cilia, and two contractile vacuoles.
sensation
Paramecia have bilateral receptors, have neurofibril between basal bodies, and can sense if stimulus is from front or rear.
reproduction
Paramecia have one micronucleus for reproduction and one macronucleus for metabolism. Paramecia have eight mating types.
movement
Paramecia swim by spiraling forward. Touch, heat, cold, chemicals, and light change cilia beating and so swimming direction and speed, separately on each side. Paramecia cilia on both sides can go forward or reverse, or one side can go forward while other side does nothing.
Paramecia have holes {anal pore} in cell walls, from which waste leaves.
Paramecia have fixed tubes {gullet}| in cell walls, with vacuoles at base.
Near cell walls, paramecia have small bodies {trachocyst}, which send out filaments to hold prey.
Mating {conjugation, protozoa}| merges cytoplasms and exchanges nuclear material.
Bodies {kappa particle} divide independently and secrete ribonucleoprotein, which kills paramecia without kappa particles.
650 million years ago to 530 million years ago, animal phyla {invertebrate} evolved from protozoa.
types
Invertebrate types include anthozoans, crustaceans, ctenophors, echinoderms, insects, mollusks, stars, and worms. Lower invertebrates include ctenophors, coelenterates, flatworms, gastrotricha, proboscis worms, rotifers, roundworms, sipunculans, and sponges. Higher invertebrates include acorn worms, annelids, arthropods, clictors, lampshells, molluscs, moss animals, onychophora, phoronids, and starfish.
stimuli
Invertebrates sense chemical stimuli. Invertebrates can learn by touch but cannot distinguish shapes. Invertebrates have no joint receptors or proprioceptors, do not know muscle contraction or relaxation degree, and do not know body position. Invertebrates do not feel motivations, such as hunger or thirst.
learning
Invertebrates can learn to manipulate objects.
650 million years ago to 530 million years ago, early invertebrates {lower invertebrate} {marine invertebrate} {marine metazoa} had receptors, nerves, muscles, and glands. Enzyme, transmitter, hormone, messenger, and electrical-signal patterns coordinated behavior.
600 million years ago, body structures {coelom, invertebrate}| had a mesoderm cavity {schizocoelom} or had gut-cavity pouches {enterocoelom}.
Later invertebrates {Bilateria} were bilaterally symmetric [-590000000], with front and back and right and left. Bilateria include protostomes and deuterostomes. Body parts were in pairs, one right and one left {bilateral symmetry, body}, and body had front and back.
The first Bilateria (Urbilateria) included rounded flatworms {roundish flat worm}| (RFW). Chordates split from roundish flatworms 530 million years ago.
530 million years ago to 440 million years ago, later invertebrates {higher invertebrate} had ganglia, separate mouth and anus, muscular guts, developed circulatory systems, and coeloms. Chordates split from roundish flatworms 530 million years ago. For example, arthropods have nervous system on front, and vertebrates have nervous system on back. Both animal groups use same two genes for front and back, but chordate dorsal side is homologous with arthropod ventral side.
During Bilateria development, inner tube can open to outside head first {protostome}, not anus first as in deuterostomes. Protostomes include Trochozoa, Lophotrochozoa, and Ecdysozoa.
Trochozoa protostome worms (Rotifera) {rotifer} {wheel animal} (Monogononta) can be microscopic and aquatic. Rotifers have bladders, nervous systems, and flame cells. Anterior ends have spoked cilia rings.
Rotifera have same cell number {cell constant}. They cannot repair damage or grow after development finishes.
Rotifera have complete digestive tracts, including primitive stomachs {mastox}.
Rotifera have body cavity {pseudocoelom} between body wall and gut wall.
Trochozoa protostome bilaterally-symmetric worms {flatworm} (Platyhelminthes) can have mesoderm, have gastrovascular cavities, have muscular pharynx past mouth, and have reproductive organs.
front and back
Bodies have front and back. They keep back upward.
longitudinal
Bodies are longitudinal, with head, trunk, and tail, requiring body orientation. Head is body part that moves first, holds forward senses, and has mouth.
movement
Flatworms move by cilia, using muscular contraction. Muscles have opposing motions and have rhythms controlled by different cells.
nervous system
Flatworms have one brain ganglion with interconnected ventral nerves. Flatworms fused head ganglia to make brain.
Marine-flatworm brain bimodal neurons can habituate to vibration offset, using vibration-sensitive and tactile-sensitive interneurons. They can habituate to illumination offset, using light-sensitive interneurons.
senses
Flatworms have pigmented eyespot cells and can detect light, smell, and touch.
Flatworms secrete sugary substances {slime}| from gland cells.
Intestinal and blood flatworms have thick outer layers {cuticle, fluke}|.
Planaria excrete through tubes, from intestine to surface pores, which are lined with ciliated cells {flame cell}, to move water and waste out.
Ribbon worms have sections {proglottid} formed by budding behind head.
Male flukes have one slit {schistosome}|, into which smaller female fits.
One-centimeter-long intestinal and blood flatworms {fluke} look like planaria, have suckers, are blood and liver parasites, have no cilia, have thick cuticle, and have generation alternation.
life cycle
Flukes lay eggs, in animal urine or feces, which hatch into larvae {miricadia}. Larvae enter snails and change into different larvae {cercariae}, which can bore into skin, though they have no teeth, and then go to liver. In liver, male and female join {schistosomula} and enter blood to go to intestine and bladder. Adults have covering {tegument} that has few surface proteins but can bind human proteins. Adults can live 30 years.
Common flatworms {planaria}| {planarion} like still fresh water, can be parasites, respire by diffusion, and have tubes with flame cells to move water and waste out. For regeneration, smed-betacatenin-1 gene product indicates head, and Wnt gene product indicates tail.
Ribbon worms {ribbon worm} {tapeworm, animal}| can have suckers, or one ring of hooks, to attach to vertebrate intestines. Tapeworms are ribbon-like, have no mouth, have no digestive system, absorb food, and have proglottids.
Lophotrochozoa protostome worms {Gastrotricha} can be microscopic rotifer-like aquatic worms. Some species have no males but reproduce by parthenogenesis. Gastrotricha are cell constant.
Worms {sipunculan} are Lophotrochozoa.
Lophotrochozoa protostome worms {moss animal}| (Bryozoa) can have coelom and have carbonate or protein shells. Budding makes colonies grow, and sexual reproduction makes new colonies. Mouth and anus are at (Entoprocta) or near (Ectoprocta) lophophore. They have U-shaped digestive systems and have vase or tube shapes.
Moss animals have circular ridges with tentacles {lophophore} at top.
Moss animals form colonies {sea mat}, on seaweed.
Lophotrochozoa protostome worms {proboscis worm} (Nemertea) can be harmless, live in ocean, be 20 centimeters to 2 meters long, have narrow bodies, and have complete digestive tracts. Proboscis worms have circulatory systems, containing red blood cells, separate from digestive systems. They have two nerve ganglia connected by one nerve-fiber ring, with two long nerves down back. They have flame cells.
Proboscis worms have one long hollow muscular tube {proboscis}|, which everts from anterior end to get food.
Lophotrochozoa protostome worms {tube worm} {tubeworm} (Pogonophora) (Vestimentifera) can make tubes in which to live.
Sabellastarte longa tube worms {feather duster worm} have tentacles with small branches, on both central-axis sides.
Protostomes {clictor}| (Amphineura) can live in ocean and eat algae.
Lophotrochozoa protostomes {mollusc}| (Mollusca) {mollusk} can have hard carbonate shells. Molluscs are second largest phylum: oyster, clam, octopus, squid, snail, slug, and giant squid. Land snails are molluscs with lungs. Squid seem to feel pain. Molluscs have ganglia groups, each controlling one activity, in ring around gut. Snails have simple eyes. Squid and octopus have compound eyes. Other organ systems are like those in arthropods.
Molluscs have broad flat appendages {foot, mollusc} for creeping.
Molluscs have sheaths {mantle, mollusc} covering visceral mass and foot.
Pharynx has hard parts {radula}|, to break plants or shells. Oysters and clams have no radula.
Molluscs have body-organ masses {visceral mass}.
Bivalves have tubes {siphon, bivalve}| that send water out.
Eye microvilli can lie parallel, exhibit dichroism {rhabdom}, and detect polarized-light polarization plane.
Molluscs {bivalve}| (Pelecypoda) can have two shells, hinged at one side, no foot, one tube and valve that takes in water, and siphon tubes that send water out. Gills filter flowing water. Mucus carries food to mouth. Bivalves include oysters, clams, mussels, cockles, and scallops. Foot comes out of shell for movement. Clams and mussels burrow. Oysters do not move. Scallops move by clamping shells shut.
Mussels have sticky threads {byssus}.
Large clams {giant clam} {tridacna clam} can burrow.
Molluscs {cephalopod} (Cephalopoda) include squid, cuttlefish, octopus, and nautilus.
evolution
Cephalopods began 500,000,000 years ago.
anatomy
Head and foot combine. Eight tentacles in octopus, or ten tentacles in squid, have suckers. Two beaks are in mouth. Mantle can fill with water and eject water for jet propulsion movement after mantle receives signals from giant axons. Ink sac squirts to confuse enemies.
anatomy: shell
Cephalopods have little or no shell, as in squid and octopus, or chambered shells, as in nautilus. Nautilus secretes gas into chambers, to float.
anatomy: eye
Eyes develop from skin folds. Octopus rapidly learns visual and tactile discriminations by trial-and-error and can learn complex landscape, using same visual cues that people do. Nautilus eyes are pinholes, with statocysts and eye muscles. Other cephalopods have eyes with photoreceptors in microvilli at right angles, to detect plane-polarized light.
anatomy: brain
Statocysts can detect three-dimensional movement. A cephalopod brain region acts like cerebellum. Cephalopods have visual-memory brain structures. They have no myelin.
blood
Hemocyanin copper protein, which has low oxygen-carrying capacity, causes green blood.
Cephalopods {chambered nautilus} {nautilus} can be tropical and have shells. Nautilus has visual pits, which are indentations with pigmented cells and focus light like pinhole cameras.
Flat spiral-shelled, octopus-like sea animals {ammonite}| are extinct.
Molluscs {gastropod} {univalve} {gastropoda} include snail, limpet, abalone, and slug. During development, they twist so anus is above head. They have one heart, one gill, one kidney, one gonad, one valve, and one muscular foot.
Gastropods {abalone} can have large colorful shells.
Tropical gastropods {conch} can have spiral shells.
Small shelled gastropods can stick to tidal rocks {limpet}.
Large gastropods {triton} can have spiral shells.
Marine slugs and marine snails {nudibranch}| have no shells.
Sea snails {cone snail} can make peptide toxin {cone snail venom} {conantokin} that paralyzes fish or molluscs by affecting calcium-ion channels. Cone snails shoot out one tube with poison at end. 500 species have 50,000 different peptides.
Marine gastropods can have no shells {sea slug} {marine slug}.
Marine gastropods {pteropod} {sea snail, mollusc} {marine snail} are small.
Land nudibranchs {slug, mollusc} have no shells.
Nudibranchs {snail, mollusc} can live on land or in water. Land nudibranchs have shells.
Caterpillar-like worms (Onychophora) {velvet worm} are Ecdysozoa protostomes. Nervous, reproductive, and excretory systems are annelid-like. Circulatory and respiratory systems are arthropod-like.
Ecdysozoa protostomes {tardigrade} {water bear} can be 1.5-millimeters, live from oceans to mountains, and survive without water.
Ecdysozoa protostomes {roundworm} {nematode} can be microscopic, live on land and water, have pseudocoelom, have long cylindrical bodies, have cuticle, and have no cilia. Nematode parasites include hookworm, trichina worm, and ascaris worm. Roundworms have different sodium channels {roundworm sodium channel} in neurons than other phyla [Bargmann, 1998] [Niebur and Erdös, 1993]. Caenorhabditis elegans has reward-system dopamine neurons [Cherniak, 1995].
Roundworms {ascaris worm} can be intestinal parasites.
Worm {hookworm, worm} mouth hooks can stick to inner intestine walls.
Roundworms {trichina worm} can be intestinal parasites.
Jellyfish, hydra, sea anemones, and corals {coelenterate}| {cnidaria} are Ecdysozoa protostomes, live in ocean, and have radial symmetry.
digestion
They have mouths with tentacles that push food into mouth. Chemicals digest food in sacs, and then pseudopods from endoderm make food vacuoles.
tissues
Tissues are epithelial, connective, muscular, nervous, and reproductive.
senses
Hydra and jellyfish can sense mechanical, thermal, and chemical stimuli.
nervous system
Coelenterates were first animals to have neurons, synapses, and nerve nets, as well as specialized sense organs, but coelenterates have no organized interneurons or ganglia.
Both neural and non-neural cells transfer electrical signals by electrotonic coupling, with no chemical synapses.
In hydra, mechanical stimulation releases acetylcholine, epinephrine, norepinephrine, serotonin, and histamine transmitters from neurons, which discharge nematocysts.
classes
Classes are watery hydroids or hydra (Hydrozoa), flowery anemones and corals (Anthozoa), and bowl-shaped jellies (Scyphozoa). Corals and anemones are polyploid and stationary. Bases are downward, and tentacles and mouth are upward. Jellyfish are medusoids, swimming with tentacles and mouth downward.
colonies
Portuguese man-o'-wars bud on top of each other to make colonies.
Coelenterates have stinging cells {cnidocyte}, whose tips contain one nematocyst.
Cnidocyte tips contain one coiled stinger filament {nematocyst}, which can have poison, uncoil through cnidarian skin to puncture small animals, and entwine prey before digestion.
Coelenterates have one hollow sac with gelatin matrix {mesoglea} between endoderm and ectoderm.
Bacteria {zooanthellae} live in polyps and make oxygen used to make carbonates.
Anemones {sea anemone} {anemone, coral} {coral} use vertical partitions in hollow sac to make chambers to increase digestive surface, have gullet between mouth and hollow sac, and secrete carbonates. Anemones have one stalk with top stinging-tentacle ring. Corals make reefs. Living parts are on top, and sand and dead algae and coral are below.
Reef coral can look like brain cortex {brain coral} (Meandrina).
Coral colonies can have horny flexible branching axial skeletons {gorgonian} (Gorgonacea). Sea whips are gorgonians with long single stems. Sea fans have fan-shaped or tree-shaped skeletons.
Class Hydrozoaregenerate {hydra}| (order Siphonophora) attach to substrates by epidermal-cell discs at opposite end from mouth, and are one centimeter long. They have asexual budding. In stagnant water, high carbon dioxide causes mating types. Hydra have nerve nets. Nervous system governs tissue patterns and regeneration. Hydra polypeptide also is in bovine and human hypothalamus.
Blue hydra {Portuguese man-o'-war} float and have tentacles.
Scyphozoa {jellyfish}| have tentacles that move body through water and have thick mesoglea. Largest jellyfish is Cyanea, with 30-meter tentacles and four-meter diameter. Jellyfish have a statocyte with granules on hair cells. Marginal ganglia supply jellyfish rhythmic beats.
Jellyfish can have diploid sexual polyps and then have diploid asexual forms {medusa}|.
Jellyfish can have diploid sexual forms {polyp, jellyfish}| and then have diploid asexual medusa.
Sea walnuts and comb jellies {Ctenophora} are Ecdysozoa protostomes and live in ocean. They are similar to coelenterates but have only two tentacles. They have no stinging cells, move by cilia, can regenerate, and balance by a limestone-pebble otolith on a ciliated-nerve bed.
Jellyfish-like ctenophors {comb jelly} (class Tentaculata) (order Lobata) can be radially symmetric, be hermaphroditic, and have eight cilia rows.
Jellyfish-like ctenophors {sea walnut} {sea gooseberry} {Venus' girdle} can be plankton eaters.
Sponges (Porifera) {sponge, animal} are Ecdysozoa protostomes, live in ocean, are slimy, have bad smells, have porous skeletons, and have drab colors. Sponges have no body symmetry.
cells
Sponges have cellular differentiation for reproduction, food gathering, and skeleton production but no special tissues.
association
Sponges are ectomesenchymal-cell associations. Specialized intercellular junctions are within mesenchyme.
pores
Sponges take in water and food through skeleton pores. They force water out other pores. Pore epithelio-muscular cells and oscular sphincters regulate water flow.
Spindle-shaped and neuron-like mesenchymal cells are adjacent to pinacocytes and choanocytes. Large multipolar neuron-like cells are in collar below osculum. The neuron-like cells contain small, granular vesicles and norepinephrine, epinephrine, serotonin, acetylcholinesterase, and monoamine oxidase.
sensation
Sponges have cells that react to stimuli but no cell coordination.
Sponges have cells {collar cell} with flagella to move water in collar, below osculum.
Sponges have cells {amoebocyte} that move through matrix, collect food and water, secrete skeleton, and then become epidermal cells.
Sponges {calcarea} can have calcium-carbonate external skeletons.
Sponges {demospongia} can have spongin-protein external skeletons, to form soft sponges.
Sponges {glass sponge} can have silica external skeletons {hexactinellida}.
Ecdysozoa protostomes {arthropod} (Arthropoda) can have appendages.
segmentation
Species have numbers of body segments. All arthropods have same body plan, with six head segments {head, arthropod}, then middle segments {thorax, arthropod}, and then end segments {abdomen, arthropod}.
appendages
Arthropods have paired jointed appendages, used for swimming, walking, sperm transfer, or mouth parts.
coelom
Arthropods have true coelom, with reproductive organs.
digestion
Digestive system is annelid-like.
excretion
Excreting system can empty into digestive tract.
nervous system
Arthropod nervous systems are annelid-like, but ganglia fuse more in higher arthropods. Arthropods have ganglia groups, each controlling one activity, in ring around gut.
eyes
Compound eyes work like fish-eye lenses and show continuous scenes. Bees can process 300 images per second and can see ultraviolet but not reds.
pigments
Arthropods have hormones for pigmentation and reproduction.
behavior
Arthropods respond by kinesis, immobilization, orientation, or navigation. Arthropods have instincts, initiated by stimuli. Some arthropods have biological clocks. Arthropods can learn to run mazes. Arthropods can measure lengths and angles, for honeycombs and spider webs.
Arthropod circulatory systems have blood cavities {hemocoel} and pumping organs.
Arthropods have outside skeletons {exoskeleton}, with inner chitin layer, middle rigid layer, and outer waxy layer.
Arachnids and horseshoe crabs have head, thorax, and abdomen fused together {chelicerate}.
Crustaceans {crustacean}| (Crustacea) are aquatic and live mostly in ocean. They have one mandible pair, have two maxillae pairs, respire by gills, and molt. They have compound eyes. They have two antenna pairs. Shrimp, crayfish, lobster, and crab have ten legs and can have carapace. Barnacles, water fleas, and krill have six or eight legs. Copilia has two eye lenses, for close vision. Vargula firefleas make intense light.
Crustaceans have eyes {compound eye}| with similar parts.
Crustaceans respire by membranes {gill, crustacean}| in contact with flowing water in association with blood vessels.
Crustaceans have upper and lower jaws {mandible, crustacean}|.
Crustaceans have two cheek-part pairs {maxillae}|.
Small tidal filter feeders {barnacle} have free-swimming larvae. Cirripedia adults have hard shells and attach to rocks.
