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126 Cards in this Set
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Phylum Arthropoda |
Largest, most diverse, most advanced protostome phylum - 80% of described animal species (1 million+) are arthropods Trilobites - fossil arthropods - abundant in fossil record: went extinct during Permian extinction Primitive insect form - wingless, no metamorphosis - silverfish: most ancient living insects |
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Arthropod Characteristics |
Segmented exoskeletons composed of chitin with pairs of jointed legs - exoskeleton serves for protection, waterproofing and muscle attachment Three tissues with reduced body cavity Nervous system - brain and ventral nerve cord; similar to Annelida Open circulatory system similar to molluscs Complete digestive system Excretory system - Malphigian tubules Sexual reproduction - sexes are separate and fertilization is internal Hormones - control metamorphosis, molting, behavior and mating in arthropods Arthropoda divided into 4 subgroups - chelicerates, crustaceans, myriapoda, insects |
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Arthropod circulatory system |
Open system similar to molluscs - elongate dorsal vessel serves as heart: pumps circulating fluid to body - fluid empties into body cavity: fluid bathes tissues directly - fluid returns to dorsal vessel and then to heart |
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Arthropod respiratory system |
Exchange O2 and CO2 Aquatic species - gills exchange with water Insects - trachea system directs air from outside into body tissues Spiders - book lungs exchange gases |
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Arthropod Excretory system |
Malphigian tubules - outgrowths of digestive tract extend into body cavity - excess wastes excreted from body cavity into digestive tract |
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Arthropod hormones |
Control metamorphosis, molting, behavior and mating - metamorphosis: change in insect form during life cycle - molting: exoskeleton is discarded and replaced as arthropod grows |
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Chelicerates |
Arachnids; spiders, scorpions, ticks, horseshoe crab. Bodies organized into cephalothorax and abdomen - no antennae, mandibles or wings - simple eye with single lens 6 pairs of appendages on cephalothorax |
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6 pairs of appendages on cephalothorax |
1st pair of appendages form chelicerae - mouth parts on midline - chelicerae masticate food and mix food with digestive enzymes * can form pincers or fangs with poison glands 2nd pair of appendages forms pedipalps - lateral to chelicerae - modified for feeding, sensory or reproduction 4 pairs of appendages function as walking legs |
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Spiders |
Chelicerates Produce silk webs - predators - spinnerets: specialized abdominal glands that secrete liquid protein fibers * fibers solidify into web when exposed to air * webs function to catch prey, escape predators, cover eggs, package food during courtship * web structure characteristic for different species groups |
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Scorpions |
Chelicerate Predators; pedipalps modified into pinchers - stinger on abdomen injects venom into prey - parental: carry babies on body |
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Ticks |
Chelicerate Blood sucking arachnids; parasitic; spread disease - transmit bacteria causing Lyme disease and Rocky Mountain spotted fever Have pores in skin for breathing Latch on to prey |
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Horseshoe crab |
Chelicerate Limulus; ancient, marine arthropod group - related to trilobites - living fossil - heavy exoskeleton - long extending tail - reproduce on land - book gills |
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Crustaceans |
Shrimp, lobsters, crabs, crayfish, pillbugs; marine and fresh water; "insects of the seas" - Cephalothorax (head, thorax) and abdomen form from jointed segments * carapace - hard calcium carbonate exoskeleton on cephalothorax - 1 pair of appendages on each segment - separate sexes: * 1st pair of swimmerets elongated in male crayfish - transfers sperm into female crayfish * no 1st swimmerets in females (lobsters/ crayfish produce swimming larvae stages) - respiratory system: gas exchange occurs across gills - complete digestive system: 2 stomachs; gastric mill grinds food |
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Crustacean appendages |
1 pair of appendages on each segment - 2 pair of antennae: only arthropod group with 2 different antennae - 3 or more pairs of appendages function as mouth parts: 3rd maxilliped are the largest - 5 pair form walking legs on thorax * 1st pair modified into claws - other pairs form swimmeret appendages on abdomen |
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Myriapods - "many footed" |
