Domain Bacteria Domain Archaea Domain Eukarya Common ancestor Kingdom: Animals Domain Eukarya VERTEBRATES!!!

postanal tail notochord hollow dorsal nerve cord pharyngeal pouches becomes brain & spinal cord becomes vertebrae becomes gills or Eustachian tube becomes tail or tailbone CHARACTERISTICS: NOTOCHORD PHARYNGEAL POUCHES POST ANAL TAIL DORSAL NERVE CORD

VERTEBRATE CHARACTERISTICS: ALL CHORDATE CHARACTERISTICS PLUS: Bones or cartilage around a dorsal nerve cord Cranium (skull) to protect brain Endoskeleton made of bone or cartilage Closed circulatory system fish, amphibians, reptiles, birds, mammals

Notochord: flexible rod Helps organize developing cells in embryo Replaced by spinal cord in most vertebrates Becomes the vertebrae

Become gills in some vertebrates Become back of throat and inner ears in humans

Pharyngeal arches appear during 4 th week Tail disappears at approximately 8 weeks

 Characteristics  body structure  bony OR cartilaginous skeleton  Scales, fins  Lungs/swim bladder  body function  gills for gas exchange  two-chambered heart; single loop blood circulation  ectotherms  reproduction  external fertilization  external development in aquatic egg salmon, trout, sharks 450 mya gills body

Evolution of tetrapods Tibia Femur Fibula Humerus Shoulder Radius Ulna Tibia Femur Pelvis Fibula Lobe-finned fish Humerus Shoulder Radius Ulna Pelvis Early amphibian Evidence suggests lobe finned fish are ancestors of amphibians

Intermediate between fish and early tetrapods  Fins have basic wrist bones and simple fingers  Earliest fish with a neck  Discovered by Neil Shubin and Ted Daeschler in

lung buccal cavity glottis closed  Characteristics  body structure  legs (tetrapods)  Thin, moist skin  body function  lungs (positive pressure) & diffusion through skin for gas exchange  three-chambered heart/2 loops  Ectotherms  Excrete UREA  reproduction  external fertilization  external development in aquatic egg  metamorphosis (tadpole to adult) frogs salamanders toads 350 mya

 Characteristics  Dry, scaly skin  body function  lungs for gas exchange  three-chambered heart/2 loops (except crocodilians)  ectotherms  excrete URIC ACID  reproduction  INTERNAL fertilization  external development- AMNIOTIC egg 250 mya dinosaurs, turtles lizards, snakes alligators, crocodile embryo leathery shell chorion allantois yolk sac amnion

amnion -bag of waters; the extraembryonic membrane of birds, reptiles, and mammals, which lines the chorion and contains the fetus and the amniotic fluid IMPORTANT DEVELOPMENT AMNIOTIC EGG- reptiles didn’t have to return to water to lay eggs

 Characteristics  body structure  feathers & wings  thin, hollow bone; flight skeleton  body function  very efficient lungs & air sacs  four-chambered heart/2 loops  endotherms  excrete URIC ACID  reproduction  INTERNAL fertilization  external development in AMNIOTIC egg 150 mya finches, hawk ostrich, turkey trachea anterior air sacs lung posterior air sacs

 Characteristics  body structure  hair  specialized teeth  body function  lungs, diaphragm; negative pressure  four-chambered heart/2 loops  endotherms  reproduction  internal fertilization  internal development in uterus  nourishment through placenta  birth live young  mammary glands make milk 220 mya / 65 mya mice, ferret elephants, bats whales, humans muscles contract diaphragm contracts

 Sub-groups  monotremes  egg-laying mammals  duckbilled platypus, echidna  marsupials  pouched mammals  short-lived placenta  koala, kangaroo, opossum  placental  true placenta  shrews, bats, whales, humans

 Which vertebrates lay eggs with shells?  Which vertebrates are covered with scales?  What adaptations do birds have for flying?  What kind of symmetry do all vertebrates have?  Which vertebrates are ectothermic and which are endothermic?  Why must amphibians live near water?  What reproductive adaptations made mammals very successful?  What characteristics distinguish the 3 sub-groups of mammals?