Trilobites {trilobite} (Trilobita) are extinct, lived at ocean bottom, had three larval periods, had three longitudinal lobes, and were 60% of all animals during Ordovician. They began in Pre-Cambrian and lasted until Permian, 300,000,000 years. They most closely relate to horseshoe crab. Trilobites swam, crawled, and burrowed.
parts
They had head {cephalon}, thorax, and tail {pygidium}, each with side lobes {pleura, trilobite} and central lobe {axis, trilobite}. Cephalon has top central plate {glabella} with side shells {fixed cheek}, making structure {cranidium}. Segments had two arthropod jointed legs, which branched to have gill surface and walking leg. Two antennae were on head.
The most important crustaceans have ten legs {decapoda} {decapod} and can have carapace. They include shrimp, crayfish, lobster, and crab.
Decapoda can have chitin {carapace}| with calcium salts.
Warm fresh-water decapods {crayfish} {crawfish} (Astacus) have claws.
Small long-tail decapods {shrimp, crustacean} (Natantia) have fused head and thorax and segmented abdomen.
Decapods {prawn, crustacean} can be large shrimp.
Baleen whales eat euphausiacea crustaceans {krill}.
Large decapods {lobster, crustacean} have claws. Homaridae have eye stalks {eyestalk}. Homaridae have astaxanthin pigment, which binds to beta-crusta-cyanin protein and is insoluble.
Decapods {spiny lobster} (Palinuridaecan) can have no claws and spiny carapace.
Simple crabs (Merostomata) {crab} have ten legs, have pinching claws, and are chelicerates. Crabs include king crab. Horseshoe-crab eyes can see contrasts and use reflection. Blue-crab males have blue claws. Callinectes sapidus are soft-shell swimming crabs.
Burrowing crabs {fiddler crab} can have males with one large claw and one small claw.
Large crustaceans {horseshoe crab} have hard tails.
Alaska king crab or Japanese king crab {king crab} has claw width up to 3 meters, weighs up to 5 kilograms, and is white inside.
Insects {insect}| (Insecta) have six legs, have up to eleven abdomen segments, have no legs on abdomen, have tracheae, and have simple or compound eyes. Insects can have a small connection between first and second abdomen segments. Insects can have diapause. Insects can form social colonies.
types
Main orders are bees and wasps and ants (Hymenoptera), butterflies (Lepidoptera), and beetles (Coleoptera). Insects are the largest class, with 25 orders, and include cricket, katydid, grasshopper, walking stick or mantis, flea, firefly, ladybug, ant, honeybee, wasp, yellow jacket, hornet, bee, beetle, moth, butterfly, and termite.
Hymenoptera females have one tube {ovipositor}, which can also sting, to insert eggs into hosts.
Crab, bee, and fly have 1000 photoreceptors {ommatidia}, connected to inhibitory retina.
Bees, ants, and termites have associated individuals {colony, arthropod}|, with one female queen.
ants
Bees and ants have male drones. Ants can take slaves. Sterile female worker ants feed soldiers, king or drones, and queen.
bees
Queen bee lays fertilized eggs to make workers, soldiers, and new queen. Workers receive no special food. Soldiers receive royal jelly and then nectar and pollen. New queen receives only royal jelly. Queen lays unfertilized eggs to make king or drones. Queen and king or drones have wings, to fly away to start new colonies. Oldest worker bees get water, pollen, and nectar. Middle-age bees secrete wax, clean up, store food, and guard hive. Young worker bees feed larvae and prepare hexagonal cells for eggs. Bees can recognize colors, except reds. Bees do circling and wagging dances, which show food source angle, direction, distance, and amount.
termites
Termites have one male king. Termites that build mud mounds follow rules about when to add and when to remove mud.
Moths, bees, butterflies, and flies can have large changes between developmental stages {metamorphosis}|. In first metamorphosis stage, egg develops. Then larva hatches from egg, crawls, eats, and looks worm-like. Larva is caterpillar for moths and butterflies, maggot for flies, and grub for bees. Larva molts several times, then makes pupa. Adult breaks pupa cocoon, pumps blood into folded parts, and secretes chitin to harden exoskeleton.
Chilling causes secretion of hormone {prothoracicotropic hormone} that induces prothoracic glands to secrete ecdysone.
Chilling secretes prothoracicotropic hormone, which induces glands {prothoracic gland} to secrete ecdysone.
Prothoracic gland secretes growth and differentiation hormone {ecdysone}, which produces molting fluid.
Metamorphosis hormones {juvenile hormone} can prevent pupa formation and allow molting.
Bee larva {grub}| molts several times.
Fly larva {maggot}| molts several times.
Moth and butterfly larva {caterpillar}| {larva} molts several times.
Last moth and butterfly larval stage is cocoon {pupa}| {chrysalis}, which has molting.
Collapsed folded adults {disc} can develop from special larva egg cells.
Insects can have dormant periods {diapause}| as adults.
Lepidoptera undergo metamorphosis through egg, larva, pupa, and adult {imago}.
Grasshoppers and other insects can have larval stages {molt}|, in which epidermal glands make enzyme that breaks down inside cuticle. Then folded inner cuticle grows. Then water or air intake breaks hard outer cuticle. Then new cuticle hardens, using calcium carbonate.
Cell groups {x organ} and sinus gland have hormone that prevents molting.
x organ has axon-tip bundles {sinus gland} that have hormone that prevents molting.
Flying {flying insect}| can be hovering, flapping, or flipping.
wing
In wing stroke, leading-edge vortex above wing increases lift, because vortex does not detach {delayed stall}. At stroke end, wing rotates to give lift {rotational lift}, like backspin on rising fastballs. At upstroke, wing goes through downstroke wake at orientation that provides lift {wake capture}. Fly hind wings act like gyroscopes to sense body orientation. Flies beat wings at 200 beats per second, under muscle-tension control.
metabolism
Flying is four times more efficient than ground locomotion but uses ten times more energy. Flying muscles have highest metabolic rates. Air has higher viscosity-to-density ratio and so is more viscous than water kinetically.
Flying can involve flapping {flapping} wings up and down.
Flying can involve moving wings in figure eights, with body horizontal {flipping}.
Flying {hovering}| can use horizontal-wing movements and twists with body vertical.
Insects {arachnid}| (Arachnida) can respire by tracheae or book lungs, have simple eyes, have poison claws on head, have eight legs, have no antenna, be carnivores, and be chelicerates. Spider, scorpion, tick, and mite are arachnids.
Arachnids respire by tracheae or by membranes that look like books {book lung}.
Large black spiders {black widow spider} have neurotoxic poison.
Mites {chigger} can be skin infesting.
Arachnids {daddy longlegs} can have long legs and small bodies.
European water mites {diving spider} (Argyoneta aquatica) can make underwater webs.
Spiders {jumping spider} can have 2000 retina receptors but no ganglion cells. Main eye has fovea with 30 cells 10 arc-minutes apart. Main eyes scan objects from one side to another for 1 to 2 seconds. If no recognition, scan repeats. Main eye can rotate 25 degrees for 5 to 15 seconds to learn line orientation. Objects detected are other jumping spiders, small and moving prey, big and coming close predator, or objects to investigate further. Other eyes detect movement and initiate saccades, based on angle between stimulus and body axis. Other eyes take 100 milliseconds to check if saccade succeeds.
Arachnids {mite, arthropod} (Acarina) can be small.
Arachnids {scorpion} can have high curving tails with poisonous sting.
Arachnids {spider, insect} can have eight legs and two body parts and make webs.
Large fuzzy spiders {tarantula} can bite.
Arachnids {tick} can be blood-sucking.
Black widow spider, Australian red-back widow spider, and brown widow spider {widow spider} (Latrodectus) have neurotoxic poisons.
Insects {centipede} (Chilopoda) can have segment leg pairs, be fast carnivores, live on land, have poison claws behind head, respire by trachea, and have flattened bodies.
Centipedes and millipedes can have simple eyes {ocellus}.
Centipedes respire by air tubes {trachea, centipede}.
Caterpillars {inchworm} {measuring worm} can raise middle then stretch out to move.
Small free-swimming fresh-water copepods {water flea} (Cladocera) {daphnid} can have large median eyes, pear-shaped bodies, and long antennae.
Insects {copepod} can have single-channel scanning eyes, like scanning beams in television cameras or electron beams in TV tubes. Copepods are in plankton.
Insects (Coleoptera) {beetle}| can have two wing pairs, two wing covers, and two thin wings. Horny front wings cover back wings, at rest. Mouth is for biting. Stenocara condenses fog on its back and tilts head down to receive water.
Beetles {boll weevil} can live and hatch in cotton balls.
Insects {click beetle} (Elateridae) can click when springing from back to feet.
Shiny green beetles {Japanese beetle} can eat plants.
Beetles {june beetle} can be large, be brown, live in North America, and eat leaves. Larvae feed on grass roots.
Small red beetles {ladybug} can have black spots.
Tenebrio molitor {darkling beetle} {mealworm} {meal worm} larvae are slender, have hard bodies, and eat grains and cereals.
large black beetle {scarab beetle}.
Beetles {stinkbug} can have bad smell.
Smooth oval-body beetles {water beetle} (Dytiscidae) have flattened hind legs for swimming.
Beetles {weevil} (Curculionidae) can eat plants. Snouts curve down.
Insects {ear wig} (Dermaptera) can have rear pincers.
Roaches {roach} (Dictyoptera) include cockroach.
Roaches {cockroach} can have organs {cerci} sensitive to vibration.
louse {cootie} (Blattodea) (Blattaria).
Insects {millipede} (Diplopoda) can have many fused double segments with short legs, be slow, live on land, have cylindrical bodies, be herbivores, and have ocellus.
Insects {fly} (Diptera) can have vision detectors for looming, moving patches, angles, and velocities. In scorpions and flies, membrane lens forms over visual pit to focus light.
Mosquitos {anopheles mosquito} (Culicidae) can transmit malaria.
Flies {blue bottle fly} can be shiny and blue.
Flies {dragon fly} can be large, with four large wings.
Nocturnal flies {firefly} can make light.
Flies {fruitfly} (Drosophila) can have red eyes. Attention affects neurons [Heisenberg and Wolf, 1984] [Tang and Guo, 2001] [van Swinderen and Greenspan, 2003]. Fruitflies can learn by trace or delay conditioning [Tully and Quinn, 1985]. Fruitflies have halteres balancing wings. Larvae eat fruit.
Fireflies have larvae {glowworm}.
Large flies {horsefly} have females that suck blood.
Black flies {housefly} can be small.
firefly {lightning bug}.
Female flies {mosquito} can suck blood.
African flies {tsetse fly} can suck blood and transmit sleeping sickness.
Insects {aphid} (Hemiptera) can be plant-sap suckers.
wingless bloodsucker {bedbug} (Cimicidae).
small winged insect {gnat}.
gnat-like Chironomidae fly or Ceratopogonidae dipteran {midge}.
Insects {scale insect} can make wax scales on plants.
Water boatman and backswimmers {water bug} are large and have piercing and sucking mouth parts.
Fresh-water water bugs {water strider} (Gerridae) (Veliidae) can have long thin legs.
Large insects {cicada} (Homoptera) can make high sounds.
Nymphs {spittlebug} (Cercopidae) can be in bubbly white clumps on plants.
Ants, bees, wasps, and sawflies {Hymenoptera} have two wing pairs, front larger than back. They undergo complete metamorphosis. Females have one ovipositor, which can also sting.
Ants (Formicidae), bees (Apoidea), and wasps (Vespidae) form a suborder {Apocrita}, whose animals have wasp waists.
Female wasps {wasp} can remember their hole states and positions, for two or three days.
large wasp {hornet}.
Midwest and west USA wasp {mud dauber wasp} builds mud nests.
Small wasps {yellow jacket} can be yellow and black.
Insects {ant, insect} (Formicidae) can be wingless and live in colonies. Saharan desert ant (Cataglyphis fortis) tells direction by light polarization and tells distance by counting number of steps and adjusting for weight. Ants take dead ants out of the nest {necrophoresis}. Dolichodial and iridomyrmecin decrease after death. Other ants can detect ant dolichodial and iridomyrmecin and so do not take ants out of the nest.
Small red ants {Amazon ant} can take slaves.
Ants {army ant} can travel together and attack insects.
Red ants {red ant} can be medium size.
Sterile females {soldier ant} can have heavy jaws and armor.
sterile females {worker ant}.
Insects {bee} can beat wings at 200 beats per second, under muscle-tension control. Bees can calculate orientation over ground by angle Sun makes with horizon at highest point {azimuth system}, which varies over year.
Bees and ants have males {drone, arthropod}|.
Bombus bees {bumblebee} loudly vibrate wings and thorax to shake pollen from flower anthers {buzz pollination}. They push pollen along body into leg pollen holders.
Bees {honeybee} can make honey in colonies in hives. Honeybees do not vibrate wings or body. Colonies are dying at higher percentage now {colony collapse disorder}.
Social insects {termite} (Isoptera) can eat wood.
Insects {Lepidoptera} can have two wing pairs covered with scales. Mouth is for sucking. They undergo metamorphosis through egg, caterpillar, chrysalis, and adult. Lepidoptera include butterflies, moths, and skippers.
Lepidoptera {moth, insect} can hold wings flat while resting and fly at night. Moths have feathery feelers, live on land, have two antennae, and have two wing pairs raised by vertical muscle contraction pulling tergum down and lowered by longitudinal muscle contraction at 8 to 75 beats per second, under nerve control.
Large light-green American moths {luna moth} can have hind wings with tails and forewings with yellow crescents.
Moths {noctuid moth} can be pale and medium-size.
Noctuid-moth larvae {army worm} swarm and eat grass and grain.
Lepidoptera {butterfly} can hold wings straight up while resting and fly only by day. Butterflies have smooth feelers with end knobs, live on land, and have two antennae. Bicyclus-anyana adults have color if born in rainy season but are gray if born in dry season.
thorax upper-surface plate {tergum}.
Tropical butterflies {swallowtail} (Papilionidae) can have three leg pairs and tailed wings.
Insects {mantis} (Mantodea) can have big forelimbs, like grasshoppers.
Insects {cricket} (Orthoptera) can leap and make high sounds.
Insects {grasshopper} can leap, have long hind legs, and chirp.
Green insects can make shrill sounds {katydid}.
cicada or swarming grasshopper {locust, arthropod}.
Insects {louse} (Pediculidae) (Phthiraptera) can be small and wingless.
louse parasitic insect eggs or young {nit}.
Insects {flea} (Siphonaptera) can be small, wingless, and blood sucking.
Caribbean fleas {chigoe} can be skin infesting.
Bristletail (Zygentoma) and firebrat (Thysanura) {silverfish} are wingless and silver and eat book and cloth starch.
Ecdysozoa protostomes {annelid}| are higher worms.
skin
Epidermis secretes mucus and cuticle, to prevent water loss.
movement
Circular and longitudinal muscles cause movement by stretching and contracting.
digestion
Annelids have schizocoelom. Annelids have mouth, pharynx, esophagus, crop, gizzard, and straight intestine.
blood
The two main blood vessels connect by pairs of muscular tubes acting like hearts. Vessels have capillaries.
nervous system
Head has stimulating ganglion and inhibiting ganglion. Segments have one small ganglion each. Reflex arcs run from sense cells to muscle sets. Neurons have few dendrites, no myelination, few Schwann cells, no oligodendroglia, no astrocytes, no microglia, no nerve tracts, no inhibitory surrounds in receptor fields, no feedback circuits in receptor fields, and no amacrine cells in receptor fields. Neurons have basic neurotransmitters, ion channels, excitability, synaptic potentials, pacemakers, and rhythmic voltage patterns, with frequency twice as high as in vertebrates.
senses
Annelids can have eyes and antenna. Membranes cover visual pits to protect photoreceptor cells.
pigment
Earthworms have pigmented skin cells.
pain
Worms feel no pain.
Segments have two strong short hairs {bristle, hair}| on epidermis.
Annelids have 100 similar parts {segment, worm} {segmentation, worm}|, with pairs separated by septa.
Walls {septum, segments} separate annelid segment pairs.
In septa, blood vessels surround ciliated-funnel pairs {nephridium}. Tubes lead from nephridia to surface to carry away wastes.
Tubes from nephridia have enlargements {bladder, annelid}| in centers.
Annelid stomachs have one storage part {crop, stomach}| and one gizzard.
Annelid stomachs have one crop and one digesting part {gizzard}|.
Testes and ovaries are in same animal {hermaphrodite}| and have tubes leading to surface. Two worms press together and deposit sperm in each other.
Worms form coverings {cocoon}| from bottom to head, in which they first deposit eggs and then sperm.
Annelids {earthworm} {oligochaeta} {night crawler} {worm, animal} can have few bristles and live in soil and fresh water.
Annelids {leech} (Hirudinia) can have suckers at ends to draw blood from vertebrates, use anticoagulant, and have no bristles.
Marine annelids {marine annelid} {archiannelida} can be non-segmented marine worms without bristles.
Ocean annelids {ocean annelid} {polychaeta} {polychaetes} can have many bristles and separate sexes, which release gametes into water by seasonal, lunar, and diurnal cycles.
During Bilateria development, inner tube can open to outside anus first {deuterostome}, not head first as in protostomes.
Deuterostome worms {lampshell} (Brachiopoda) can live in ocean and have coelom. Lampshells have a top carbonate shell and a bottom carbonate shell. Lampshells are oldest genus with living members. Brachiopoda and Phoronida share common ancestor, from which Enchinodermata ancestors split.
Deuterostome worms {phoronid} (Phoronida) and Brachiopoda have a common ancestor, from which Enchinodermata ancestors split.
Starfish, sea star, sea urchin, sea cucumber, serpent star, and sea lily {starfish} {echinoderm} (Enchinodermata) are deuterostomes, live in ocean, have radial symmetry, have central disc, have five to twenty arms, and have mouth on underside. Starfish have no ganglia and no circulatory, respiratory, or excreting system. Brachiopoda and Phoronida share common ancestor, from which Enchinodermata ancestors split. Hemichordata ancestors and Echinodermata and Pterobranchia ancestors split.
Starfish can pump water {water vascular system}, to move and to open prey.
Enchinoderms {sand dollar} (Clypeasteroida) (superorder Gnathostomata) (class Echinoidea) can be flat and circular, have spines, and have five-star patterns. They relate to sea stars, sea urchins, and sea cucumbers.
Enchinoderms {sea cucumber} (Holothuroidea) can have cucumber shapes, flexible bodies, and tentacles.
Enchinoderms {sea urchin} (Echinus) (class Echinoidea) can have shells, long spines, tube feet, and five movable mouth parts.
Enchinoderms {sea star} can have star shape and five or more arms with tube feet.
Euryale, Astrophyton, and Gorgonocephalus {basket star} have slender branched crossed arms.
Worms {acorn worm}| (Enteropneusta) can live at ocean bottom, have proboscis attached to collar at cylindrical body top, and eat organic matter. Hemichordata ancestors and Echinodermata and Pterobranchia ancestors split. Chordata ancestors and Hemichordata ancestors split.