Head with antennae and mouthparts, segmented body Centipedes - carnivorous; eat insects and small vertebrates - 1 pair of walking legs on each segment * poison claws on 1st body segment Millipedes - herbivorous; eat decaying vegetation - each segment forms from 2 fused segments * 2 pair of walking legs on each segment * not considered to be closely related to centipedes |
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Insects |
Most successful, diverse and abundant animal group - more species than all other animal groups combined - became dominant during the Paleozoic: found everywhere on earth today |
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Insect body |
divided into head, thorax, and abdomen Head - 2 compound eyes, 1 pair of antennae, 3 pairs of mouthparts Thorax - composed of 3 segments with 3 pairs of walking legs - 1st pair of walking legs on each segment - 1 or 2 pairs of wings on thorax: only invertebrates that fly Abdomen - no legs on abdomen |
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Insect metamorphosis |
Incomplete metamorphosis - grasshopper, tick - nymph: immature, juvenile form; resembles adult; gradually changes into adult Complete metamorphosis - Monarch butterfly - larvae: immature juvenile form; does not resemble adult * feeding stage - larvae increases in size, forms pupa and then adult - adult: butterfly; dispersal, reproductive stage |
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Major order of insects |
Order Odonata - dragonflies Order Orthoptera - grasshoppers, crickets; large hind legs for jumping Order Coleoptera - beetles; largest insect order; 150,000 species - dung beetle: feed on feces and lay their eggs in it too Order Lepidoptera - butterflies, moths Order Hymenoptera - ants, bees, wasps; social insects |
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Echinoderms |
Represent the transition from invertebrate body to vertebrates. - related to chordates by molecular evidence and deuterostome characteristics - starfish, sea urchins, sand dollars, feather stars and sea cucumbers * marine bottom dwelling invertebrates - adults are radially symmetrical with 5 arms extending from central disc - internal endoskeleton under epidermis composed of calcium plates * bumps, spines and pinchers on surface for protection (prevent other organisms from attaching to exposed surfaces) - no specialized excretory or circulatory systems - starfish can regenerate lost arms or entire body from arm with central disc |
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Echinoderm respiratory system |
gills on surface exchange gases |
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Echinoderm vascular system |
Water vascular system - system of fluid filled tubes in body - water flows in and out of water vascular system through madreporite disc on dorsal surface * water moves into ring canal then through radial canals into arms - branches from radial canals end in tube feet on underside of arms * water pressure attaches, releases tube feet to adhere to surfaces, move, grasp prey |
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Echinoderm digestive system |
Complete - short tube from mouth on ventral surface to anus on dorsal surface - digestive glands in each arm process food - nerve ring in central disc: nerves extend into arms - eyespots at tips of arm detect light, movement |
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Echinoderm reproduction |
Separate sexes release gametes into water to form zygote - zygote forms bilateral larva * indicates echinoderms probably evolved from bilateral ancestor Can also regrow and repair body parts if they are removed |
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Feather stars |
Echinoderm Brittle stars; most primitive Echinoderms - living forms similar to fossil forms |
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Sea urchins and sand dollars |
Echinoderms Spines protrude through internal skeleton - 5 rows of tube feet but no arms * tube feet function for gas exchange not movement |
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Sea Cucumber |
Echinoderm Elongated leather bodies Bilaterally symmetrical - 5 rows of tube feet: some tube feet modified into feeding tentacles * reduced endoskeleton and no spines (more soft and flexible) - sea cucumbers produce defensive compounds |
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Chordates |
Contains all organisms with backbones: 52,000 species All chordates share several embryo characteristics during some stage of development: - all are deuterostomes - bilateral symmetry - notochord - dorsal, hollow nerve cord parallel to notochord just under dorsal surface * develops into brain and spinal chord in most groups - gill (pharyngeal) slits - muscular tail with segmented muscles for movement and balance |
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Notochord |
Flexible rod that supports embryo body in Chordates - develops into spinal column with vertebrae that enclose spinal chord |
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Gill (pharyngeal) slits |
