1. Vertebrates Jawless fishes to Mammals Gills to Lungs Fish – one way circulation Amphibians – circulation loop Reptiles – partial septum - little mixing of blood Mammals and Birds – completely divided

2. Fish Classes Agnatha – Jawless fish, evolved about 540 MYA. Ex. Lamprey Chondrichthyes – cartilaginous fishes. Ex. Sharks and rays Osteichthyes – bony fish Gills for respiration

3. Agantha - Lamprey

4. Jaw evolution

5. Sharks Fast, powerful predators, Lateral line system – sensory organs running down the side of the body for detecting vibrations in the water

6. Chondricthyes

7. Bony Fish Hard skeleton with scales Protective operculum over the gills Swim bladder for buoyancy Ray finned fish – most bony fish like the tuna, bass, perch Lobed finned fish – ancestor to the amphibians

8. Osteicthyes

9. Perch anatomy

10. Lobed finned fish

11. Fish circulation

12. Amphibians Living a double life – part water/part land Gas exchange through diffusion Complete metamorphosis Partially divided heart Ex. Salamander, frogs

13. Amphibians

14. Amphibian circulation

15. Reptiles Watertight skin and eggs Internal fertilization – no water needed Ectothermic Scales made of keratin Lungs Dinosaurs were numerous during the Mesozoic era By about 65 MYA, the dinosaurs were gone, with only the birds left. Turtles, crocodiles, lizards and snakes

16. Reptile Heart

17. Reptiles

18. Archaeopteryx

19. Birds Class Aves Evolved during the mesozoic era Honeycombed bones for lighter weight Wings for flight, feathers made of keratin Endothermic – warmed by own metabolism No teeth, grind food with gizzard

20. Birds

21. Mammals Became diverse after the downfall of the dinosaurs Hair and mammary glands Endotermic Monotremes – duck-billed platypus and echidna, egg-laying mammals Marsupials – pouched mammals Eutherians – placental mammals

22. Mammal Heart

23. Echidna

24. Marsupials and Eutherian

25. Evolution of Primates Evolved in late Cretaceous period Arboreal – tree dwelling Limber shoulder joints allows to brachiate – swing from limb to limb Prosimians – lemurs, tarsiers Anthropoids – Monkeys, humans, apes