Prechordates {stem chordate} had notochord in both larval and adult stages, allowing muscle attachment, providing long body axis, and affecting reproduction.
germ layers
Prechordate embryos had three cell layers. Endoderm is inner tube, mesoderm is between, and ectoderm is outer tube. Ectoderm becomes senses, nerves, and outer skin. Mesoderm becomes muscles and glands. Endoderm becomes digestive tract.
coelom
Prechordates had tube-shaped body structures, with digestive tube inside main tube.
deuterostome
During development, inner tube opens to outside anus first.
head and tail
Having coelom makes longitudinal bodies, from which head, trunk, and tail can separately evolve. Head holds central ganglia and mouth.
bilateral symmetry
Body parts and appendages have pairs, one right and one left. Body also has front and back. Bilateral symmetry [-590000000] resulted from having coeloms.
segmentation
Prechordates had repeated body structures, allowing different lengths and requiring coordination among body segments. Segments can vary independently.
development stages
Prechordates had streamlined larvae with cilia for swimming in mobile stage. Adult sessile stage did not move. Prechordate ciliated larvae evolved to become stem chordates.
bone
Stem chordates calcified tissue to make bone, allowing better muscle attachment, more shapes, and more textures.
respiration
Stem chordates had external respiration by gills, allowing efficient oxygen uptake and carbon-dioxide removal from blood. Body-side gill slit openings allowed water to flow into mouth and through gills, resulting in better respiration.
nervous system
Prechordates had main head ganglion, with peripheral nerves to tail. Head ganglion provided unified control for all body segments and allowed swimming, burrowing, and defense. Stem chordates had dorsal hollow nerve, so all nerves have same pathway from head to periphery. Cerebrospinal fluid was in dorsal hollow nerve. Nerves were bilateral sense and motor paths. Interneurons coordinated neurons.
hormones
Hormones from glands affect neurons and other tissues.
Chordates {chordate}| (Chordata) are deuterostomes and have bilateral symmetry.
types
Amphioxus is a living chordate, has no jaw, is flat, and is small. Pikaia was an ancient chordate [Bone, 1979].
evolution
Hemichordata ancestors and Echinodermata and Pterobranchia ancestors split. Chordata ancestors and Hemichordata ancestors split. Chordates developed from prechordate larval forms.
notochord
Early chordates had one firm cartilage segmented rod down back along body long axis, allowing increased swimming efficiency by providing places for muscle attachment. Adult notochords allowed reproductive-method changes.
external respiration
Early chordates had paired pharyngeal gill slits. Side openings allowed greater water flow into mouth, over gills, and out body. Blood oxygen uptake and carbon-dioxide removal became more efficient with gills.
filter feeding
Skin calcification made dermal bone that allowed structures for catching small organisms in water flowing into mouth. Filter feeding gathered more food and calcium.
nervous system
Dorsal hollow nerve lay along back under notochord, from periphery to head, and had sense and motor pathways. Cerebrospinal fluid formed in middle.
brain
Head ganglion unified control over all body segments and other ganglia, coordinating sense input and motor output. Brain allowed better swimming, burrowing, and defense and more coordinated behavior. Eye, pineal gland, hypothalamus, and hindbrain began in chordates. Chordates had serotonin neurons, which later evolved to brainstem.
senses
Sense cells detected motions and stationary patterns.
Skin-tissue calcification {dermal bone, chordate} allows structures for filter feeding.
Dermal bone allows structures for catching small organisms in water flowing through mouth {filter feeding}, which gathers more calcium to make bone and allows more energy and larger sizes.
Chordates have flexible straight cartilage {notochord}| down back.
Stem chordates have head as unique body segment, whose ganglion {main ganglion} provides unified control for all body segments and allows swimming, burrowing, and defense.
Stem chordates have a tube of nerves down back {dorsal hollow nerve}, so all nerves have same pathway from head to periphery.
Prechordates have ciliated larvae that swim {mobile stage, prechordate}.
Prechordates have mobile larval stage that has movable hairs {ciliated larvae} and swims.
Prechordate adult stage {sessile stage, prechordate} does not move and evolved little.
Stem chordates have external respiration {gill, chordate}|, allowing efficient oxygen uptake into blood and carbon-dioxide removal from blood.
Body-side openings {gill slit}| allow water to flow into mouth and through gills, for better respiration.
Gills allow blood and water to exchange oxygen and carbon dioxide {external respiration} efficiently.
Embryonic bodies have endoderm alimentary canal within ectoderm tube {coelom, chordate}|, with mesoderm between tubes.
Ectoderm coelom surrounds endoderm tube from mouth to anus {alimentary canal}|, with mesoderm between tubes, allowing better digestion.
Chordates {cephalochordate} (Cephalochordata) can have body segments, be small, be fish-like, strain seawater for food, and have no brain. Adults have chordate characteristics.
540 million years ago, later chordates {prevertebrate} calcified skin {dermal bone, skin} and formed cranium bone around brain, allowing more muscle-attachment sites and better protection. Prevertebrates had structures for filter feeding.
Chordates {tunicate}| {sea squirt} (Urochordata) can live in tropical oceans, be sessile or floating, and have translucent cellulose covers, with hole for incurrent siphon and hole for excurrent siphon. They filter-feed to catch phytoplankton. They can bud. Larvae have chordate characteristics, but adults have gill slits. Vertebrates evolved from tunicate larvae.
Floating tunicates {salp} can have barrel shapes and live in colonies, making tube strings. Salp feces sink to bottom, carrying phytoplankton carbon molecules from carbon dioxide.
Swimming tunicates {larvacean} {apendicularian} (Larvacea) can have oval bodies, movable tails, and notochords. Every few hours, they make 2-centimeter-diameter gelatin mass around body, in which they trap plankton. Mucous mass sinks to bottom, carrying phytoplankton carbon molecules from carbon dioxide. Larvaceans make no buds, only use sexual reproduction, and are mostly hermaphrodites. Sperm release first. Breaking body wall releases eggs and causes death.
Tunicates have translucent cellulose covers {tunic, tunicate}, with hole for incurrent siphon and hole for excurrent siphon.
530 million years ago, chordates {vertebrate} developed cartilage or bone notochords, allowing more muscle attachment.
skeleton
Vertebrates have internal cartilage or bone skeletons, to replace or reinforce notochord. They have backbone segments {vertebra, vertebrate}. They have one cranium. Distinct trunks are between heads and tails.
circulation
Closed circulatory systems use blood vessels.
pharynx
Pharynx separates digestion pathway from respiratory pathway, making both more efficient and independent.
skin
Two-layer skin has epidermis and dermis.
communication
All vertebrates communicate using signs, such as gestures, odors, calls, cries, songs, and dances.
nervous system
Vertebrate brain has hindbrain, midbrain, and forebrain. Hindbrain has ganglia for sleep, wakefulness, and sense information analysis, and cerebellum for coordinating motor behavior. Midbrain has ganglia for sense information analysis. Forebrain has occipital lobe for visual information analysis, temporal lobe for hearing and equilibrium information analysis, parietal lobe for touch and temperature information analysis and motor output, and frontal lobe for smell information analysis.
senses
Eyes develop from brain. Ears are for balance in lower vertebrates and for sound in higher vertebrates.
evolution
Early vertebrate was Sacabambaspis [-450000000].
evolution: superclasses
Superclass is fish (Pisces), with highly vascular gills. Superclass is legged vertebrates (Tetrapoda), with four appendages, including amphibians (Amphibia), reptiles (Reptilia), birds (Aves), and mammals (Mammalia).
Lower vertebrates {fish} (Pisces) have one heart with one vena cava entering auricle, one auricle connecting to ventricle, and one aorta leaving ventricle. Fish have vascular gills. They have scales. Females lay eggs in water that males cover with sperm. Fish have ears. They are streamlined. They move by swishing tail right and left. They steer with fins. Fish include jawless fish (Agnatha), extinct jawed fish (Placodermi), cartilaginous fish (Chondrichthyes), and bony fish (Osteichthyes).
Fish have canals and openings {lateral line} running from head to tail on both sides, to perceive pressure changes and water-flow changes.
Some jawed bony fish had stump fins {lobefin}|, allowing crawling onto shore. Lobefins later became appendages.
Some bony fish make groups {school, fish}|, which concentrate breeding stock, minimize losses to predators, confuse predators, increase food or danger perception, and move together by sight and lateral line.
Fish have sacs {swim bladder}| that can fill with secreted gas for buoyancy.
Fish have gill slits covered by hard flaps {operculum}.
Fish have gill and neck bones {opercular bone, fish}.
Some bony fish had nasal passages {nares}| with internal openings into windpipe inside body, rather than externally to water. Nares allowed more-efficient breathing, moist and filtered air, and alternative air path through mouth, not just nose.
Some jawed bony fish had nasal passages inside to lungs {internal nares}, allowing more efficient breathing.
Agnatha {jawless fish} were first fish.
size
Jawless fish are mostly small but can be up to one meter long.
body
Jawless fish have cylindrical bodies, with no fins and no jaws. Distinct trunk is between head and tail. Head is independent of trunk. Pharynx separates digestion and respiratory pathways.
backbone
Cartilage backbone supports larger size and more speed.
digestion
Jawless fish prey on small organisms by scavenging and parasitism. They have a sucking disc around mouth. Some agnatha are vertebrate parasites. Jawless fish are not filter feeders.
circulation
Heart has one aorta leaving one ventricle and one vena cava entering one auricle.
circulation: blood
Jawless-fish have hemoglobin with one protein sequence.
skin
Outer-skin epidermis layer is protective and smooth. Inner-skin dermis layer contains blood vessels, skin glands, and neurons.
nervous system
Jawless fish have three brain parts: forebrain for smell, midbrain for sight, and hindbrain for hearing. Telencephalon has olfactory bulb. Optic tectum is for sight. Cortex has three cortical layers. Cerebellum associates with hindbrain for sensorimotor coordination. All vertebrates have similar brainstem serotonin-neuron patterns. Spinal cord distributes nerves to body and collects sense signals.
senses
Vestibular system has one or two semicircular canals and helps balance and vision. Frontal eyes, with no eye muscles and no lens, are for pattern detection and make retinoic acid. Jawless fish can detect prey and mates. Parietal eyes can detect sunlight level. Nostrils aided smell.
senses: pain
Jawless fish seem to feel pain.
behavior
Jawless fish can control sucking.
development
Neural crest is at neural-groove edges.
life cycle
Most jawless fish spawn in fresh-water streams, develop into larvae, metamorphose to adults, and swim back to ocean.
Eel-shaped cyclostomes {hagfish} can have round mouth, have eight tentacles, and eat dead fish by boring. Tongue has horny teeth.
Eel-shaped cyclostomes {lamper eel} {lamprey} (Petromyzontidae) has sucking mouths.
Extinct fish {jawed fish}| (Gnasthostomes) lived in ocean and had jaws.
evolution
Gnasthostomes were cartilaginous-fish and bony-fish ancestors.
bone
Tissue calcification makes tissue firmer. Bone allows strong muscle attachments. Bone allows more shapes, because parts can be soft, medium, or hard. Retinoic acid became homeotic-gene regulator, allowing vertebrates to have head bone formation to create cranium to encase and protect brain and allow more muscle-attachment sites for head movement. Neural crest allows new skull bones, jaws, teeth, peripheral nerves, and dentine plates, under homeotic-gene control.
bone: jaw
Head bones evolved to make muscled and bony jaws, which opened larger and allowed grasping, for greater food intake. Bony jaws were possible because vertebrates had evolved heads separate from bodies and had evolved homeotic genes and gene regulators.
blood
By gene duplication, hemoglobin had four protein sequences.
senses
Jawed fish had eye muscles and eye lenses and so better vision. Vestibular system had three semicircular canals.
nervous system
Jawed fish had thalamuses. Cerebellum was larger. Early jawed fish evolved oligodendroglia, which make myelin, which allows faster saltatory conduction and requires less energy to restore ion balance.
Chondrichthyes {cartilaginous fish}| include shark, skate, stingray, and electric ray. Sharks are fast, but others are slow. Cartilaginous fish live in ocean. They have cartilage skeletons. They have paired jaws. They have two fin pairs. They have scaly skin. They have five to seven gill pairs, which send water from mouth out gill slits. They have teeth that are large scales. They have motor maps in optic tecta. They represent sensations in midbrain.
Skates {skate} have wing-like pectoral fins and are flat diamond-shaped bottom feeders.
Rays {ray, fish} have wing-like pectoral fins and are flat and diamond-shaped.
Torpediniformes {electric ray} has electric organs on head sides and stays near bottom.
Tropical rays {manta ray} can be very large, pelagic, and plankton and small-fish eaters.
Rays {sawfish} can have sharp teeth on long flat snouts.
Dasyatidae {stingray} has long tail with one or more spines with poison. Spines are modified dorsal fin rays.
Sharks {shark} are carnivorous and have heterocercal caudal fins, tough skin, and small scales.
Large northern sharks {basking shark} can be plankton eaters and swim slowly at sea surface.
Tropical sharks {hammerhead shark} can be medium-size, be live bearing, and have flat bar-shaped heads with eyes at ends.
Jawed bony fish {teleost}| {bony fish} evolved.
bone
Fins have bony rays with muscles, allowing better control. Later, rays became fingers and toes.
skin
Bony fish have skin scales.
mouth
Bony fish have mouth at front end, allowing larger opening, more shape and size variation, more growth while maintaining streamlined shape, and larger brain, because fish can maintain streamlined shape even if brain grows.
lung
Some bony fish have lungs surrounded by blood vessels, allowing gas exchange from blood to air, to control buoyancy and extract more oxygen.
nervous system
Fish can detect features, intensities, textures, flows, and surfaces.
types
Fish include sea horse, lungfish, bass, trout, perch, flounder, swordfish, angelfish, tropical fish, goldfish, cod, barracuda, smelt, sardine, and anchovy.
dark gray, medium size, southern, long side fins, flat {angelfish} {angel fish}.
large mouth, filament for luring prey {angler fish} {goosefish}.
Toxotidae {archer fish} {archerfish} shoot water from mouth at insects and live in warm water.
Sphyraena {barracuda} have long cylindrical bodies and projecting lower jaws with long strong teeth.
Fish {crucian carp} can use lactic acid to make ethanol and so does not need oxygen.
Tropical fish with large fins {flying fish} (Exocoetidae) can glide after jumping from water.
large, sea-bass shape {grouper} (Epinephelus) (Mycteroperca).
Fish {grunion} can spawn on beaches at full moon in spring, at highest tide.
tropical, medium size {grunt}.
small fish {minnow}.
long, tubular, tropical {pipe fish}. family Syngnathidae.
Fish {porcupinefish} inflates by swallowing water or air when threatened, relates to puffer fish, and has spines.
East Coast, tropical {porgy} {sea bream} {scup} (Pagrus) (Sparidae).
Fish {blowfish} {swellfish} {globefish} {balloonfish} {puffer fish} (Tetraodontidae) (Tetraodontiformes) inflates by swallowing water or air when threatened and has no spines.
Fish {remora} (Echeneidae) sucking disk can attach to sharks.
Fish {seahorse} can be small, swim vertically, have bony plates, and have horse-head shaped heads.
large, broad shovel-shaped snout, freshwater, ancient {sturgeon}.
bottom feeding, no scales, broad head, wide mouth {toadfish}.
Deep ocean fish {viperfish} (Chauliodus macouni) eats crustaceans and small fish. First dorsal fin has photophores to attract prey.
North Atlantic, soft {weakfish} (Cynoscion regalis).
saltwater white fish {whitefish, fish}, except herring.
long thin upper jaw, related to sailfish and spearfish {marlin} (Makaira) (Tetrapturus).
large flat dorsal fin {sailfish}.
large, long bill at snout tip {swordfish, fish}.
Gulf of Mexico, long body, large silver scales, up to 2 meters and 100 kilograms {tarpon}.
Eels {eel, fish} live in fresh water and spawn in Sargasso Sea in North Atlantic Ocean.
large, colored, tropical reef {moray eel}.
long body, pointed tail {wolffish} {wolf eel}.
flatfish {flounder, fish}.
flatfish {halibut, fish}.
flatfish {plaice, fish}.
flatfish {pompano, fish}.
small flatfish, Pacific coast {sand dab}.
flatfish {sole, fish}.
large European flatfish {turbot}.
small, silver {anchovy, fish} (Engraulidae).
sprat {brisling}.
northern {herring, fish} (Clupeidae).
Small fish {pilchard, fish} can include sardines.
small, northern, silver, ocean and fresh water {smelt, fish}.
small European herring {sprat} (Clupea sprattus).
young or small pike {pickerel, fish}.
long, slender, duckbill {pike, fish}.
Teleosts {salmon, fish} (Salmonidae) can spawn in fresh water and live in sea, returning to home stream by smell.
northern coastal Atlantic, pink inside {Atlantic salmon}.
salmon {sockeye salmon}.
medium to large size, silver {trout, fish}.
very large {piracucu} {paiche} {arapaima} (Arapaima gigas).
North America, lake {bass, fish}.
east and central United States sunfish {bluegill}.
smooth skin, large flat head, long hairs {barbel} near mouth, ocean and freshwater {catfish}.
Europe, thick, spindle shape {chub}.
east Asia, red-orange color {goldfish} (Carassius auratus).
fresh water or ocean {mullet} (Mugilidae).
South America, tropical {piranha} (Serrasalmus).
Male fish {stickleback} can fight fish with red underbellies and court fish without red underbellies {key stimulus}. Stickleback fish build nests, using innate behavior.
small, South America and West Indies {guppy}.
live young, North and Central America {swordtail} (Poecilidae) (Cyprinodontiformes), related to southern platyfish {platy}.
small, striped, tropical, India {zebra fish} (Brachydanio rerio).
Fish {electric fish} (Gymnarchus) tail can generate weak electric voltages that cause discharges at 300/second. Electric organs along body detect electric field. Dorsal fin undulates to move fish forward without using tail. Objects in water alter electric field.
eel-like, South America {electric eel}.
Perciformes, Percomorphi, or Acanthopteri {perciform fish} {percoid} are largest vertebrate order, are 40% of all fish, look like perch, have ray fin, and began in late Cretaceous.
northern {cod} (Gadus morhua) (Gadidae).
Antarctica and south South America {white-blooded fish} {ice fish} (Channichthyidae).
Zanclus cornutus {moorish idol} (Zanclidae) is small tropical marine fish. Genus Heniochus butterfly fishes resemble Moorish Idols.
fresh water or ocean {perch, fish}.
small, America {sunfish} (Centrarchidae).
amber color, fork tail, warm water {amberjack} (Carangidae) {carangid} {hamachi}.
percoid {jack fish}.
carnivore, bluefin/horse mackerel, tropical {pilot fish} (Naucrates duclor).
tuna-like {skipjack} (Euthynnus).
tuna {albacore, fish}.
tuna {bigeye}.
large tuna {bluefin} {horse mackerel}.
streamlined {bonito, fish} (Sarda).
tuna {yellowfin}.
tropical {tunny} (Thunnus).
northern {mackerel, fish}.
Some jawed bony fish {salt-water lobe-finned fish} {lobefin fish} had lobefins, allowing crawling onto shore. Later, stumps became appendages.
lung
Nasal passages had internal nares openings into windpipe inside body, allowing more efficient breathing, moist and filtered air, and alternative air paths.
types
Rhipidistians are extinct. Later, Rhipidistians evolved to amphibians. Coelacanth fish (Crossopterygii) still survive today and are like Rhipidistians.
Paleozoic fish {coelacanth} are large, are bright blue to brown, have lobefins, and live in deep ocean.