Grooves that open to outside in Echinoderms - pharyngeal slits present in all chordates at some time during the life cycle - allow water to move through mouth without entering digestive tract - adaptation for filter feeding in invertebrate chordates - gills for gas exchange in sharks, fish - develop into ear, head, neck structures in tetrapods (do not form gills) |
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3 subgroups of Chordates |
Lancelets - invertebrates Tunicates - invertebrates Vertebrates - backbone; Subphylum Vertebrata - 7 groups |
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Lancelets |
Basal invertebrate chordates - bilaterally symmetrical with pairs of muscles and tail - adults retain dorsal hollow nerve cord and notochord throughout life - filter feeders: bury body in sand with mouth and cirri exposed - gas exchange across body surface not pharyngeal slits |
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Cirri |
Tentacle like structures that prevent large particles from entering the mouths of Lancelets - water enters mouth and exits through pharyngeal slits - food particles trapped in mucus move into digestive tract |
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Tunicates |
Sea squirts; marine, sessile animals; invertebrate chordates - resemble chordates during larva stage only * bilaterally symmetrical, tail, notochord, dorsal, hollow nerve chord and pharyngeal slits - larva body twists during development to form adult * only pharyngeal slits retained in adult - adult sea squirts draw water into mouth through incurrent siphon * pharyngeal slits filter food from water into the digestive tract * water collects in antrum (cavity) and is expelled through excurrent siphon * gas exchange occurs across body wall not pharyngeal slits |
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Vertebrate chordates |
Subphylum Vertebrata; craniates; chordates with a head - head contains brain, eyes, other sensory organs and mouth * coordinate more complex movements, feeding and avoidance behaviors - all except hagfish have endoskeleton with backbone composed of vertebrae * vertebrae composed of cartilage or bone - encloses spinal chord - vertebrates have 2 clusters of HOX regulatory genes * influence 3D shape of body - leg/ segment positions along body axis - pharyngeal slits form gills or other structures - complete digestive system with separate mouth and anus - urinary system: kidneys remove fluid wastes from blood |
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Circulatory system in vertebrate chordates |
Heart with 2, 3, or 4 chambers - 2 closed circulatory pathways to lungs, body * blood enclosed completely in blood vessels (maintains constant blood pressure) * hemoglobin in red blood cells transport O2 |
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7 Vertebrate chordate groups |
Hagfish Lampreys Sharks (cartilage fish) Bony fish Amphibians Reptiles and birds Mammals |
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Hagfish |
Jawless; oldest craniates in fossil record; 500mya - most basal vertebrate group * head with cartilage skull and notochord - no vertebrate or endoskeleton * slime glands secrete gelatinous, mucousy, defensive slime when threatened (slime absorbs water - coats mouth and gills of predators and scavengers) |
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Lampreys |
Basal lineage of vertebrates with backbones - jawless: parasitic; rasping mouth penetrates skin to ingest blood - cartilage skeleton: partial skull and nerve chord - larvae stage resembles lancelets: filter feeders in fresh water |
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Jawed Vertebrates |
Gnathostomes Hinged jaws with teeth hold, kill, shred, crush prey and protect themselves - hinged jaws are thought to have evolved from gill support bars in pharyngeal slits * jaws are characterized as 1 of the most important adaptations in vertebrate evolution. Enlarged brain with more highly developed functional regions. Mineralized endoskeleton - cartilage or bone Movable, paired appendages |
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Placoderms - jawed, armored fish from Devonian; 395 mya- may represent ancestor for fish |
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Sharks, stingrays |
Cartilaginous fish - thick skin with tooth like scales - cartilage endoskeleton: unique derived characteristic - most must swim to move water across gills for gas exchange and remain buoyant - most are carnivorous predators: jaws contain multiple rows of teeth * teeth constantly formed - rear teeth move forward as front teeth are lost - closed circulatory system when 2 chambered heart and single circulation pathway to lungs and body - respiratory: water enters through mouth and spiracles, passes over gills and exits though gill slits * spiracles - vestigial 1st gill slits posterior to eyes (allow water intake during feeding - O2 to brain and eyes) - large stomach and liver, short intestine * spiral valve slows food movement through intestine - increases surface area for absorption * liver aids in buoyancy - no swim bladder - reproductive, excretory, digestive tracts merge into single tube opening to outside: cloaca * release urine, feces, eggs - whale sharks and manta rays are filter feeders |