Some lobefin fish {fresh-water lobefin fish} {fresh-water lobe-finned fish} had adults that lived in fresh water and on land.
fresh water
Because fresh water has no salt, they had to maintain hydrogen and salt ion balance in blood and tissues and had to control water drinking. Seawater ion balance is similar to that in cells. To live in fresh water, organisms need to pump out cell water to maintain salt and protein concentrations and to prevent bursting.
hind limb
Rear lobefins became specialized for pushing. Later, they became legs.
teeth
Teeth were for grasping but not cutting or grinding. Teeth grew, fell out, and grew back, repeating as animals grew.
hearing
Eardrum amplified sound for better hearing.
lung
They breathed using lungs. They had no gill bones and began gill loss. Later, gills closed.
evolution
Land vertebrates evolved from lobe-finned bony fish.
lobe-finned fish and tetrapods {sarcopterygian}.
Lobe-finned fish one meter long developed into four-legged fish {tetrapod}| (Tetrapoda) in shallow, plant-filled, fresh or brackish water, in tropics and subtropics. Perhaps, front limbs helped lift head above water to get more oxygen.
fins
Pectoral and pelvic fins gained feet and toes. Tetrapods have no tail fins.
bone
Vertebrae became interlocking. Neck became flexible after losing bones that joined head and shoulders. Snout became longer and head flatter. Gill and neck bones {opercular bone, tetrapod} disappeared. Longer ribs appeared. Pelvis became larger.
evolution
Most early lobefin fish were not tetrapod ancestors: Kenichthys [-400000000], Osteolepidids [-394000000], Eusthenopteron [-388000000], Panderichthys [-385000000], Elpistostege [-384000000], and Livoniana [-384000000]. Most early tetrapods are extinct and were not living-tetrapod ancestors: Elginerpeton [-378000000], Ventastega [-370000000], Acanthostega [-368000000], Ichthyostega [-366000000], and Tulerpeton [-364000000].
Sarcopterygians {lung fish} {lungfish} can have one or two lungs, live in freshwater, and have lobefins.
Frogs, toads, basilisk lizards, and salamanders {amphibian} are cold-blooded.
skeleton: palate
Cartilage secondary palate allows breathing and eating at same time, by closing either nose or mouth.
skeleton: neck
Joint between head and trunk {neck, amphibian} allows head scanning and turning.
skeleton: pelvis
Amphibians have a pelvis, allowing hind limbs more mobility on land.
skin
Amphibians have vascularized smooth and moist skin, which can change color using pituitary intermedin hormone. Some amphibians secrete poison.
skin: claws
Claws allow better grasping by hands and feet, for better traction on land.
circulation
Four-chambered heart, divided into auricle and ventricle for pumping blood to lungs and auricle and ventricle for pumping blood to body, allows blood circulation through lungs and improved respiration.
lung
Amphibians have primitive lungs.
excretion
Amphibians have kidneys to regulate hydrogen and salt ion balance.
reproduction
Amphibians reproduce like fish.
senses: smell
Pharynx-top vomeronasal system is for olfaction, mainly for pheromones, and depends on different genes than olfactory bulb.
senses: vision
Thalamus and optic tectum evolved for vision, possibly localizing objects and detecting size.
nervous system
Amphibians can detect motion and location and use behaviors that require knowing trajectories and depth. They represent sensations in midbrain.
evolution
Amphibians evolved from Rhipidistian lobefin fish.
development
Like chordates, life stages are egg, larva, and adult. Egg and larval stages live in water. Adults stay on land. Eggs become tadpoles, which have gills, eat plants, and metamorphose to adults. Metamorphosis is under thyroid-gland control, releasing hormone after pituitary-gland signal.
regeneration
Salamanders can regenerate legs and tails.
Amphibians have soft palates {secondary palate}, allowing breathing and eating at same time by closing either nose or mouth.
Amphibians reproduce as fish do. Eggs become larvae {tadpole}|, which have gills, eat plants, and metamorphose to adults.
Toad or frog larvae {polliwog} initially have no legs, have gills, and live in water.
Mexican Ambystoma salamanders {axolotl} can retain gills and mature without metamorphosis.
Frogs {bull frog} can be large, with low croaks.
Amphibians {frog} can identify flies as small-size dark spots moving at rates. Frogs do not perform complex shape analysis [Lettvin et al., 1959]. Some tropical frogs have skin alkaloid poisons {pumiliotoxin}, such as PTX 251D.
small salamander {newt}.
small, lizard shape {salamander, amphibian}.
land, rough skin {toad}.
First reptiles {stem reptile} were anapsids. Cut-lizard cotylosaur was low, stocky, and 20 centimeters to two meters long. Reptilia {reptile} include gecko, snake, iguana, turtle, crocodile, alligator, and lizard.
classes
The six reptile subclasses have different skulls: anapsid, diapsid, euryapsid, parapsid, synapsid, and therapsid.
evolution
Evolution was anapsid to diapsid to synapsid to therapsid. Euryapsids and parapsids evolved from diapsids.
land
Reptiles can live whole life cycle on land.
development
Reptiles have no larval stage in water. They develop continuously from egg to adult, requiring mechanisms for replacement and renewal.
skin
Thick dry leathery skin, with horny scales, allows continuous dry land existence, because it conserves water.
respiration
Reptiles have lungs.
skeleton: bone
Bones have growth rings in seasonal climates, with few blood vessels and haversian canals.
skeleton: pelvis
Reptiles have a strong pelvis, allowing running and/or standing on hind legs.
skeleton: jaw
Reptiles have muscles and jaws for chewing, not just grasping and tearing.
reproduction
Reptiles reproduce by intercourse and have internal fertilization. They lay eggs with leathery shells on land. An egg sac {amnion} holds water, so egg does not need to get water from sea, lake, or stream. Reptiles have egg-laying rituals, courtship rituals, territoriality, and sexual intercourse behaviors.
cloaca
The same body opening is for anus and reproductive tract.
muscle
Reptiles have only involuntary muscles controlled by automatic neuron circuits in ganglia and paleocortex.
nervous system
Cerebellum outer-layer basket cells process sensorimotor information and allow walking, running, and chewing. Brains have two-layered cortex and several ganglia. Paleocortex controls involuntary muscles and glands. Cortical neurons send axons to other cell layers and regions and receive signals from other paleocortex layers and regions. Paleocortex areas analyze information.
senses
Sense organs with more than one cell layer preprocess signals before sending them to brain. Median eye detects infrared light and later became pineal gland.
Early reptiles were, and most reptiles are, cold-blooded animals {poikilotherm}|.
Therapsid warm-blooded animals {endotherm}| had basal metabolism four times higher than poikilotherms and needed 10 to 30 times more food than poikilotherms.
The same body opening {cloaca}| can be for anus and reproductive tract.
Reptiles have two-layered nerve sheets {paleocortex}| connected to several ganglia, allowing more complex information processing and distribution. Paleocortex cerebrum covers forebrain and has distinct input layer and output layer.
Geckoes tilt toe hairs 30 degrees to let go while walking {toe peeling, hair}|.
Reptiles have one eye {median eye}| to detect infrared light. Later, median eye evolved to become pineal gland.
In reptiles, skull front-middle eye {parietal eye}| {third eye} detects sunlight level, regulates daily activities, and regulates seasonal responses to light and temperature. Parietal-eye light level affects puberty, sexual activity, hibernation, and aestivation.
Reptiles {reptile types} are anapsids, diapsids, synapsids, and therapsids.
Anapsids {anapsid} (Anapsida) were the first reptiles and are mostly extinct, except for turtles and tortoises (Chelonia), which have hard shells. Cut-lizards {cotylosaur} {cut-lizard} were low, stocky, two meters long, and the most-primitive reptiles. Other reptiles evolved from cut-lizard anapsids.
Chelonia {chelonian} are turtles and tortoises.
Sea turtles {sea turtle} have flipper legs and bony shells and lay eggs on shore.
Freshwater turtles {snapping turtle} (Chelydridae) can have rough shells and hooked beaks.
Aquatic turtles {soft-shelled turtle} can have flat flexible shells with leathery skin.
fresh water, North American, web-footed, tortoise {terrapin}.
plant eater, land, claws {tortoise, reptile} (Testudinidae).
beak, bony or leathery shell {turtle}.
Extinct aquatic reptiles {euryapsid} (Euryapsida) had long necks, small heads, long tails, and bloated bodies. They paddled, swam, and were up to 17 meters long, such as elasmosaurus. Euryapsids evolved from anapsids.
Diapsids {diapsid} (Diapsida) include tuatara, rhynchocephalia, extinct sphenodon, extinct ichthyosaur, and lepidosaurs. Lepidosaurs became squamata snakes and lizards.
evolution
Diapsids came from anapsids. Diapsids evolved to parasids and synapsids.
parietal eye
Parietal eye detected sunlight level and helped regulate daily activities and responses to light and temperature.
neck joint
New neck joint type, between head and trunk, put head at angle to vertebrae. Head turns around different axis than trunk, allowing freer head movement and improved ability to catch and eat prey. The new turning axis required triangulation to locate objects in space.
teeth
New teeth types were for cutting and chewing, to match new jaw types.
Diapsids include scaled lizards {lepidosaur} {scaled lizard}. Lepidosaurs became squamata, which became snakes and lizards.
snakes and lizards {squamata}.
Squamata {lizard} can have four legs, scales, and tails.
American Basiliscus lizards {basilisk} have crests and can run on hind legs.
Lizards {chameleon} can change color.
Lizards {gecko} can have 500,000 hairs {setae} on each foot. Hairs split into hundreds of ends. If ends are perpendicular to surface, they stick by van der Waals forces. Geckos tilt toe hairs 30 degrees to let go while walking {toe peeling, gecko}.
large {Gila monster}.
Lizards {horned toad} can have head horns and body spines.
horned {iguana}.
large {monitor lizard}.
Squamata {snake, animal} can have scales and no legs.
long thin ocean snake {sea snake}.
swimming snake {water snake}.
constrictor {anaconda}.
constrictor {boa constrictor}.
constrictor, jungle {python}.
poison {adder}.
poison {asp}.
poison {black adder}.
poison, forest {bushmaster}.
poison {cobra}.
poison {copperhead}.
poison {coral snake}.
poison, woods {cottonmouth}.
poison {pit viper}.
poison, desert {rattlesnake}.
poison, desert {sidewinder}.
poison {viper}.
poison, swimming {water mocassin}.
Diapsids {sphenodon} were one meter long, had large beak-like snouts, and had spines down back. They are extinct. Sphenodons had third eyes. They had nictating membranes. Sphenodons were archosaur ancestors.
Diapsids {rhynchocephalia} {rhynchosaur} were small, had beaks, and included sphenodon.
Diapsids {archosaur} had two large back limbs, two small front limbs, long tails, and teeth in sockets. They are extinct. Archosaurs evolved from sphenodons. Archosaurs include thecodonts.
Diapsids {thecodont} had insulation, had reptilian teeth, and included Troödon, Pterodactyl, and Pteranodon [-220000000]. They are extinct. Thecodonts came from archosaurs. They are bird, crocodile, sauropod, thecopod, pterosaur, Ornithischia, and Saurischia ancestors.
Thecodonts {pterosaur} (Pterosaura) had webbed wings on little fingers. Perhaps, pterosaurs had hair. They had light and long heads. Early pterosaurs had teeth and long tails, but later ones had neither. They are extinct. Pteranodon had seven-meter wingspan. Pterodactyl flew. Birds evolved from pterosaurs.
extinct flying reptile {pterodactyl}.
Thecodonts (Ornithischia) {bird hip} were herbivores. Ornithischia evolved from thecodonts. Anatosaurus had duckbill with flat wide jaw. Ankylosaurus had large bony plates on back, spikes on sides, and bony ball at tail tip. Triceratops had three horns on head and broad bone on neck.
Ornithischians {stegosaur} can eat plants, have back bony plates, and have spiked tails.
Crocodiles and alligators (Crocodilia) {crocodile, animal} evolved from thecodonts.
broad short snout {alligator}.
American, related to alligators {caiman}.
Extinct thecodonts {crurotarsan}| were like large crocodiles. Crurotarsans included phytosaurs, rauisuchians, and aetosaurs. Phytosaurs lived in water and were up to 13 meters long. Rauisuchians lived on land and were up to 10 meters long. Aetosaurs had armor. They flourished from 230 million years ago to 201 million years ago, until Late Triassic catastrophe, which dinosaurs survived. Crurotarsans are crocodile and alligator ancestors.
Thecodonts (Saurischia) {lizard hip} were bipeds with feet like thecopods or quadrupeds with feet like sauropods. They are extinct.
Saurischia quadrupeds {sauropod} had feet like lizards. Sauropods were large plant eaters. They had long necks and tails. They included Brontosaurus, Brachiosaurus, Diplodocus, and Apatosaurus. They are extinct. Prosauropods hatched with no teeth, four legs, and short tail. Perhaps, parents fed them. After they hatched, neck grew, tail lengthened, and forelimbs did not grow. Later sauropods had four legs and derived from juvenile stage.
vegetarian {brontosaur}.
Extinct Saurischia bipeds {thecopod} had feet like mammals.
Extinct Saurischia {theropod} had feet like mammals, were coelurosaurs or carnosaurs, were cold-blooded, had large range, and had few competitors.
Extinct theropods {carnosaur} were large meat eaters, such as Tyrannosaurus, Carcharodontosaurus, and Spinosaurus.
Extinct theropods {tyrannosaurus} were carnivores, had two legs, and had short arms.
Extinct theropods {coelurosaur} were fast meat eaters with tails and long necks.
Extinct theropods {gigantosaur} (Mapusaurus roseae) were carnivores.
Parasids {parasid} (Parasida) include extinct fish-lizard ichthyosaurs. Parasids lived in ocean, were one to twenty meters long, and had long noses. Parasids evolved from diapsids.
Extinct parasids {ichthyosaur} lived in ocean 245 million to 90 million years ago. At first, they were lizard-like and undulated like eels and then were fish-like and flipped tails like fish. They were one to twenty meters long, had long noses, were carnivores, and ate mostly animals like squid. Like all non-mammals, they had very large eyes with sclerotic rings.
Synapsids {synapsid} (Synapsida) had new joint type between head and trunk, so head was at angle to vertebrae and turned around different axis than trunk, which later led to free head movement. They had new teeth types for cutting and chewing. They are extinct. Synapsids came from diapsids. They are therapsid and mammal ancestors.
Extinct finback mammal-like synapsids {pelycosaur} were 60 centimeters long, had canine teeth, and chewed using jaw and jaw muscles different than anapsids and diapsids. Two-meter-long Dimetrodon had dorsal fin for warming and cooling blood [-260000000]. Pelycosaur species became Pristerognathids.
Extinct synapsids {pristerognathid} weighed 50 kilograms, were fast trotters, were endotherms, and included antesaurus, gorgon, and moschorhinids. They evolved from pelycosaurs. They gave rise to therapsids.
Extinct synapsids {therapsid} lived in south Gondwana.
endotherm
As endotherm warm-blooded animals, with basal metabolism four times higher than poikilotherm cold-blooded animals, they needed 10 to 30 times more food. Optimum temperature for metabolism uses heating and cooling mechanisms {thermoregulation, endotherm}, resulting in much higher available energy all day and allowing more activity throughout day, rather than just at midday.
hair
Hair or feathers helps temperature regulation.
hearing
Warm-bloodedness requires better hearing, because daily activity requires more warning signals and other communications. Therapsids had ear pinnae to gather sound better.
larynx
Therapsids had larynx, allowing sound production, accompanied by ability to hear and find meaning in sounds.
evolution
Therapsids evolved from Pristerognathids. Therapsids are mammal ancestors.
Therapsids had outer ear structures {ear pinna}, to gather sound better.
Therapsids had optimum temperature for metabolism, maintained by heating and cooling mechanisms {thermoregulation, therapsid}|.
Extinct therapsids {cynodontia} {cynodont} were dog-sized, were nocturnal, and slept curled up.
rib
They do not have lumbar-vertebrae ribs.
jaw
Lower jaw had dentary bone and had big canine teeth, incisors, and molars with multiple cusps. Snout and lips had muscles, possibly to suckle, and possibly whiskers.
palate
Hard palate enabled simultaneous breathing and chewing.
smell
Turbinals held olfactory receptors and warmed and humidified air. Number of olfactory genes became thousand, by gene duplication.
eye
Being nocturnal, they had large eyes and post-orbital bar.
They also had parietal eye.
evolution
They evolved from therapsids. They were mammal ancestors.
types
Cynodonts included Thrinaxadons and Procynosuchus.
Cynodont lower jaw had one main bone {dentary} and had big canine teeth, incisors, and molars with multiple cusps.
Extinct separate therapsids {dicynodont} were herbivores and included Lystrosaurus.
Cynodonts {Chiniquodontid} had teeth for meat eating.
Leopard-sized cynodont plant-eaters {traversodontid} had incisors and cheek teeth.
Birds {bird} have wings and feathers.
feathers
Feathers are modified reptile scales, decrease water and heat loss, and aid flying. Light scattering causes blue jays to have blue feathers. Transparency causes white feathers [Matthews, 1973]. Females typically are drab, and males have color.
flying
Bigger birds fly faster. Penguins cannot fly but use wings for swimming by flying under water.
bone
Birds have hollow bones.
metabolism
Birds live several years. They have fast heartbeat, high blood sugar, and high blood pressure. They have fast transit time for digestion. Birds are warm-blooded.
respiration
Birds have lungs that exhale actively and inhale passively, by continuous airflow, because lung air sacs fill spaces between organs and in wings.
reproduction
Birds have fertilization inside female. Birds have eggs with hard shells.
signals
Birds have 10 to 40 different signals [Matthews, 1973]. Bird songs {birdsong} can be instinctual, learned, or irregular and are for warning, mating, or territory.
nervous system
Birds have optic tectum.
development
Both parents care for eggs and chicks.
evolution
Birds evolved from thecodont pterosaurs.
types
Protoavis [-220000000] had good eyes and bad olfaction and hunted by day. Special shoulder joints allowed later flying, as in Archaeopteryx [-150000000] and Confuciusornis sanctus [-120000000].
high nest {aerie}|.
Birds have lungs that exhale actively and inhale passively, by continuous airflow, because lung extensions {air sac, bird} fill spaces between organs and in wings.
Birds are warm-blooded {homoiothermic, bird} {homoiotherm}|, with high body temperature, 107 F to 113 F.
Some birds winter in one location and summer in another location {migration, bird}, up to 12,000 miles apart. Daylight change affects hypothalamus and pituitary, which affect gonads, which start migration. Increased sex hormones start migration. Migratory birds and homing pigeons use Sun, Moon, Earth magnetic field, air pressure, polarized-light plane, and star-field rotation to establish north-south axis and general directions. They use wind direction, other-bird call notes, and landmarks when close to home.
In extremities, water birds have blood vessels {rete mirabile}| that conserve heat and oxygen pressure by countercurrent exchange.
Ostrich has rudimentary {vestigial}| wings.
Anterior-forebrain region {wulst}| has a visual map.
young swan {cygnet}.
Young birds {fledgling bird}| have feathers but cannot fly.
baby goose {gosling}.
baby bird {hatchling}|.
small rooster {bantam rooster}.
rooster {cock}.
male duck {drake}.
male goose {gander}.
female bird {hen}|.
first-year hen {pullet}|.
male chicken {rooster}.
shot or captured bird set {brace, bird}|.
Baby-bird set {brood}| can be from one mating season.
small quail or partridge family or flock {covey}|.
geese group {gaggle}|.
bird nesting place {rookery}|.
small, hovers, long bill, drinks nectar {hummingbird}.
Large tail can expand upward {peacock, bird}.
running, crested, southwest North America, brown {roadrunner}. Geococcyx californianus.
feathers, neck and feet scales, teeth, claws {archaeopteryx}.
extinct large bird {dodo}.
large, black {blackbird} {red-winged blackbird} {yellow-headed blackbird}.