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Shark and stingray sensory adaptations |
- lateral lines: receptors along each side of body sense vibrations in water and water velocity - sharp vision: some color vision - keen sense of smell: primary sense - receptors on head detect electrical fields generated by muscle contractions of prey or predators * help baby sharks avoid predators - entire body senses sound * transmits sound sensations to inner ear; no eardrums |
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Shark and stingray reproduction |
Mostly internal fertilization of eggs - males have claspers on pelvic fins * transfer sperm into female |
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Bony fish |
Most successful group of vertebrates; 25,000 species; fresh water and marine species - dominant since Devonian: "age of fishes" * earliest forms probably had gills and lungs - skin covered by flattened, mucus covered body scales: reduces drag when swimming * increase in size as fish grows - lateral lines: detect vibrations, water velocity - 4 or 5 pairs of gills function for gas exchange - swim bladder allows fish to maintain buoyancy, rise or descend in water - reproduction: mostly external fertilization after eggs released in water - complete digestive system - kidneys remove fluid wastes - closed circulatory system with 2 chambered heart and single circulation pathway to lungs and body |
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Operculum |
Bony flap covering the gills in bony fish - operculum movement draws water into mouth and out over gills * O2 diffuses into blood, CO2 diffuses into water |
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2 main groups of bony fish |
Ray finned - most dominant, familiar group; bass, perch, tuna (21,000 species) - bony rays support and manipulate fins, defend against predators * sturgeon, gar, paddlefish - most primitive ray finned fish - seahorse: Hippocampus = no scales Lobe finned - 2 groups Coelocanthe and other |
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Coelocanthe lobe finned bony fish |
First identified from fossils; "living fossils" - living specimens found off Madagascar (1939), indonesia (1999) * Coelocanthes possibly resemble ancestors of first land vertebrates - 4 fleshy, paired fins with supporting bones could function as legs |
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Other lobe finned bony fish |
Have both lungs and gills - some "living fossils" - normally use gills for respiration - use lungs to gulp air at surface when water becomes stagnant * lungfish burrow into mud when water dries up completely (enter state of reduced metabolism - estivation) - living lobe finned, lung fish found in South America, Africa, Australia |
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Tetrapod group |
Vertebrates with head, neck, jaws, 4 legs and 4 feet - probably evolved from lobe finned fish with gills: Coelocanthe; 365 mya - 4 legs replaced fins: more efficiently and effectively supported weight on land * digits on feet transmit muscle generated forces to ground when walking * pelvic bones fused to vertebrae (transfers forces from hind legs on ground to rest of body) |
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Tiktaalik |
Fossil characterized by both fish and tetrapod characteristics; 375 mya - scales, fins and gills: fish like - neck, shoulders, ribs, forelimb anatomy and lungs: tetrapod like * probably did not walk on land |
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Amphibians |
First amphibians probably evolved from air breathing lung fish - became dominant terrestrial group in Carboniferous ("age of amphibians") - most amphibians went extinct Permian and were replaced by reptiles |
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Characteristics of Amphibians |
Gas exchange by lungs and/ or across skin (no gills) Closed circulatory system with 3 chambered heart - some mixing of oxygenated and deoxygenated blood * double blood circulation pathway - 1 to lungs, other to body Eardrums detect airborne sound. Eyelids protect and prevent drying of eye |
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2 life cycle stages in amphibians |
Larvae and adult Larvae - tadpole; fish like; herbivorous - tadpole undergoes metamorphosis to form adult Adults - frogs live in aquatic or terrestrial habitats; carnivorous |
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Amphibian reproduction |
External fertilization; sperm applied to eggs as they are laid - eggs laid in moist environment to prevent drying out (no protective shell) |
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Living amphibians |
Salamanders Frogs Toads |
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Salamanders |
Amphibians with tails; resemble tetrapod ancestors - 4 legs extend from body at right angle * move side to side when walking (primitive characteristic) - many adult salamanders look like larva (paedomorphosis) * retain gills - Axolotl |
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Frogs and Toads |
no tails; 5000 species - powerful hind legs for hopping, swimming - long sticky tongue captures prey - communicate through vocalizations: croaking * attract females, migrate to breeding sites, defense - skin often brightly colored, camouflaged, distasteful and/ or poisonous |
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Reptiles |
Evolved from amphibians and became dominant in Mesozoic ("age of reptiles") - all modern reptiles except crocodilians descended from group called Cotylosaurs Reptiles replaced amphibians because amphibians were dependent on water for survival. - thin moist skin, external fertilization, fish like eggs without shell, aquatic larvae - All reptiles except 4 modern reptile groups and birds go extinct at end of Cretaceous (65 mya) |
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Reptiles are fully terrestrial |
4 large legs more directly positioned under body to support weight. - elevates body off ground and enhances movement on land (clawed digits) Skin covered by keratinized, waterproofing scales - prevents dehydration in air Reptiles have larger lungs than amphibians - muscles expand and decrease rib cage volume to control breathing Kidneys help conserve water Heart is mostly 4 chambered although ventricles are not completely separated in some Amniotic egg - "land egg"; one of the most important adaptations to terrestrial life |
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Amphibians are cold blooded |
Ectothermic; adjust body temp to environment - regulate body temp through behavioral adaptations, not metabolism * bask in sun to absorb heat or seek shade to reduce heat absorption - birds endothermic: maintain body temp through metabolism (similar to mammals) |
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Amphibian amniotic egg |
Characterized by protective shell, nutrients and internal water supply - membranes separate embryo from waste, nutrients, albumen, shell - amniotic membrane: forms amniotic cavity with amniotic fluid around embryo - allantois sac membrane: collects, removes urinary wastes; gets larger with age - yolk sac membrane: contains stored food for embryo; gets smaller with age - chorionic membrane: outermost membrane; surrounds everything * exchanges gases through blood vessels at shell - albumin: egg white; stores nutrients and water between chorion and shell - shell: some leathery or hardened by calcium carbonate; minimizes or prevents dehydration * amniotic egg fertilized internally before shell secreted (no larva stage) |
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Ancestral amniotes diverged into 2 linneages |
Reptiles and synapsids (therapsids) - synapsids: single opening on skull behind eye socket * evolve into mammals in Jurassic; 150 mya |
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Reptiles divided into 2 groups based on skull structure and number of openings behind eye |
Anapsids Diapsids |
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Anapsids |
- no openings in skull; oldest group - turtles and tortoises: relationships to other reptiles unclear * box like shell - carapace (dorsal) and plastron (ventral): allows head, legs to be withdrawn into shell when threatened * keratinized beak without teeth |
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Diapsids |
2 openings on skull behind eye socket; passageway for jaw muscles - Archosaurs - lepidosaurs - ichthyosaurs and plesiosaurs |
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Archosaurs |
- Crocodiles and alligators - pterosaurs - 2 groups of dinosaurs |
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Crocodiles and Alligators |
Reptile - Diapsid - Archosaurs - evolve in Triassic - 23 living species - upturned nostrils for breathing, laterally flattened tail, cone shaped teeth - completely separated 4 chambered heart - closest living relatives of birds - display parental behavior like birds * make and guard nests, feed and care for young |
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Pterosaurs |
Reptiles - Diapsid - Archosaurs Flying dinosaurs; 1st tetrapods with flapping wings for flight - thin skin stretched from body to elongated forelimb digit formed wing * Quetzalcoatlus - wing span of 12 meters (found in big bend) |
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2 groups of dinosaurs |
Reptile - Diapsid - Archosaur Some may have been warm blooded - Ornithischians - saurischians |
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Ornithischians |
Reptile - diapsid - archosaur - dinosaur Bird hipped dinosaurs; herbivores with large bodies - Stegasauraus, Anklyosaurus: armor plates, crests, tail clubs - Triceratops: horned |
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Saurischians |
Reptile - diapsid - archosaur - dinosaur Lizard hipped dinosaurs - giant quadriped herbivores: Apatosaurus - bipedal carnivores: tyranosaurus rex, velociraptor - birds |
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Lepidosaurs |
Reptile - diapsid - tuataras - snakes and lizzards |