North-American blackbird {cowbird}.
large, black, American blackbird {grackle}.
tropical Asian starlings {mynah bird}.
medium size {redwing blackbird}.
medium-size {starling}.
In Australia, male birds {bower bird} build bowers to attract females.
bower bird {catbird}.
Corvids {corvid} include ravens, crows, jays, magpies, and nutcrackers.
large, black {crow}. New Caledonian crow can put things together to make tool to get food from inside hole.
long tail, black-and-white, harsh call {magpie}.
Large, black crow-like birds {raven} (Corvus corax) eat mostly carrion and hide pieces over kilometer radius. They make pretend hiding places. They cut and arrange food pieces so they can carry them.
size
They weigh more than kilogram and have wingspan more than meter.
skills
They operate in environment with many other ravens competing for food. They observe situation then choose action. They can distinguish species individuals and large predators. They like to play, roll on back, throw small pebbles at predators using beaks, and lead predators to prey. They play with large predators when young and eat near them when old. They can make and manipulate tools.
European crow-like bird {rook}.
medium size, black, loud call {jay}. Scrub jay can put different food in different places and different times, and remember food type, place, and time together. Perhaps, they have episodic memory, which requires what, when, and where.
medium size, blue, loud call {blue jay}.
Ducks {duck} have Herbst corpuscle vibration detectors, like Pacinian corpuscles, around bill.
medium size {mallard duck}.
medium size, diving {merganser} {sheldrake}.
medium size {teal}.
medium size {wood duck}.
medium size, plump body, feathered legs and feet {grouse, bird} {ruffed grouse} {arctic grouse} {ptarmigan}.
small {quail, bird}.
large {turkey, bird}.
medium size {goose, bird}.
large {Canada goose}.
large {loon}.
large {parrot, bird}.
small, blue {cockatoo}.
large, big beak {macaw}.
small, blue {parakeet}.
large, big beak {toucan}.
medium or large {penguin}.
large {Adelie penguin}.
medium size {petrel}.
medium size {stormy petrel, bird}.
medium size, white, short legs {pigeon}.
medium size, white, short legs {dove, bird}.
medium size, white, short legs {homing pigeon}.
medium size, gray, whimpering call, short legs {mourning dove}.
medium size, short legs {rock pigeon} {stock dove} {ringdove} {wood pigeon} {turtledove}.
medium size {plover}.
American plover {killdeer} lives in inland waters and fields and has unique call.
Large African birds {secretary bird} can eat reptiles and have long legs.
Old World, strong hooked bill {shrike} {loggerhead}.
large, scavenger {buzzard}.
large, scavenger {condor}.
large, scavenger {turkey buzzard}.
large, scavenger {vulture}.
large {eagle, bird}.
large {American eagle}.
large, white head {bald eagle}.
medium size {falcon}.
small {peregrine falcon}.
medium to small {hawk, bird}.
small {nighthawk} {bullbat} {mosquito hawk}.
small {sparrowhawk}.
Owls {owl, bird} have no independent eye movement but have head-movement map in optic tectum.
medium size {barn owl}.
medium size {great horned owl}.
medium size {screech owl}.
ostrich, emu, rhea, kiwi {ratite}.
large, flightless, Australia, related to ostrich and cassowary {emu} (Dromiceius novaehollandiae).
small, flightless, New Zealand {kiwi, bird} (Apteryx) (Apterygidae).
large, white, very large egg {ostrich}.
Birds {wading bird} can walk in shallow water to find small grubs and fish.
large {crane, bird}.
large, brownish, wading {curlew}.
heron, long white feathers {egret}.
large, pink {flamingo}.
medium size {heron}.
wading, temperate and tropical climates {ibis} (family Threskiornithidae).
medium size, marsh {rail, bird}.
medium size {sandpiper}.
medium size, shore {snipe}.
medium size {spoonbill}.
medium size, wading {stilt}.
large {stork}.
medium size migratory, related to snipe and sandpiper {woodcock, bird}.
Cardinals, sparrows, bluebirds, and other birds {songbird} make melody, perch (Passeriformes) {perching bird}, and build nests.
small {bluebird}.
medium size {bobolink}.
medium size {bob-white}.
North America, bill curves down {brown creeper}.
small {bunting, bird}.
small {canary}.
medium size {cardinal, bird}.
small {chickadee}.
Other birds hatch its eggs {cuckoo}.
small {goldfinch}.
small {indigo bunting}.
medium size {nightingale}.
small {nuthatch}.
North American medium-size bird {phoebe} flicks tail.
large, North American, {purple martin}.
medium size {redbird}.
medium size {robin}.
small {sparrow} {English sparrow} {chipping sparrow} {song sparrow} {white crowned sparrow} {white throated sparrow}.
small {titmouse} {tit}.
medium size, eats insects {vireo}.
medium size {waxwing} {cedar waxwing}.
medium size {whippoorwill}.
small {wren} {house wren} {cactus wren}.
small {finch}.
long-tailed, American {towhee}.
medium size {lark}.
medium size {meadowlark}.
medium size {skylark}.
medium size {oriole}.
medium size {Baltimore oriole}.
medium size {tanager}.
medium size {scarlet tanager}.
medium size {thrasher}.
small {brown thrasher}.
Medium-size thrashers {mockingbird} can imitate bird calls.
medium size {thrush} {wood thrush} {hermit thrush}.
medium size {chat, bird}.
medium size {warbler}.
American warblers {ovenbird} can make dome-shaped nests on dirt.
medium size {yellowthroat}.
medium size {swallow}.
medium size {barn swallow}.
medium size {flycatcher}.
large, American, flycatcher {kingbird}.
medium size {swift} {chimney swift}.
large {swan}.
large {trumpeter swan}.
wading or swimming birds {waterfowl}.
large {albatross}.
large, extinct {auk}.
medium size {bittern}.
medium size {coot}.
large {cormorant}.
swimming, diving {grebe}.
medium size {gull}.
large {kingfisher}.
large {osprey}.
large {pelican}.
medium size {sea gull}.
medium size {tern}.
Herbst corpuscle vibration detectors, like Pacinian corpuscles, are in tongue {woodpecker} {downy woodpecker} {pileated woodpecker} {redheaded woodpecker}.
medium size, North American {flicker}.
Small American woodpecker {sapsucker} eats sap from apple and maple trees.
Mammals {mammal} evolved from therapsids.
types
Mammals (Eutheria) are extinct multituberculates, monotremes like platypus, marsupials like kangaroo, and placental mammals (Placentalia).
evolution
Eutheria evolved from Theria. Early mammals included 30-gram Megazostrodon [-220000000] and Triconodon.
behavior
Early mammals hunted alone, signaled, and had territoriality. Voluntary muscles allowed rapid locomotion and good control.
body temperature
More food and oxygen allowed higher metabolic rate, more muscle action, and warm-bloodedness {homoiothermic, mammal}. Body temperature was higher than surroundings but lower than humans have now. Homeostasis allowed wider territory ranges and longer maturation times. Because early mammals were nocturnal, they only needed heating. Panting and sweating to cool body came later.
body temperature: hair
Mammals have hair, rather than scales, plates, or feathers, covering skin, to aid thermoregulation and insulation. They have sweat glands.
respiration
Diaphragm, bony palate, and turbinals allowed more oxygen and better respiration. Specialized red-blood-cell erythrocytes carry heme to provided better energy and oxygen management. Only warm-blooded animals can have erythrocytes.
reproduction
Reproductive-tract and digestive-tract openings became separate, allowing better and more reproduction and childcare varieties. Early mammals had birth rituals, courtship rituals, and sexual intercourse.
reproduction: mammaries
Sweat glands evolved into mammary glands, which provided balanced nutrition to young. Only warm-blooded animals can make milk. Milk redefined mother and father roles relative to children and allowed longer maturation and more brain growth. Mothers cared for babies until weaning.
teeth
Mammals have three teeth types: incisor, canine, and molar. They have two teeth sets, baby and adult, instead of continuous replacement, allowing head to be greater size in early life. Deciduous baby teeth and permanent adult teeth, rather than having continual replacement, allowed more teeth variety and more chewing. Head can be greater size in early life.
nervous system
Hippocampus and archicortex replaced some thalamus functions. Larger cerebellum allowed more sensorimotor coordination.
nervous system: involuntary muscle
Automatic circuits in ganglia and paleocortex control involuntary muscles, as in reptiles and birds. In lower mammals, archicortex and mesocortex or paleocortex add a supragranular layer to lower-animal granular and subgranular layers. In middle mammals, both supragranular and granular layers thicken, but subgranular layer stays the same.
nervous system: neocortex
In higher mammals, neocortex thickens, cellular complexity increases, newborn unmyelinated areas increase, and brain has more fissures. Paleocortex extension above ganglia forms neocortex to control voluntary muscles. All mammals have four lobes and three fissures in neocortex. Neocortex had four layers with minicolumns and interconnected specialized modules, to make maps for more complex local processing and more integration. Larger cerebrum allowed more spatial and temporal integration.
Higher mammals try alternate strategies to reach goals and identify object and event categories, such as individuals, selves, space, and time. Some mammals learn abstract symbols and categories. Some mammals generalize from specifics and specify objects from general categories. Some mammals learn relationships but cannot use analogies, metaphors, similes, parables, and mental models. Mammals have pleasant and unpleasant dreams. Mammals are curious, sentient, and know object categories, not just specific objects.
senses
Animals evolved new sensation abilities [Dawkins, 1987] [Griffin, 1974] [Griffin, 2001] [Griffin and Speck, 2004] [Haugeland, 1997].
senses: smell
Smell sense developed first, in amygdala and forebrain paleocortex.
senses: vision
At first, small eyes bulged out, as in tree shrews. Optic tectum allowed better object localization and size detection. Mammals typically have no or limited color vision, except for primates.
senses: hearing
Maleus evolved from cynodont articular jawbone, and incus evolved from cynodont quadrate jawbone, to work with stapes. Stapedius muscle controlled stiffness. Outer hair cells paralleled inner hair cells. These allowed hearing frequencies above 10000 Hertz and so high-frequency insect noises and baby cries. Outer hair cells can also change shape quickly, changing frequencies to which inner hair cells respond best. Early mammals had ear pinnae.
Mammals developed from juvenile therapsid cynodonts that matured quickly {pedomorphism}|.
People modified animals {domesticated animal}.
In Eurasia and north Africa, cow and ox came from auroch.
In west and central Asia, sheep came from Asiatic mouflon sheep.
In west Asia highlands, goat came from bezoar goat.
In Eurasia and north Africa, pig came from wild boar.
In south Russia, horse came from wild horses.
In Andes mountains, llama and alpaca came from guanaco.
In north Africa, donkey came from African wild ass.
In southeast Asia, bali cattle came from banteng, which relates to auroch.
In India and Burma, mithan came from gaur, which relates to auroch.
Arabian camel was in Arabia. Bactrian camel was in central Asia.
Reindeer were in north Eurasia. Water buffalo was in southeast Asia. Yak was in Himalayas and Tibet.
Primates live on ground or in small tree branches {fine-branch niche}|, like Australia and South America small nocturnal prosimians and arboreal marsupials.
Early placental mammals had long, sensitive snouts with large hairs {vibrissae} and good smell sense.
female quadruped {dam}.
flock or herd {drove}|.
Animals can have babies {pup, litter} each mating season {litter, pup}|.
Lions live in groups {pride}| with two or three males and five to ten females and cubs.
Mammals besides humans show paw preferences {handedness, mammal} but equally to left or right.
Mammal superior colliculus can integrate multiple senses {multisensory} at same spatial location, while other structures maintain distinct sensations for each sense [O'Regan and Noë, 2001].
Arginine vasopressin aids pair bonding {pair bonding, arginine vasopressin}.
Vocalization echoes give information. Dolphins and bats expanded this ability. Dolphins and bats use sonar {sonar, animal} to locate and categorize objects. They can project known signals into environment, receive reflected signals, and interpret altered signals. Signaling evolved from vocalization. Receiving evolved from auditory-brain sound processing, which locates and categorizes sounds.
Animals that are smart enough to suffer include horse, dog, apes, elephants, and dolphins, because they can do something about conditions that make them suffer {suffering, animal}.
Animal rhythms {biological rhythm}| depend on year, lunar month, tides, and day.
brain clock
Brain can time intervals {brain clock} using striato-cortical loops and frontal-cortex, caudate-putamen, and thalamus dopamine neurons. Clocks can be neuron circuits for each time interval, or neuron populations can code all intervals. Somatosensory lemniscal system can backdate events.
millisecond rhythm
Biochemical reactions have millisecond intervals. Coupled reaction systems can have cycles up to 100 seconds.
second rhythm
Heartbeat has ultradian rhythm regulated by pacemaker-neuron membrane-potential changes by voltage-sensitive K-channels.
minute rhythm
Cycles can repeat every few seconds or minutes for sessile, burrowing, and boring animals. Protein regulates cell 12-minute growth cycles. Inositol-trisphosphate receptor regulates calcium release in C. elegans in fifty-second intervals.
day rhythm
People can live on 23-hour and 25-hour cycles.
development rhythm
Reaction-cycle superpositions cause development cycles, which have intervals from minutes to hours to days.
month rhythm
Biological rhythms can be monthly, for hormones and temperature. Sex-hormone levels vary over lunar month. Marine organisms feed or rest with lunar tides. Shore-living invertebrates typically have tidal cycles and long-term rhythms related to Moon cycles.
year rhythm
Biological rhythms can be yearly, for migrations and moods. Yearly rhythms include hibernation and estivation. Breeding seasons typically are yearly. In autumn, plants can die or start low-metabolism state {dormancy, plant}.
In mammals, Mop3 gene product is main component of 24-hour biological clocks {biological clock}|, in hypothalamus, eye, testis, ovary, liver, heart, lung, and kidney, which work by positive and negative feedback among proteins. Mammals can rest themselves according to environment. Mutant Mop3 requires homozygosity. Clock-gene product acts as a pacemaker in hypothalamus suprachiasmatic nucleus (SCN), which synchronizes other organ clocks. CLOCK, PER, and MOP3 proteins have PAS domains. Circadian rhythm affects albumin D-element-binding protein {mDbp}, which does not regulate circadian rhythm.
Neuron networks {central pattern generator} control breathing, walking, and swimming.
Body has daily activity patterns {circadian rhythm}|. Internal mechanisms for daily cycles have 24-hour cycles.
functions
Body temperature, activity, blood pressure, blood pulse rate, blood volume, hormone levels, eosinophil levels, ACTH concentration, cortisol concentration, magnesium concentration, calcium concentration, 17-hydroxycorticosteroid concentration, sodium concentration, potassium concentration, catecholamine concentration, and phosphate concentration vary over day.
functions: time of day
Labor is most frequent and T lymphocytes are most at 1 AM. Growth hormone and deep sleep are greatest at 2 AM. Asthma attacks are most frequent at 4 AM. Body temperature is lowest at 4:30 AM. Menstruation starts most frequently at 6 AM. Insulin, blood pressure, heart rate, and cortisol are lowest at 6 AM, but melatonin is highest. Blood pressure starts to rise at 6:45 AM. Hay fever is worst at 7 AM. Melatonin production stops at 7:30 AM. Heart attack and stroke are most frequent at 8 AM. Rheumatoid arthritis is worst at 8 AM. T lymphocytes are fewest at 8 AM. Bowel movements are most likely at 8:30 AM. Alertness is highest at 10 AM. Blood hemoglobin concentration is highest at 12 PM. Coordination is best at 2:30 PM. Respiration is fastest, reflexes are quickest, and hand grip is strongest at 3 PM to 3:30 PM. Body temperature, heart rate, and blood pressure are highest at 4 PM. Muscle strength is greatest at 5 PM. Urination is most frequent at 6 PM. Blood pressure is highest at 6:30 PM. Body temperature is highest at 6:30 PM. Sensitivity to pain is greatest at 9 PM. Melatonin production starts at 9 PM, induces sleep at night, and maximizes just before morning. Bowel movements stop at 10:30 PM. Allergic reaction is most frequent at 11 PM.
cycle
Light affects retinal ganglion-cell melanopsin receptors, which catabolize PERIOD (PER) and TIMELESS (TIM) protein complexes in cytoplasm. Six hours later, catabolism is complete and CYCLE and CLOCK proteins bind. Then combined proteins bind to PER and TIM genes in cell nucleus, to start transcription. Six hours later, PER and TIM proteins bind in cytoplasm to form complex that blocks binding of CYCLE and CLOCK in cell nucleus.
After several days {jet lag}|, travelers can adjust to new local time. Travel across time zones can cause disturbances in sleep, digestion, and daily activity rhythms, and disturbances are unpleasant, impair performance, and last several days.
People have 90-minute to 100-minute cycles {ultradian rhythm}|. Desire to eat, desire for sex, sleep phases, daydreams, dreams, alertness, stomach contractions, and instinctual drives in general have ultradian rhythms. Infants have 60-minute movement and inactivity cycles.
Animals can have twilight activity {crepuscular}|.
Animals can have daytime activity {diurnal}|.
Animals can have nighttime activity {nocturnal}|.
Yearly rhythm is deep suspended animation, with low temperature, slow heartbeat, and slow breathing, for summer {estivation}|.
Yearly rhythm is deep suspended animation, with low temperature, slow heartbeat, and slow breathing, for winter {hibernation}|.
Main ancient mammals {Tribosphenida} had special-shape molar teeth {tribosphenic molar}.
Duck-billed platypus and spiny anteater {monotreme}| (Monotrema) are small. Monotremes evolved by pedomorphism from juvenile cynodonts that matured quickly. Monotremes lay eggs. Eggs hatch, and infants drink milk from mammary glands. Duck-billed platypus finds buried molluscs and insects by electric potentials.
Mammals {Theria} can have live births, rather than eggs laid outside body, and mammary glands. Eggs develop inside body. Babies emerge in fetal stage, requiring care of young during gestation and after birth. Parental care causes adult-behavior imitation. Theria developed from monotremes. Theria include Eutheria and marsupials.
Kangaroo, koala, wombat, wallaroo, and opossum {marsupial}| (Marsupia) {pouched mammal} have embryos that develop inside body and bear live young, at fetal stage, that crawl to pouch on abdomen outside, to drink milk from mammary glands and develop. Marsupials care for young. Theria developed from monotremes. Marsupials came from early Theria.
small, Australia, long snout, claws, termite eater {banded anteater}.
plant eater, Australia and New Guinea, large hind legs, long thick tail {kangaroo}.
Australia, arboreal, gray, furry ears, no tail {koala}.
nocturnal, arboreal, long tail {opossum} (Didelphis) (Didelphidae).
small, fur, Australia, arboreal, long prehensile tail {phalanger}.
Australia, aquatic, egg-laying, duck-like flexible bill, web feet, gray fur {platypus} (Ornithorhynchus anatinus).
small, carnivorous, black, long tail {Tasmanian devil}.
kangaroo-like but smaller {wallaby} (Macropodidae).
burrowing, plant eater, Australia, medium size, dense hair, short tail, flat snout {wombat}.