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Tautaras |
Reptile - diapsid - lepidosaurs Sphenodon; surviving populations found only on islands off New Zealand - rats brought by explorers eliminated all other tuatara populations |
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Snakes and lizards |
Reptile - diapsid - lepidosaur Squamates (shed skin) - lizards most numerous and diverse reptile group except birds * most are predators - iguana is herbivorous - snakes: no legs; evolved from ancestors with legs * unique derived trait - boas have vestigial legs |
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Snakes are carnivorous |
hunt and eat prey; all have teeth - no eardrums: body detects ground vibrations - tongue moves odor molecules to olfactory receptors in mouth * nostrils dont smell, just for respiration - heat sensitive organs between eyes and nostrils: pit vipers * detect warm blooded prey - some inject toxins through specialized fangs - disarticulating jaws open to swallow large prey |
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Ichthyosaurs and Plesiosaurs |
Reptile - Diapsid Extinct aquatic dinosaurs - ichthyosaurs: propoise like - plesiosaurs: long neck, paddle limbs ; Loch Ness |
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Birds |
evolved from bipedal, lizard hipped, saurichian dinosaurs - Archaeopteryx: oldest fossil birds from the Jurassic * had teeth, jointed tail, feathers and clawed digits on wings * function of feathers unclear - insulation, courtship, camouflage, possibly flight - modern birds have beak, remnants of jointed tail and feathers: diapsid skull * 10,000 described species of birds in 28 orders |
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Benefits of flying |
- enhance hunting and scavenging - escape predators - migrate to other locations for food, breeding or seasonal change |
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Feathers |
Derived from keratinized skin scales - feathers attached to modified forelimbs - feathers composed of air filled shaft and rachis with vanes (composed of barbs with barbules and hooks) * hooks on barbules connect to hooks on other barbules - preening keeps feathers functional: worn |
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feather types |
feathers replaced each year * flight feathers - lift * contour feathers - streamline body shape * downy feathers - fluffy feathers without hooks; trap air for insulation - wings powered by large pectoral muscles attached to keel on breastbone |
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Other adaptations for flight |
Endothermic - warm blooded; high metabolic rate maintains high body temp - downy feathers and fat layer retain body heat Efficient respiratory system for gas exchange - thin walled air sacs attached to lungs - air sacs fill most of body cavity and extend into bones * reduces body weight, improves air flow and o2 uptake, dissipates heat 4 chambered heart - rapid heart rate maintains constant blood flow to muscles Light weight body - hollow bones, light skull, no teeth |
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Bird brains |
larger than amphibians and other reptiles - highly developed color, hearing, equilibrium, smell senses - best eyesight of all vertebrates |
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Bird beaks/ bills |
Composed of keratin; adapted for different diets - finch, parrot: large, strong beak (seeds and nuts) - hawks, vultures: sharp beaks (carnivores) - hummingbirds: long, slender beaks (nectar) - ducks, spoonbills, flamingos: water feeders *extract particulates from water - insect eaters: slender beak |
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Birds stand on 2 legs |
feet adapted for different functions - predators: eagle (long talons) - perching: cardinal, sparrow, jay (>50% of all birds) - grasping: woodpecker - swimming: ducks (webbed feet) |
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Flightless birds |
Ratites: ostrich (330 lbs), emu, rhea; no keel, small pectoral muscles - biogeographical distribution patterns of ratites illustrate continental drift Penguins: feathers shed water, insulate body - swimming powered by large pectoral muscles: resembles flight movement - wings function like flippers: convergent adaptation to marine environment |
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Mammals |
Evolved in early Permian from synapsid reptiles (250 mya) - synapsids: characterized by a single opening in skull behind eye socket (Dimetrodon) - 1st true mammals evolve in jurassic (200 mya) * small, nocturnal, insect eating, shrew like organisms * all 3 mammal lineages present in early Cretaceous (monotremes, marsupials, placentals - 65 mya) |
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Mammal characteristics |