In Cretaceous, 150 million years ago to 100 million years ago, small, nocturnal insect-eaters {placental mammal}| (Placentalia) evolved.
anatomy: placenta
Tissue {placenta}, in which mother blood vessels commingle with embryo vessels, surrounds embryo inside uterus, allowing food and waste exchange. This allows more embryo growth, by improving nutrition and respiration.
anatomy: senses
First Eutheria had large ears and good hearing. They had vibrissae and good smell sense. They had small eyes, on head sides.
anatomy: nervous system
First Eutheria had larger brains than same-size reptiles.
biology: signal
Mammals other than primates have 10 to 40 different signals.
biology: children
All Eutheria have live birth. Eutheria have fewer births per mother, birth at later stage, and more care of young. Culture transmission requires relatively few young. Adults must outnumber young to preserve culture.
types
The 23 placental-mammal orders include bats, carnivores, cetacea, edentates, hooved, insectivores, primates, proboscids, rodents, scienia, and simple hooved. Carnivores include cat, dog, bear, and seal. Edentates include sloth, anteater, and armadillo. Insectivores include hedgehog, insectivore shrew, and mole. Primates include tree shrew, lemur, tarsier, and monkey. Lemurs and tarsiers are similar.
clades
Placental mammals have four clades. Clade I {Afrotheria} includes elephants, manatees, aardvarks, and elephant shrews. Clade II {Xenarthra} includes sloths, anteaters, and armadillos. Clade III {Euarchontoglires} {Supraprimates} includes rodents, primates, flying lemurs, and tree shrews. Clade IV {Laurasiatheria} includes cetaceans, bats, carnivores, hedgehogs, insectivore shrews, and moles.
clades: evolution
Afrotheria was first. Afrotheria and Xenarthra, clades I and II, split 103 to 105 million years ago, in Cretaceous, perhaps from South America and Africa separation.
Early superorder {Boreoeutheria}, of clades III Euarchontoglires and IV Laurasiatheria, split from Xenarthra 84 to 95 million years ago.
Euarchontoglires and Laurasiatheria {Epitheria} split 60 million years ago.
clades: I Afrotheria
Afrotheria is in Africa and includes golden mole (Chrysochloridae), otter shrew/tenrec, elephant shrew/sengi (Macroscelidea), aardvark (Tubulidentata), hyrax (Hyracoidea), mantee/dugong (Sirenia), and elephant (Proboscidea).
Tenrec (Tenrecidae) and otter shrew (Potamogalinae) have cloaca and can look like shrews, hedgehogs, mice, or otters. Golden mole lives in south Africa, eats insects, burrows, and looks like moles. Golden mole and otter shrew/tenrec are order (Afrosoricida).
Elephant shrew or jumping shrew (Macroscelididae) has long nose and looks like shrews.
Hyrax, mantee/dugong, and elephant are clade (Paenungulata). Hyrax lives in Africa and Middle East, looks like rabbit or guinea pig, and ferments food in cecum {copraphage}.
clades: II Xenarthra
Xenarthra developed in South America and includes armadillo (Cingulata), anteater (Vermilingua), and tree sloth (Folivora), which have strange joints {xenarthra}. Anteater includes silky anteater, giant anteater, and tamandua. Tree sloth includes two-toed and three-toed sloths. Anteater and tree sloth are group (Pilosa).
clades: III Euarchontoglires
Squirrel, mouse, and other rodents (Rodentia); rabbit, hare, and pika (Lagomorpha); treeshrew (Scandentia); coluga (Dermoptera); and primates are superorder (Euarchontoglires) (Supraprimates).
Coluga (Cynocephalidae) or cobego or flying lemur can glide from trees and lives in southeast Asia. Coluga, primate, and treeshrew are order (Euarchonta).
Pika (Ochotonidae), rock rabbit, or coney is like hamsters and squeaks {whistling hare}. Rodents and lagomorphs are order (Glires).
clades: IV Laurasiatheria
Laurasiatheria developed in Laurasia and are bats, hedgehogs, cetaceans, even-toed ungulates, odd-toed ungulates, carnivores, and scaly anteaters.
Hedgehogs (Erinaceinae) live in Eurasia and Africa. Gymnures or moonrats live in southeast Asia. Hedgehogs and gymnures are early order (Erinaceomorpha).
Shrews (Soricidae) include white-toothed shrews, red-toothed shrews, and African white-toothed shrews. Moles (Talpidae) include Talpinae, Scalopinae, and Uropsilinae. Solenodons (Solenodontidae) look like large shrews, are insectivores, and live in Cuba and Haiti. Moles, shrews, and solenodons (Soricomorpha) are order.
Artiodactyla order of even-toed ungulates includes pigs, hippopotamus, camels, giraffe, deer, antelope, cattle, sheep, and goats. Cetacea order includes whales, dolphins, and porpoises. Cetaceans probably evolved from hippopotamus (Whippomorpha) (Cetancodonta). Cetaceans and even-toed ungulates are order (Cetartiodactyla).
Even-toed and odd-toed ungulates are a group.
Order (Pegasoferae) is in Africa and south Asia and includes pangolins or scaly anteaters (Pholidota), carnivores (Carnivora), bats (Chiroptera), and odd-toed ungulates (Perissodactyla), such as horses. Carnivores and scaly anteaters are group (Ferae).
Mammals accept that individuals can have authority, resulting in different ranks {dominance hierarchy}|. Animals in groups have ranks or roles, relatively dominant or subordinate. Older males typically dominate.
authority
Different species use different authority symbols.
hierarchy
All societies have status hierarchies and/or resource controls.
change
Primates form alliances based on obligations and contact, to gain higher rank. Ranks are always shifting. Dominance fights are not deadly. Animals can try to act differently than rank. Others must catch and punish offenders. Animals can try to deceive, but only higher apes seem to try to make others' beliefs be wrong.
effects
Dominance hierarchy causes hostility to strangers, maintains peace in society, decreases new behaviors, and causes threats from younger males toward older males.
factors
Dominance behaviors increase at breeding times. Dominance behaviors increase at higher population densities.
Only humans laugh {laughter, human}, but other mammals appear happy.
Fat layer {blubber}| can protect body from cold.
Insectivores have hands with opposing thumb across from fingers {grasping hand}|, which allows better grip and more hand-eye coordination.
Some whales have oil {spermaceti}.
Proboscids have long trunk {trunk}| from nose.
Proboscids have elongated incisor teeth {tusk}|.
Insectivores have eyes facing front {forward vision}|, rather than on side, allowing better vision and eye-hand coordination and more space for brain frontal lobes.
Some echolocating bats, like horseshoe bat, scan for sound and then focus sound using nose structures {nose leaves}.
Cats have mirror-like layer {tapetum} behind retina to reflect light back through retina.
Individuals at rank must know to do some things and not do other things {deontic reasoning}.
Individuals in society attend to and remember rule breaking and act on previous-situation knowledge {indicative reasoning}.
Proboscids {proboscid}| (Proboscidea) have nose trunk, thick and loose skin, and tusks. They include elephant, mastodon, and wooly mammoth. Elephants can make infrasonic sounds.
elephant, rhinoceros, hippopotamus {pachyderm}.
five-toes, trunk, thick skin, big ears, herbivorous {elephant}.
extinct elephant-like mammal {mammoth}.
extinct elephant-like mammal {mastodon}.
extinct elephant-like mammal {wooly mammoth}.
Manatees, dugong, and sea cows {Sirenia} are aquatic herbivores. Forelimbs are fins. They have no hind limbs.
cetaceous, tusks, flat tail, aquatic, herbivorous {dugong} (Halicore dugong).
plant eater, aquatic, Florida and Caribbean or West Africa, paddle front flippers, flat tail {manatee} (Trichechus).
dugong or manatee {sea cow}.
Edentates {edentate} (Edentata) have few or no teeth, eat insects, and include sloth, anteater, and armadillo.
burrowing, south Africa, stocky body, hair, large ears, long snout {aardvark} (Orycteropus afer) (Orycteropodidae) (Tubulidentata).
south Africa and Asia, horny scales, long snout {anteater} {giant anteater}.
burrowing, nocturnal, horny shell, omnivorous {armadillo} (Dasypodidae).
Asia and Africa Pholidota mammals {pangolin} can eat ants and termites with a sticky tongue. Pangolins have a long tail.
Tree sloths or three-toed sloths {sloth, mammal} have long claws and hang upside down from tree branches.
Bats {bat, mammal} (Chiroptera) can fly and glide. One-fifth of mammal species are bats.
anatomy
Bats have skin from long fingers to body and legs. They have elongated forearms and fingers, with short thumb. They have heel bone {calcar} to hold wing skin. Bats have long stylohyal bone from skull base to hyoid in throat and voice box. Bats have bulbous malleus.
location
Bats are everywhere except Antarctica.
size
Smallest is five centimeters, and largest is two meters.
food
Bats eat fruit, eat insects, eat meat, and suck nectar. Vampire bats lick blood.
echolocation
Bats use echoes from ultrasound-producing vocal chords to find and recognize objects by echolocation. All bats have echolocation, except Old World fruit bats, such as flying fox, which lost it.
Fruit bats and vampire bats send one frequency. Most bats vary sound frequency. They typically use downward sound, because echoes from nearby objects have lower frequency than from farther objects. Acuity is greatest for small frequency range. Bats adjust sent-signal frequency, so echoes are in that small frequency range. Most bats make sound pulses. Some bats use slow emission rate until they get close to something. Some bats protect ears during sound emission. Some bats can calculate approach speed using Doppler shift.
types
Bats are Old World (Desmodontidae) or New World bats.
types: Old World
Old World fruit bats, horseshoe bats, Old World leaf-nosed bats, false vampire bats, bumblebee bats, and mouse-tailed bats are Old World bats. Old World fruit bats are flying foxes.
types: New World
Slit-faced bats and sheath-tailed bats are group of New World bats.
New World leaf-nosed bats, leaf-chinned bats, fishing bats, smoky bats, disk-winged bats, New Zealand short-tailed bats, and sucker-footed bats are group of New World bats.
Evening bats, long-fingered bats, free-tailed bats, and funnel-eared bats are group of New World bats.
evolution
Bats are early Laurasiatheria. Bats flew before they could echolocate.
large, fruit eater {fruit bat} (Desmodontidae).
tropical, Americas, biting, blood drinker {vampire bat} (Desmodontidae).
Carnivores {carnivore, animal}| (Carnivora) have long, sharp-pointed canine teeth.
cats
Cats include lion, tiger, leopard, cheetah, cougar or mountain lion, and jaguar.
dogs
Dogs include hyena, wolf, and fox.
seals
Sea lion, seal or fur seal, and walrus live in arctic seas. Sea otter eats sea urchins and abalone.
other
Other carnivores are bear, otter, mink, weasel, and skunk.
white color
Transparency causes white-furred animals to look white.
large, claws, carnivorous, brown/black/white {bear, animal}.
large bear {black bear}.
bear {bruin}.
large bear {grizzly bear}.
Large bears {panda} can have white fur and black eye areas.
large white bear {polar bear}.
North America, lynx, spotted, red-brown, ear tufts, short tail {bobcat} (Lynx rufus).
mountain lion {catamount}.
large, fast {cheetah}.
large, tawny {cougar}.
cat {feline}.
large, tawny {jaguar}.
large, tawny with black spots {leopard}.
large, tawny {lion}. Males have manes.
medium size {lynx}.
medium size, tawny {mountain lion}.
small, nocturnal, Central America and South America, dark spots, brown {ocelot}.
large, tawny or black {panther}.
medium size, tawny {puma}.
large, extinct in late Tertiary, long upper canine teeth {saber-toothed tiger} {sabre-toothed tiger}.
large, white {snow leopard}.
large, tawny or white {tiger, mammal}.
cat-sized wild cat {wildcat, cat}.
fluffy {Maltese cat}.
short hair, no tail {manx cat}.
long white fur {Persian cat}.
short fur {Siamese cat}.
fluffy house cat {tabby cat}.
Civet family (Viverridae) has civet, genet, fossa, and binturong. Civets {viverrine} are small and cat-like.
raccoon-like, omnivore, Mexico and southwest USA, long bushy tail with black and white rings, nocturnal, musk {bassarisk} {civet cat}.
Asian viverrine, carnivorous {mongoose} (Herpestes).
Dogs {dog, animal} can understand 65 words or phrases and 25 signals or gestures. Dogs have 25 vocalizations and 305 different gestures but have no syntax or grammar.
Dog-like animals {canine, dog} (Canidae) have pointed conical teeth.
thick fur, arctic, brown in summer and white in winter {arctic fox}.
small wolf, west USA {coyote} (Canis latrans).
carnivorous, pointed muzzle, pointed ears, bushy tail {fox, mammal}.
dog-like, nocturnal, Africa and south Asia, eats carrion {hyena} (Crocuta) (Hyaenidae).
wild, medium size, scavenger {jackal} (Canis).
gray wolf {lobo}.
large, gray, forest, north North America {timber wolf} {timberwolf}.
northern, carnivorous, large, dog-like {wolf} {gray wolf} (Canis lupus).
large {Afghan, dog}.
large {Airedale}.
medium size {basset hound}.
medium size {beagle}.
large {bloodhound}.
large, sleek {borzoi}.
medium size {boxer}.
medium size {bulldog}.
small, thin {chihuahua}.
medium size {Cocker spaniel}.
large {collie}.
medium size {dachshund}.
large, spotted {dalmatian}.
large {Doberman}.
large {German shepherd}.
large {golden retriever}.
large {Great Dane}.
large {greyhound} {grayhound}.
large {Irish setter}.
large {Labrador retriever}.
large {mastiff}.
small {Pekinese}.
large {police dog}.
small {Pomeranian}.
medium size {poodle}.
large {retriever}.
large, sleek {saluki}.
large {Samoyed, dog}.
medium size {schnauzer}.
medium size {Scottish terrier}.
large {setter}.
large {sheep dog}.
medium size {Skye terrier}.
medium size {spaniel}.
Pomeranian or Samoyed {spitz}.
large {St. Bernard}.
medium size {terrier}.
ferret, mink, otter, raccoon, skunk, weasel, and wolverine {mustelid} (Mustela).
burrowing, claws {badger, mammal}.
Northern weasels {ermine} (Mustela erminea) can have black tail tips and dark brown fur in summer and white fur in winter.
weasel, North America {ferret, mammal} (Mustela nigripes).
slender, weasel-like, arboreal, larger than weasel {marten}.
small, short-legged weasel {mink}.
freshwater, web feet, claws {otter}.
skunk {polecat}.
North America, nocturnal {raccoon} (Procyon lotor).
north Europe and Asia, soft dark fur {sable, mammal} (Martes zibellina).
marine otter {sea otter}.
medium size, New World, bushy tail, black fur, white lengthwise stripes {skunk} (Mephitis).
small, short legs, long body, long neck, brown {weasel}.
burrowing, northern forest {wolverine} (Gulo gulo).
Sea lion, seal, and walrus {pinniped} have backward hind limbs.
swimmer and diver, marine, hind limbs turned backward {seal}.
north Atlantic Ocean, earless, seal, overhanging snout {elephant seal} (Mirounga angustirostris).
large ear, marine, seal, long neck, long limbs {sea lion} (Zalophus californianus).
northern, marine, ivory tusk, tough hide, thick blubber {walrus}.
Dolphins (Sotalia) (Delphinus) (Tursiops) and whales {Cetacea} live in ocean and have blubber.
limbs
Forelimbs are fin-like. They have no hind limbs.
respiration
Cetaceans have one or two blowholes on head top.
teeth or baleen
Some Cetacea (Odontocetes) have teeth: sperm, pilot, and beluga whales, and dolphins and porpoises. Some Cetacea (Mysticetes) have baleen: blue and fin whales. Extinct ancestors belong to Archaeocetes.
whales
Sulfur-bottom whale is 150 tons and 35 meters long. Narwhal has long horn. Humpback whale, finback whale, gray whale, and blue whale are other whales.
dolphins
Dolphin has directional sonar, useful up to mile. Porpoise is like dolphin. Orca or killer whale is large dolphin. Dolphins shed soft flaky skin every two hours.
evolution
Cetacea evolved from artiodactyls.
smooth skin, pointed snout, tail flips up and down, makes sounds {dolphin} (Tursiops) (Delphinidae).
rounded forehead, beak, north Atlantic and Mediterranean {bottle-nosed dolphin} (Tursiops).
black and white, largest dolphin {orca} {killer whale}.
smaller than dolphin, blunt snout {porpoise} (Phocaena) (Lagenorhynchus).
Whales {whale, mammal} are baleen or toothed whales.
whale {leviathan}.
small, Arctic whale, male {narwhal} (Monodon monoceros). Male has large long twisted elongated tooth.
largest toothed whale {sperm whale}. Head cavity contains spermaceti and oil.
marine, large, two blowholes, filter feeder {baleen whale} (Mysticeti). Rorqual whales are finback whale, blue whale, and humpback whale. Other whales are gray whale, right whale, and Sei whale. Elastic, horny material makes fringed plates {baleen} {whalebone} down from upper jaws.
baleen whale, arctic {right whale}.
Large marine filter-feeder baleen whales {rorqual whale} include finback whale, blue whale, and humpback whale.
large, baleen whale, rorqual whale {blue whale}.
baleen whale, large, flat head, throat furrows, rorqual whale {finback whale}.
baleen whale, rorqual whale {humpback whale}.
Simple hooved mammals {simple hooved mammal} (Artiodactyla) have hooves with even number of digits. They are herbivores. They include camel, hippopotamus, whales, cow, sheep, pig, giraffe, deer, wildebeest, antelope, and bighorn sheep. They include ruminants. Hippos evolved from swamp-dwelling anthracotheres. Artiodactyla have hooves and were formerly in Ungulata order.
Artiodactyla and Perissodactyla have hooves and formerly were an order {ungulate}| (Ungulata).
Ferungulates {ferungulate} are simple hooved mammals like cow and whale, hooved mammals like horse and rhinoceros, and carnivores like cats and seals.
Mammals {ruminant} (Ruminantia) can have stomachs with four parts and chew regurgitated cud. They have hooves with even-numbered toes. Males have horns. They include cows, sheep, goats, deer, and giraffes.
deer, elk, moose, reindeer, and caribou {cervid}| (Cervidae).
cow, buffalo, sheep, goat, and antelope {bovid}| (Bovidae).
Africa, ruminant, long neck, long legs, tan with brown spots {giraffe} (Giraffa camelopardalis) (Giraffidae).
very large, thick skin, herbivorous, river, tropical Africa {hippopotamus} (Hippopotamus amphibius) (Hippopotamidae).
brown or gray, two-toe hooves, unbranched horns, fast, Africa and Asia {antelope}.
African antelope {eland}.
small, antelope, Africa and Asia, spiral horns, large eyes {gazelle}.
large, Africa, antelope, horns, long tufted tail {gnu}.
America {pronghorn antelope}.
South Africa, gazelle, springs {springbok}.
gnu {wildebeest}.
one or two humps, long neck, ruminant, Asia {camel, animal} (Camelus).
llama {alpaca llama}.
two humps, central Asia {Bactrian camel}.
single hump, large, even-toed, ungulate {dromedary camel} (Camelus).
small camel-like mammal {llama, animal} (Lama) (Camelidae).
domesticated cattle {cow, animal} (Bovidae).
baby cow {calf, cow}.
cow being herded {dogie}.
young cow {heifer}.
milk cow {milch cow}.
male cattle {steer}.
domesticated, meat {Aberdeen Angus cattle}.
buffalo {bison}.
large-shouldered bull for bull riding {Brahma bull}.
large, shaggy, brown, bison, North American plains {buffalo, mammal} (Bison bison).
domesticated, milk {Guernsey cow}.
domesticated {Hereford cattle}.
domesticated, milk {Jersey cow}.
domesticated, meat {longhorn cattle}.
arctic, bovid, thick coat {musk-ox}. It is not an ox.
Asian buffalo, typically domesticated draft animal {water buffalo, animal} (Bubalus bubalis).
adult castrated bull {ox} (Bos), or cattle-family draft animal.
large ox, shaggy hair, ox, central Asian mountains {yak, mammal} (Bos grunniens).
Asian and east African ox {zebu} can have a large hump and loose dewlap hanging under throat and neck.
Deer {deer, animal} are similar to Bovidae, but male has solid deciduous horns {antler}.
male deer {buck}.
female deer {doe}.
North America, arctic, same as reindeer {caribou}. Both sexes have large antlers.
largest deer, north Europe, broad antlers on bulls, same as moose {elk}.
male deer or male red deer over five years old {hart}.
female red deer {hind}.
largest deer, north America and Canada, broad antlers on bulls, same as elk {moose} (Alces alces).
Europe and Asia, arctic, same as caribou {reindeer}. Both sexes have large antlers.
adult male deer {stag, mammal}.
large, North America, large and branched antlers {wapiti}.
ruminant, beard, straight horns, related to sheep {goat, animal}.
goat {Angora goat}.
male goat {billy goat}.
large, ridged, curved-over horns {ibex}.
young goat {kid}.
female goat {nanny goat}.
short legs, cloven hooves, bristly hair, cartilaginous snout {pig, animal} (Suidae).
young pig {shoat}.
female pig {sow}.
pig {swine}.
wild pig, narrow body, tusks, snout bristles {boar}.
pig {hog}.
Africa, face warts, large tusks {warthog}.
boar {wild boar}.
wool, horns, ruminant, related to goat {sheep}.
female sheep {ewe}.
young sheep {lamb, mammal}.
male sheep {ram}.
north Africa {aoudad} {Barbary sheep}.
light color, large curled horns, Canadian mountains {bighorn sheep}.
Hooved mammals {hooved mammal} (Perissodactyla) have hooves with odd number of digits, are herbivores, and include horse, zebra, tapir, and rhinoceros.
very large, herbivorous, ungulate, southeast Asia and Africa, thick skin, one or two snout horns {rhinoceros} (Rhinocerotidae).
herbivorous, related to rhinoceros, large, nocturnal, ungulate, tropical {tapir}.
solid hoof, herbivorous, short hair, mane, long tail {horse} (Equus caballus) (Equidae).
horse used in war {charger}.
young horse {colt}.
horse used for racing {courser}.
farm horse {dobbin}.
horse used to pull load {draft horse}.
young female horse {filly}.
first-year horse {foal}.
emasculated horse {gelding}.
female horse {mare}.
horse used for riding {mount, horse}.
old horse {nag}.
Horse with large brown patches or black and white patches {pinto} {paint, horse}.
small horse {pony, horse}.
riding horse {saddle horse}.
male horse {stallion}.
horse used for riding {steed}.
strong horse {wheelhorse}.
first-year horse {yearling}.
medium size, various colors {appaloosa horse}.
large {Arabian horse}.
small horse-like mammal, donkey or wild ass {ass, horse-like}.
small donkey {burro}.
large horse used to pull wagons {clydesdale}.
domesticated ass {donkey} (Equus asinus).
female-horse and male-donkey sterile son or daughter {mule, mammal}.
small feral horse, North American west {mustang}.
gold, white mane, white tail {palomino}.
small, stocky, short head, small muzzle, gold, white mane, white tail {quarter horse}.
small horse {Shetland pony}.
horse-like, Africa, black and white vertical stripes {zebra}.
Burrowing domesticated rodents {rabbit} (Leporidae) can have long ears and short tails.
European rabbit {coney}.
rabbit {cottontail}.
long ear, larger than rabbit, divided upper lip, long hind legs {hare} (Lepus).
large hare, west North America {jackrabbit}.
northern hare {snowshoe hare}.
Rodents {rodent, animal}| (Rodentia) have sharp, chisel-like incisor teeth. They include squirrel, chipmunk, beaver, rat, mouse, porcupine, hamster, guinea pig, and chinchilla.
large, aquatic, thick brown fur, webbed hind feet, flat tail {beaver} (Castor).
squirrel-like, South American mountains, silver-gray fur {chinchilla} (Chinchilla laniger).
small, striped, ground, squirrel {chipmunk} (Tamias) (Eutamias).
small, Asian, burrowing, desert, long fur, light color, long hind legs {gerbil} (Gerbillus).
burrowing, small, short tail, furry cheek pouches {gopher}.
woodchuck {ground hog}.
small, short ears, no tail {guinea pig, animal} (Cavia).
small, Europe and Asia, large cheek pouches, short tail {hamster} (Mesocricetus auratus) (Cricetinae).
large, insectivore, sharp erectile bristles {hedgehog} (Erinaceidae).
small, short tail, furry, moves in group {lemming} (Lemmus).
coarse fur, burrowing, short legs, small ears, short bushy tail, thick body {marmot} (Marmota).
eusocial, tropical {mole-rat} (Bathyergidae).
small size, long hard tail {mouse, mammal}.
large, flat scaly tail, aquatic {muskrat}.
small, North America, nest filled with small items {pack rat} (Neotoma).
large, sharp erectile bristles {porcupine} (Erethizon dorsatum) (Erethizontidae).
North America, prairie, burrowing, squirrel, light brown, warning call, large colony {prairie dog} (Cynomys).
medium size, long hard tail {rat}.
arboreal, long bushy tail {squirrel} (Sciurus).
red-brown, burrowing, north and east North America, short legs, thick body, marmot {groundhog} {woodchuck} (Marmota monax).
150 million years ago to 100 million years ago, mammals {insectivore}| (Insectivora) evolved that ate insects. Early ones {primitive insectivores} look like tree shrews.
vision
Insectivores have forward vision, with eyes facing front rather than on side, allowing stereoscopic vision and space for larger frontal lobes.
hand
Insectivores have grasping hands, with opposing thumb across from fingers, for more eye-hand coordination and precise hand and arm movements.
evolution
Primitive insectivores evolved from placental mammals. Primates evolved from primitive insectivores.
types
Insectivores include mole, hedgehog, and shrew.
Mammals {mole, mammal} (Phacoschoerus) (Talpidae) (Chrysochloridae) can live underground, be nocturnal, and have front digging paws. Star-nosed moles have quickly moving touch organ in front. 22 arms have 25,000 Eimer's organs, which are similar to Pacinian corpuscles and contain touch receptors. Free-nerve-ending touch receptors are for vibration and contact. Merkel-cell touch receptors are for pressure. Both are in all mammals. Moles have free nerve endings in a circle, used for detecting texture. The most-sensitive arm matures first and is larger in embryos. Skin surfaces probably had such strips in mammal predecessors.
Small mouse-like mammals {shrew, primate} {tree shrew} (Soricidae) can have a long pointed snout.
Insectivore mammals {primate} include prosiminan, New World monkey, Old World monkey, ape, and human. Primates can learn new behaviors, are curious, are vigilant, have short attention span, easily distract, and have many stereotypical activities that last for long periods.
evolution
Primates arose from primitive insectivores in early Eocene, 65 million years ago.
Strepsirhines arose 60 million years ago. They include loris, lemur, and galago.
Haplorhines {anthropoid apes} arose 55 million years ago. They include tarsiers, bush babies, monkeys, apes, and humans.
Prosimians include Strepsirhines and early Haplorhines.
Haplorhine monkeys became Old World monkeys {Catarrhini} and New World monkeys {Platyrrhini} 40 million years ago. New World monkeys include spider monkeys. Old World monkeys (Cercopithecidae) include rhesus monkeys, capuchins, macaques, and baboons.
Old World monkeys and gibbons (Hylobates) separated 30 million years ago.
Gibbons and anthropoid apes (great apes) (hominids) (Hominidae) separated 17 to 19 million years ago. Anthropoid apes include Pongo pan with orangutans, Gorilla with gorillas, Pan troglodytes with chimpanzees, Pan paniscus {pygmy chimpanzee}, and Homo with humans. Note: An older classification put humans into a hominid family (Hominidae) and all hominids except humans into pongid family (Pongidae).
Orangutans began 16 million years ago.
Gorillas separated from orangutans 8 to 9 million years ago.
Chimpanzees separated from gorillas 6.2 to 6.7 million years ago.
A family (hominins) (Homininae) with genuses Australopithecus, Paranthropus, Ardipithecus, and Homo began 6 million years ago.
Genus Homo began 2 million years ago.
food
Primates were predators, but some are now savanna vegetarians.
society
Primates live in territorial groups of 100 or less, with males dominating females. The six species vary greatly in social organization. Primates have long maternal care of young. All primate societies have aggressive dominance systems, scaling in behavior, socialization, matrilineal social organization, and game playing.
society: signals
Social organization depends on signaling. Primates have rudimentary vocal-signal languages. For example, gibbons have 12 standardized, meaningful calls.
hands and feet
Primates can have prehensile hands and feet. They have opposing thumb and can have opposing toe. They have nails instead of claws. They have grasping hands. They developed better hand movements and hand-eye-body coordination.
movement control
In primates, posterior parietal lobe is for movement control.
DNA transposition
Primate DNA-transposition rate is lower than mice rate.
brain
Neocortex has enlarged occipital and temporal lobes.
senses
Primates have olfactory systems similar to those in other placental mammals.
senses: vision
Primates have large eyes in front in large bony sockets. They have fovea high ganglion-cell concentration.
Optic tectums see only visual-field contralateral half, unlike other vertebrates. Primates integrate binocular input in optic tectum, laminated dorsal lateral geniculate nucleus, and primary visual cortex maps.
Primates have dorsolateral visual area (DL), adjacent to medial temporal lobe. They have fusiform gyrus on occipital-lobe underside.
Nocturnal visual predators, such as owls and cats, orient body so prey is in front and then move forward, using forelimbs and jaws to attack. Stereoscopic vision detects prey distance and discriminates camouflaged prey from background.
Primates have lateral prefrontal cortex {lateral prefrontal cortex}, but lower mammals do not.
Strepsirhines have furless, moist, mucous tissue {rhinarium, primate} with cleft down middle between upper lip and nostrils, as in most mammals.
Alu repeats {DNA repeat, primate} are only in primates, repeat million times in different locations, are 10% of DNA, have internal promoter, and are similar in sequence to ribosome gene.
Prosimians {prosimian}| include tarsiers, bush babies, lorises, lemurs, and galagos. They are small, live in fine-branch niches, eat fruit and/or insects, have short muzzles and short noses, have fingernails, have large and widely spaced eyes, and have more than 32 teeth.
smell
They have scent glands, like most primitive mammals, and use scent-marking behaviors for social communication.
vision
Optic tectums receive only from visual-field left or right half, whereas in lower mammals optic tectums receive from left and right.
evolution
Prosimians developed from primitive insectivores.
First primate family {Strepsirhines} includes lorises, lemurs, and galagos but not bush babies or tarsiers. They have furless, moist, mucous tissue with cleft down middle between upper lip and nostrils {rhinarium, Strepsirhines}, as in most mammals. They have simple social organization. In Strepsirhines and primitive mammals, main input to amygdala is from olfactory bulb.
Second primate family {Haplorhines} includes tarsiers, monkeys, apes, and humans. It has furry rhinarium {rhinarium, Haplorhines} and movable upper lip for facial expressions. It uses gestures and has complex social organization. In Haplorhines, main input to amygdala is from visual inferotemporal cortex.
moist nose {bush baby}.
Madagascar, arboreal, mostly nocturnal {lemur} (Lemuridae).
nocturnal, Indonesia, dry nose {tarsier}.
Monkeys {monkey} include New World monkeys and Old World monkeys. Monkeys evolved from prosimians. First monkeys were like New World monkeys.
ape or monkey {simian}.
Smaller monkeys are diurnal and eat leaves {folivore}.
Monkeys can be larger, be active day and night, and eat fruit {frugivore}|. Primate frugivores have larger brains with more neocortex than same-size primate folivores. Fruit supply and type always varies, because different plants bear fruit at different times and locations in tropical forest. Frugivores require better visual perception and memory.
Marmosets, tamarins, squirrel monkeys, and spider monkeys {New World monkey}| were first monkeys.
evolution
New World monkeys came from Africa to South America on floating vegetation. Parapithecus was ancestor of Old World monkeys.
habitat
New World monkeys live in trees.
anatomy: tail
New World monkeys have prehensile tails.
anatomy: nostrils
New World monkeys have upward-pointing nostrils (Platyrrhini) and broad flat noses.
brain: striate cortex
Primate striate cortex can differ from motor cortex {giant Betz cell} in laminar organization, cell number, cell types, and general connectivity patterns.
brain: ventral premotor area
Ventral premotor area aids visually guided hand movements and learning by watching.
brain: Wernicke's area
Monkeys have Wernicke's area at vision, audition, and somaesthetic cortical junction.
senses
In monkeys, object perception uses one sense pathway involving all senses. Humans use this pathway only at birth.
senses: vision
Fovea allows sharp vision in visual-field center. Brain pathway for shapes and brain pathway for movement and contrast evolved. Brain area V1 has blobs and interblobs. V4, V8, and MT brain areas evolved.
self
Tamarin monkeys are curious about their bodies and movements they see in mirrors, unlike cats and dogs. Monkeys can have sense of self [Hauser, 2000].
mother
Monkeys normally cling to mothers for contact and security. If mother was absent from monkey infants, infants stayed afraid of strange objects and did not explore them. Later, the monkeys had sexual and mothering problems. If monkeys have no play and no mother, they have more aggression and wariness. Baby monkeys cling to cloth monkeys as mother substitutes [Harlow and Harlow, 1949].
suffering
Monkeys can suffer, because they can do something about conditions that make them suffer [Povinelli, 1998].
signal
Vervet monkeys make different alarm calls for eagles, leopards, and snakes and use grunts in social interactions [Cheney and Seyfarth, 1990] [Seyfarth and Cheney, 1992].
Putty-nosed monkeys make alarm calls for crowned eagles that make other monkeys stand still. Calls for leopards cause them look at ground. They can combine the calls to signal group to leave place.
Marmosets, tamarins, squirrel monkeys, and spider monkeys live in trees {arboreal}| and have prehensile tails.
Small monkeys {marmoset} have soft fur, come from South America and Central America, and have claws instead of nails.
monkey {rhesus monkey}.
monkey {spider monkey}.
monkey {squirrel monkey}.
African monkeys {Old World monkey} include capuchin, macaque, baboon, and mandrill. Macaques include rhesus monkeys (Macaca mulatta) and crab-eating monkeys (Macaca fascicularis). Old World monkeys are arboreal.
nostrils
Old World monkeys (Cercopithecidae) have down-pointing nostrils and short narrow noses (Catarrhini), allowing better vision and more space for frontal lobes.
sitting pads
Old World monkeys sit upright on sometimes colored buttock sitting pads.
tailless
Old World monkeys have no prehensile tails.
reproduction
Old World monkeys have sexual dimorphism and male rivalry.
digestion
Old World monkeys ate fruit and had 32 teeth.
senses
Short narrow noses had nose openings pointed down (Catarrhini), for better vision and more space available for frontal lobes. They had three cone types and full color vision. Postorbital septum isolated eyes from temporal muscles.
evolution
Old World monkeys differentiated from New World monkeys in Oligocene epoch.
types
Xenopithecus was ancient Old World Monkey. Aegyptopithecus was Old-World monkey in Fayum deposits in Egypt.
Apes {ape, animal} came from Old World monkeys.
cognition: causation
Apes understand that acting on one object can cause connected-object motion.
cognition: deception
Apes practice deception by distracting attention, so they can steal food or mates [Byrne and Whiten, 1988] [Whiten and Byrne, 1997].
cognition: laughing
Only humans laugh, but young chimpanzees puff air when they play, similar to laughing. Apes can also appear happy. Chimpanzees smile when submitting, but not from happiness. Perhaps, laughter is for alliance making.
cognition: mirror
Some apes can touch body spots they see in mirrors. Some apes seem to recognize themselves in mirrors after a while. Chimpanzees, orangutans, bonobos, and humans over two years old can use their reflections in mirrors to perceive body and direct actions. They can recognize themselves and have sense of self. Gorillas, monkeys, and children less than two years old do not [Gallup, 1970] [Gallup, 1998]. Chimps, bonobos, and orangutans can recognize themselves in mirrors immediately or after several-days experience, but gorillas, baboons, and most other primates cannot [Napier, 1976] [Napier, 1977].
cognition: play
Apes like to play.
cognition: self
Chimpanzees have no sense of self and no consciousness of mental states, though they can inspect their bodies using mirrors [Heyes and Galef, 1996] [Heyes, 1998].
cognition: suffering
Apes can suffer, because they can do something about conditions that make them suffer.
biology: parental care
Apes have parental care over long childhoods.
biology: palm walking
Apes used palm walking, not knuckle walking as in monkeys.
biology: reflex
Adult apes have Babiniski reflex, to grasp tree branches with toes.
biology: one sense pathway
In apes, object perception uses one sense pathway involving all senses, as humans do at birth.
biology: pheromone and sex
Sex-hormone-derived pheromones are in skin secretions [Savic et al., 2001] [Savic, 2002] [Sobel et al., 1999].
biology: pheromone receptivity
Baboons secrete female pheromones during receptivity. Community living can synchronize ovulation through olfactory signal. Small pheromone amounts work [Gangestad et al., 2002] [McClintock, 1998] [Schank, 2001] [Stern and McClintock, 1998] [Weller et al., 1999] [Pantages and Dulac, 2000].
biology: serotonin reuptake
Anthropoid apes have different promoter sequence for serotonin reuptake transport gene than humans do.
biology: evolution
Proconsul was lesser ape and was hominid ancestor. It was ape-like in shoulder, elbow, cranium, and teeth dentition. It was monkey-like in long trunk, backbone, pelvis, arm, and hand. At least four species weighed from 10 to 80 kilograms.
communication: sign language
After four years of training, the chimpanzee Washoe acquired over 100 American Sign Language signs. It heard no other language. Some signs were for general classes, rather than just objects and events. Some signs changed or extended. Washoe used sign order. Washoe substituted signs with similar meanings or shapes.
However, no primates develop signing themselves. Humans have to teach them. Humans cue chimpanzees to make signs, and chimpanzees sign to get rewards. Chimpanzees sign to each other socially but not for rewards [Gardner and Gardner, 1969].
communication: signals
Chimpanzees and gorillas cannot learn to use expressions with interruptions. Animal communications always repeat. Behavior, display, or signal redundancy and ritualization increase communication efficiency. Animals often use opposite signals, such as high and low, or loud and soft, for opposite intentions or behavior. Animals can modify signals in different contexts, but they do not rearrange symbol order deliberately nor assign meaning to signal order.
communication: symbol
Apes have 150 to 200 non-linguistic symbols, such as facial expressions, danger and location calls, courtship rituals and displays, grooming, group or family signals, and personal communication between individuals. Humans have 150 to 200 non-linguistic symbols.
communication: word
The bonobo Kanzi used and understood 150 words, typically to express desires or refer to present objects. Learning was instrumental association, with no grammar. Perhaps, it was not referential [Savage-Rumbaugh, 1986].
society
Ape societies have 10 to 100 animals.
Human ancestors {missing link}| can fill fossil gap between apes and humans.
Male orangutans have cheek pads {flanges}.
Australopithecus were not always robust {gracile}|.