5,300 described living species - body hair functions for protection, cushioning, insulation, filtering air - endothermic: body temp. generated and maintained by high metabolism * fat layer under skin and sweat glands help regulate body temp. - limbs oriented to support body more vertically and higher off ground 4 chambered heart - similar to birds * maintains constant blood pressure and blood flow to active tissues - respiration: diaphragm muscle increases breathing efficiency * require more o2 for metabolism - 1 bone in lower jaw Enhanced olfactory and visual senses |
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4 specialized tooth shapes in mammals |
Incisors - shearing, cutting Canines - puncturing Premolars, molars - crushing and grinding - teeth in upper and lower jaws occlude * fit together to more efficiently chew, grind foods |
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Mammal brains |
Larger than other mammals - more complex cerebral cortex - capable of analyzing stimuli, information and learning * mammals have well developed behaviors (some instinctive, others acquired through experiences) |
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Fertilization in mammals |
Internal fertilization and embryo development occurs in uterus of mother in all except monotremes - placenta in uterus delivers o2 and nutrients to young, removes wastes - young born alive and sustained by milk from mammary glands of mother - extended parental care for young |
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3 major mammal lineages |
Monotremes Marsupials Placentals |
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Monotremes |
Represent early branch in mammal evolution - exhibit combination of reptile and mammal characteristics - monotremes not considered to be ancestral to other mammals - 2 surviving groups of monotremes in Australia and New Guinea * spiny anteaters (eggs in pouch) and duck billed platypus |
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Monotreme reptile like characteristics |
- lay eggs with leathery shell - cloaca opening for digestive, urinary and reproductive tracts - duck like bill with no teeth * sensory receptors on bill detect movement, electrical fields of prey - webbed front feet: venom spurs on claws on rear feet |
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Monotreme mammal like characteristics |
- hair - secrete milk * no nipples or placenta |
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Derived shared characteristics of marsupials and placentals |
- endothermic: higher metabolic rate than monotremes - embryo develops in uterus * placenta transfers nutrients, gases and wastes between mom and embryo - young born alive - nipples direct milk from mammary glands to young |
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Marsupials |
240 living species in Australia and nearby islands - kangaroos, koalas and opossum (only marsupial in North America) - initial embryo development occurs in uterus * partially developed embryo born alive about a month after fertilization - embryo moves to marsupium (abdominal pouch) * completes development attached to nipple |
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Placental Mammals |
All other mammals (100 mya) - embryo develops completely in uterus connected to mom by placenta * most offspring helpless at birth * some quickly mobile - horses, zebras, wildebeest (rapidly stand to move with mom) - placentals eliminate marsupials on all continents except in Australia * Australia - island continent; placentals did not reach Australia |
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7 orders of mammals |
Insectivora Chiroptera Primata Rodentia Carnivora Probisoidea Cetacea Primata |
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Order Insectivora |
Shrews Moles - probate mammal ancestral group |
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Order Chiroptera |
Bats (22% of placenta species) |
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Order Primata |
Lemurs Monkeys Apes Humans - 250 living species (4% of placental species) - primates thought to have evolved in Cenozoic |
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Rodentia |
Rats Squirrels 455 placental species |
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Order Carnivora |
Lions Tigers Bears ...oh my |
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Order Probisoidea |
Elephants Tapirs - elongated upper incisors: tusks - prehensile trunk |
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Order Cetacea |
Whales Porpoises Dolphins - adapted for aquatic environment * nostrils on top of head * streamlined bodies, paddle like forelimbs, no hind limbs, insulating blubber - largest brain of all animals - echolocation: loudest sound produced by animals |
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Primate characteristics |
- hands and feet modified for arboreal life: grasping branches, objects - well developed shoulder, elbow and wrist joints - more enhanced visual sense: most have 3 color vision - larger brain with increased cerebral cortex surface area - shorter jaw with specialized teeth for varied diets - usually 1 baby born from each pregnancy |
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Primate hands and feet |