Dryopithecus had face that tilted down {klinorhynchy, face}. Orangutans, gibbons, and siamangs have airorhynchy.
Orangutans, gibbons, and siamangs have faces that tilt up {airorhynchy, face}. Dryopithecus had klinorhynchy.
Lesser apes {ape, lesser} {lesser ape} {pongid}| {hylobatid} (Hylobates) separated from Old World monkeys [-22000000]. Proconsul in Kenya, Afropithecus in Kenya, Kenyapithecus in Kenya, and Morotopithecus in Uganda lived in early Miocene. Early lesser apes were like siamang and gibbon, except they walked on all fours on branch tops. Apes have broad chests and large brains. They weigh from 3 to 80 kilograms.
development
Apes grow more slowly than monkeys.
reproduction
Apes reproduced less than monkeys.
skeleton
Apes have more flexible hips, shoulders, wrists, ankles, hands, and feet than monkeys.
digestion
Some apes eat leaves. Some apes eat fruit and nuts.
tailless
Having no tail allows sitting, more sexual intercourse positions, and new spinal shapes.
posture
Apes have semi-erect posture. Apes can hold arms above heads and so hang, using opposing thumbs.
face
Apes have movable upper lips, allowing facial expressions.
ape, small, arboreal, muzzle, southeast Asia and East Indies, long arms {gibbon} (Hylobates).
ape, large, black, terrestrial, bare colored buttocks, Africa and Asia {baboon} (Papio) (Cercopithecidae).
west Africa baboon {mandrill}.
Apes {great ape} evolved.
skeleton
Great apes have shoulder blades on back, while lesser apes have shoulder blades on sides. Great apes have shallow ribcages, while lesser apes have deep ribcages. Great apes have flexible hips, while lesser apes have restricted movement.
skeleton: spine
Great apes have short stiff S-shaped spines with two curves, rather than straight or single-curve spines, for more upright posture. S-shaped spine is more flexible, allows running, and aids balance. Great-ape vertebrae projections point out back, while lesser-ape vertebrae projections point to side.
arm
Great apes have big hands, while lesser apes have small hands. Great apes can make rapid arm movements similar to hammering, clubbing, and throwing. Great apes can extend elbow joint fully, while lesser apes cannot make arm straight. Great apes have arms longer than legs, while lesser apes have equal lengths.
tools
Great apes make and use tools.
hunting
Great apes hunt, but not with tools.
society
Great apes live in societies, which increase opportunities for learning, experience, and knowledge.
senses
Great apes do not correlate senses.
evolution
Apes and great apes split 15 million years ago. Great apes evolved from Proconsul-like lesser apes.
Pongo pygmaeus {orangutan} are great apes, are solitary, have no tail, live in trees in nest, and are in Borneo and Sumatra rain forests. They are safe in treetops. They can live for 60 years.
sex
Males become mature at 12 to 14 years, are twice as big as females, have flanges, have throat sac for yelling {long call}, and have long orange hair. Puberty is at age 7 to 9. If group has dominant male, young males can stay pubescent.
tools
In swamp forests of Sumatra and Borneo, where food is abundant, they can learn to use tools at 7 years old.
Anthropoid apes {anthropoid ape} (hominids), such as gorillas and chimpanzees, differentiated from apes in hands, feet, arms, and legs.
types
Propliopithecus was first anthropoid ape and direct ancestor of all hominids.
hand
Anthropoid apes have grasping hands.
walking
Anthropoid apes walk upright, requiring mechanisms for balance, allowing farther and greater lateral vision, and requiring learned gait. Anthropoid apes have wider territory and shared or secured territory.
habitat
Gorillas live on ground, and others live in trees.
communication
Anthropoid apes communicate, using dozens of meaningful sounds, about objects but do not have mental states.
vision
Color vision can see ripe fruits in forest and recognize faces.
brain
Delay system in frontal lobe between senses and motor nerves possibly allows decision-making. Anthropoid apes are curious, reason, have emotions, have social instincts, and imitate. Great apes have neurons in anterior cingulate that have apical dendrite and dendrite near axon and look like spindles.
largest anthropoid ape, black, terrestrial, vegetarian, equatorial West Africa {gorilla} (Gorilla gorilla).
Genus Pan apes {Pan, ape} split from gorillas and was like chimpanzee, pygmy chimpanzee, or bonobo. Pan apes weigh 30 to 60 kilograms. They eat fruit and have large canine teeth with thin enamel. They have long arms and legs. They are arboreal. They are knuckle walkers on all fours. They are sexually dimorphic and have polygynous social structure. They are hairy.
pygmy chimpanzee {bonobo}|.
Chimpanzees {chimpanzee} are great apes. Chimpanzees can communicate using complex sign or symbol systems and have more than 30 meaningful vocalizations. Chimpanzees can cooperate. Chimpanzees can deceive others. Chimpanzees have concept of self. Chimpanzees use and make tools. Given puzzles, they manipulate pieces, even without reward.
Hominins {hominin}| (Homininae) vary from anthropoid apes (great apes) (hominids) (Hominidae) in locomotion, hands, tools, sight, sociability, and language.
evolution
Hominins differentiated from Pan ancestors six million years ago.
habitat
Australopithecus lived in savannas, rather than forests, and used more animal food than apes. Perhaps, necessity to eat seeds and nuts aided hand evolution. Hominins developed environments, with more energy available for brain maintenance. Free-ranging energetic environments and multiply skilled bodies allowed energy-intensive cortex to vary, grow, and integrate senses.
anatomy: tailless
Hominins had no tail, allowing more variations in intercourse position, sitting, and spinal shape.
anatomy: face
Hominins have nosebridges and nose tips, jutting chins, short canine teeth, and lips with median furrow that rolls outward.
anatomy: arm
Hominins have shorter arms than great apes and throw accurately.
anatomy: foot
Hominins have feet that arch across and lengthwise. They do not have opposed big toes.
anatomy: hair
Hominins are relatively hairless.
anatomy: posture
Hominins have erect posture.
reproduction
Hominins mature sexually earlier than other great apes, as measured by teeth eruption.
senses
Sense integration allows tracking individuals that are not present, mapping environments, and remembering.
nervous system
Brains were two to three times bigger than great-ape brains.
communication
Hominins blend the dozen meaningful ape sounds to produce new sounds related to objects far away in time or place. They possibly use nouns, verbs, and modifiers with simple syntax. They recall memories.
communication: larynx
Larynx became lower and opened throat space {supralaryngeal space}, which allows more speech sounds.
Varied and separated habitats isolated four hominin species {Australopithecus} {australopithecenes}: first Australopithecus afarensis, then gracile Australopithecus africanus, robust Australopithecus robustus, and robust Australopithecus boisei.
habitat
Australopithecus lived on ground in woodlands and savannas. Perhaps, it slept in trees or cliffs.
digestion
Australopithecus ate vegetables and later meat and had ape-like dentition.
behavior
Australopithecus foraged.
tools
Australopithecus used pumice flakes and stone choppers as rooting tools.
arm
Australopithecus had large hands, long fingers, and short arms.
walking
Australopithecus was bipedal, had short stride, ran slowly, and had no knuckle walking.
development
Maturation time was short.
brain
Brain was one-third modern human size.
Early hominins {Australopithecus afarensis} were gracile, weighed 35 kilograms, and were one meter tall.
evolution
Australopithecus afarensis came from Australopithecus anamensis and was Australopithecus-gahri ancestor.
tools
Australopithecus afarensis used pebble tools.
climbing
Australopithecus afarensis had climbing adaptations in fingers, hands, wrists, elbows, and shoulders, with long arms and short legs.
walking
Australopithecus afarensis was bipedal with full striding gait, putting body weight over one leg while other leg moved. It had arched feet and non-opposable big toes, like modern human feet. It had knee valgus angle. It had great pelvic width. Perhaps, width was for pelvic rotation in walking. It had short, broad, backward, extended, iliac blades.
hand
Australopithecus afarensis had shorter thumbs.
society
Perhaps, Australopithecus afarensis had large kin-related and many-male groups, with some non-kin females.
digestion
Australopithecus afarensis had large and flat cheek teeth, suggesting fruit and leaf diet.
face
Australopithecus afarensis had big faces.
brain
Australopithecus afarensis had 400-cc brains, with 3.1 encephalization quotient. It had forward-placed and downward-directed foramen magnum, indicating head was upright on spine. Bipedalism led to an enlarged occipital-marginal-sinus system, which forced new blood hydrostatic pressures on vertebral venous plexus.
Second Australopithecus {Australopithecus africanus} [first found 1924] was gracile, weighed 35 kilograms, and was four feet tall.
evolution
Australopithecus africanus came from Australopithecus anamensis and was Australopithecus-robustus ancestor.
habitat
Australopithecus africanus lived in grasslands, not forests, and probably lived in one place for long periods. Perhaps, it used windbreaks.
hunting
Australopithecus africanus hunted animals, ate raw meat, cut skins, smashed bones, and took meat home.
tools
Australopithecus africanus selected stones, carried them home, and chipped to make hand-held choppers.
hand
Australopithecus africanus had flattened fingertips.
spine
S-shaped spines, with two curves, allowed more back flexibility and so more upright walking, more erect posture, faster running, and better balance. Upright posture allowed wider and farther vision.
digestion
Australopithecus africanus had no canine teeth and lean jaws, like humans, reflecting different diet.
brain
Australopithecus africanus had low skulls, with 500-cc to 800-cc brains. Many anastomotic channels with emissary veins near foramen magnum take blood to vertebral venous plexus. Perhaps, expanded neocortex frontal lobes allowed improved memory, spatial orientation, temporal orientation, and multisensory abilities.
Paranthropus hominins {Australopithecus robustus} (Paranthropus robustus) were not on human line, were 45 kilograms, were heavyset, and were vegetarian. Paranthropus robustus came from Australopithecus africanus. Perhaps, Australopithecus aethiopicus preceded it. Brain was 500 cc.
Paranthropus hominins {Australopithecus boisei} (Paranthropus boisei) were not on human line, were robust, weighed 50 kilograms, and lived in east Africa. Paranthropus had vegetarian diets, as shown by dentition and face. Brain was 500 cc to 530 cc.
Humans {Homo} {human} are vertebrates, mammals, and primates and share their fundamental behaviors.
evolution
Humans evolved from australopithecines. Strong sexual selection, complex social lives, changing environments, cultural effects, social contacts, increased population density, agriculture, food surpluses, and wars emphasize aggression, fitness, and intelligence. Humans evolved faster than apes. Humans evolved through pedomorphism, accounting for greater brain size, because children have relatively bigger brains.
evolution: environment
Early humans had direct competition with similar species and had predators.
development
Human life span is as expected for great apes with human size and brain.
behavior: hand
Hands have opposing thumbs and many available grips. Humans can gesture.
behavior: walking
Humans walk upright on strong legs. Upright walking requires mechanisms for balance, allows farther vision and greater lateral vision, requires learning gait, allows wider territory and means of sharing territory, and allows hand, foot, arm, and leg differentiation.
behavior: society
Humans live in organized groups. They have faces and know facial expression meaning. They perceive others' needs and desires. They know action effects on others. They react to others' behaviors and communications. They can have rapport. They can influence. They kiss.
behavior: language
Human language probably developed from graded primate vocalizations. Humans can pronounce 40 phonemes. They use voice modulation. They express feelings. Speech depends on upright posture, which allows tongue-position shifts and pharyngeal-tract lengthening. Humans use symbolic thought and language to plan and form strategies. Memories allow using and transmitting past knowledge. Humans have music.
senses
Humans use sight as dominant sense.
brain
In evolving to humans, supragranular layer became upper three cortical layers, middle layer thickened, subgranular layer divided into lower two layers, and secondary and tertiary sulci had increased associational areas.
handedness
Right-handedness first appeared in Lower Old Stone Age, when tool making became common. Starting 300,000 years ago, humans probably had cerebral dominance, because skulls are asymmetric and people inherit brain and skull shape. Human skulls mold to brains. Right-handers typically support and orient objects in left hand, without using visual feedback, and perform fine movements with right fingers, using visual feedback. Most people use right hand for gesticulation.
handedness: abilities
Performance by right-handers and left-handers is equal on all tasks. No special ability or disability distinguishes left-handers.
handedness: factors
Handedness inherits. Social pressures or early experience, especially with objects designed for right-handers, affects handedness. Brain damage before or after birth can shift cerebral dominance or prevent hemispheric specialization. Subnormal and epileptic people have more left-handedness.
handedness: anatomy
In right-handers, left cerebral hemisphere has sense and motor connections to both body sides, and right hemisphere connects to only one side. In left-handers, cerebral lateralization is less. In right-handers, left side has fewer skills, poorer timing and coordination, more variability, and more frequent and slower corrections.
handedness: ratio
Left-handers are 4% to 36% of people in different races and cultures.
handedness: mammals
Mammals besides humans show paw preferences but equally to left or right.
First humans {Homo habilis} split from Australopithecus.
size
Homo habilis was 1.35 to 1.5 meters tall and weighed 50 kilograms.
culture
Homo habilis formed Lower-Paleolithic Oldowan Culture. Perhaps, it had labor division, cooperation, and reciprocity.
culture: tools
Homo habilis chipped sharp flakes from larger stone cores. Perhaps, it carved wood tools.
digestion
Homo habilis ate plants and meat.
hunting
Perhaps, Homo habilis scavenged, hunted, and had food sharing.
body
Homo habilis had curved finger bones, long arms, short legs, and modified pelvic and leg bones.
walking
Upright walking on arched feet allowed better running, jumping, balance, and flexibility.
reproduction
No estrus in females allowed continuous sexual receptivity. Intervals between births are shorter for humans than for great apes.
skin
Few body hairs allowed skin sensitivity.
head
Homo habilis had post-orbital septum and thin brow ridges. Skull back was round.
brain
Large left-brain Broca's motor speech area indicates speech. Advanced vocal cords and brain language areas allowed better communication. Bigger frontal and parietal lobes were in 700-cc brains, with 4.0 encephalization quotient. Brain had sulci and gyrus patterns like Homo sapiens. Two more cell layers in neocortex increased processing complexity and information distribution.
senses
Homo habilis had reduced smell sense and integrated senses.
Early African Homo erectus hunter-gatherers {Homo ergaster} ate meat. Homo ergaster weighed three times more and was two times taller than Australopithecus. Homo ergaster came from Homo habilis.
Early Homo species {Homo erectus} was 1.65 meters tall.
evolution
Homo erectus came from Homo habilis and was ancestor of Homo floresiensis and archaic Homo sapiens.
anatomy: body
Homo erectus had narrow bowl-shaped pelvis and conical thorax. Homo sapiens has barrel shaped thorax.
anatomy: head
Homo erectus had heavy eyebrows, no chins, big jaws, and low skulls. Extra bone was on skull midline {sagittal keel}.
anatomy: senses
Homo erectus had sense organs like modern humans. Skull indents behind eyes, so eye sockets protrude.
anatomy: brain
Brains were 1000 cc, two-thirds of modern brains, with six-layer brain cortex, specialized right and left brain hemispheres, and association areas. Encephalization quotient was 5.5.
anatomy: teeth
Perhaps, Homo erectus gripped and tore using front teeth by prognathism.
anatomy: hand
Homo erectus held fingers to palm and had precision grips.
anatomy: arm
Homo erectus had large femoral heads like Homo sapiens.
anatomy: leg
Arched feet allowed better running and jumping, better balance, and more flexible movements. Arched feet had no grasping.
anatomy: sexual dimorphism
Male and female body sizes were more equal than in Homo habilis.
walking
Homo erectus walked fully erect.
reproduction
Homo erectus had sexual intercourse but no longer had estrus, so females were always sexually ready.
development
Babies were immature at birth, like Homo sapiens.
culture
Homo erectus had Acheulean culture of Lower Paleolithic. Groups with social organization lived in caves or later wood or bone houses and had territories. Homo erectus had birth rituals, long childhood with rites of passage to adulthood, and courtship rituals.
culture: communication
Homo erectus signaled and used simple speech. It planned for events far away in space and time. It realized world of individual things and people existed.
culture: fire
Starting 200,000 years ago, Homo erectus used fire for warming, lighting, scaring animals out of caves, hunting, hardening wood, cooking plants, cooking bones for marrow, and building community. It had specialized fire builders.
culture: tools
Homo erectus used flaked stone tools, chipped hand axes from large stone cores [-1500000], and had stone symmetrical hand axes with two sides [-750000]. Homo erectus carved wooden spears and wooden bowls.
culture: hunting
Homo erectus killed large animals, coordinated hunts, and gathered foods. Savanna had enough food to support two people per square mile. Hunting societies had one leader. Males were hunters and dominated life. Male friendship developed. Females did domestic work. Perhaps, aquatic societies lived on fish and shellfish, shared among all, had no leader, and lived near oceans or fresh water.
Homo erectus possibly used gripping and tearing by front teeth {prognathism}.
Archaic Homo sapiens {Homo heidelbergensis} came from Homo erectus. Homo heidelbergensis had larger brains, flatter faces, and smaller brow ridges. It invented prepared-core technique.
Neanderthals {Homo neanderthalensis} were strong.
evolution
Neanderthals came from archaic Homo sapiens [-700000 to -500000]. They became extinct [-35000]. They are not human ancestors, because Neanderthal mitochondrial DNA is not like Homo-sapiens mitochondrial DNA (Svante Pääbo), though genomes are 99.5 percent the same. Interbreeding among humans and Neanderthals stopped by 370,000 years ago.
posture
Neanderthals had same postures and body movements as Homo sapiens.
body
Neanderthals had barrel chests and short and large limb bones.
head
Neanderthals had reduced skull thickness, low skulls, no chins, broad noses, heavy jaws, low and sloped foreheads, and heavy arched brow ridges.
teeth
Neanderthals had human teeth, which they used as clamps or vises.
handedness
Neanderthals had handedness.
brain
Brain was 900 cc to 1100 cc, with expanded parietal lobes. Special brain language areas were on left side, with right-left brain asymmetry.
language
Neanderthals spoke. Perhaps, Neanderthal throat anatomy inhibited good speech.
walking
Neanderthals walked erect.
habitat
Neanderthals lived in caves in cold climates.
culture
Neanderthals had Upper or Late Acheulian Culture of Lower Paleolithic and Mousterian Culture of Middle Paleolithic. They had customs and laws for societies.
culture: hunting
Neanderthals were big-game hunters, used wood spears with fire-hardened points [-50000], used flint weapons, and wore animal skins.
culture: fire
Neanderthals used fire [-500000] in Zhoukoudian cave in north China and had hearths.
culture: burial
Neanderthals buried the dead [-100000].
culture: painting
Neanderthals gathered red ocher.
Advanced humans {Homo sapiens} probably began in Africa 100,000 to 200,000 years ago. African and non-African Homo sapiens then diverged.
habitat
Early Homo sapiens lived in caves.
brain
Early Homo sapiens had brains the same size as now, with 7.6 encephalization quotient. It had new associational-cortex and frontal-lobe development. It had consciousness.
culture: tools
Early Homo sapiens used chipped stone tools and built tools to make tools.
culture: language
Early Homo sapiens probably spoke and knew symbols and language.
culture: clothing
Early Homo sapiens wore clothing.
culture: fire
Homo sapiens used sustained fire [-40000].
culture: domestication
Homo sapiens domesticated plants and animals [-8000]. Homo sapiens used medicinal herbs in Iraq [-8000].
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Date Modified: 2022.0225