- 5 functional digits on each hand and foot with opposable thumb and toe - flat nails on digits instead of claws - skin ridges on fingertips and toes * detect sensations and pickup objects |
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Shoulder, elbow and wrist joints in primates |
- well developed - full range of motion at shoulder - rotate forearm at elbow |
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Vision of primates |
- more enhanced - most have 3 color vision - binocular vision: overlapping visual fields increase depth perception * increases hand/ eye coordination |
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Brain of primates |
Larger brain with increased cerebral cortex - more capacity for analysis and integration - increased capacity to learn - increased memory |
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Usually 1 baby born from each pregnancy in primates |
- 2 mammary glands produce milk * more attention and extended care for young - usually live in extended social groups * young interact with and learn from elders/ others |
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Order Primata divided into 3 subgroups |
Prosimians Tarsiers Anthropoids |
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Prosimians |
Arboreal with more laterally positioned eyes - lemurs on Madagascar (225 species) - lorises in Africa, India and Southeast Asia |
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Tarsiers |
Arboreal and nocturnal with binocular vision; Philippines and East India - ancestral primates: DNA indicates tarsiers more related to anthropoids than lemurs |
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Anthropoids |
Monkeys Apes Humans 2 lineages of monkeys - New world monkeys - old world monkeys Hominoidea |
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New world monkeys |
All arboreal; howler, spider, capuchin - flat nose and long, prehensile tail for grasping |
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Old world monkeys |
arboreal and ground dwelling groups - longer nose and no prehensile tail - baboons, mandrills, rheus, macaques |
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Hominoidea |
Non human apes; no tails Probably not derived from old world monkeys 4 groups: (all have large bodies, long arms, short legs walk semi erect, large skull and brain) - gibbons: smallest (lesser) ape: arboreal; SE Asia - Orangutan: Asian great ape; 1 arboreal species in Borneo and Sumatra - Gorillas: 2 species in Africa; larges primate; vegetarian * Dian Fossey - studied gorilla behavior - Chimpanzees |
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Chimpanzees |
Hominoidea Most intelligent ape; most closely related to humans - can assume bipedal gait - use tools for feeding and protection - communicate vocally with each other and with humans - form groups that cooperate for hunting and foraging * varied diet includes meat - Jane Goodall: studied chimp behavior for many years * Frodo, Samwise, Gremlin * documented aggression, murder, carnivory |
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Humans |
Family Hominidae; Homo sapiens - share similar primitive characteristics with all mammals - share derived characteristics with primates - unique derived human characteristics: do not occur in primates - humans and chimps evolved from common ancestor |
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Similar primitive characteristics between mammals and humans |
- hair - endothermy - 4 chambered hearts - mammary glands and milk - rearing of live young - mammalian teeth |
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Shared derived characteristics between primates and humans |
- opposable thumbs - nails instead of claws - binocular vision |
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Unique derived human characteristics |
Do not occur in primates Fully bipedal gait - upright posture and walk on 2 legs * arched foot - maintains balance Straighter spine - connects to base of skull - elevates skull and eyes higher above ground * more easily look for allies, predators and food Hands and forelimbs not used for walking - specialized for other uses: manipulate objects, carry objects while walking * thumb manipulation more precise in humans than other primates - carry out more efficient hand movements than other primates Large brain - capable of language, symbolic thought, manufacture and use of tools |
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Humans and chimps evolved from a common ancestor |
About 5 mya based on molecular evidence Thought to have 99% of genes in common - more related to each other than either are to gorillas, orangutans or gibbons - hemoglobin, cytochrome C sequences exactly the same in humans and chips * 2 amino acid differences between humans and chimpanzees Differences exists in 19 regulatory genes that control other genes - Account for some of the differences between humans and chimps |
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Fossil record of humans |
Fragmentary fossils from about 20 extinct species - show more similarities to humans than to chimpanzees * hominoids - humans, bipedal ancestors |
