1. The Vertebrates

2. Chordate Evolution

3. The “Fish” Actually made up of 6 vertebrate classes Hagfish
eel-like without jaws, paired fins or bone. No vertebrae either
Lamprey
like a hagfish but with a primate vertebral column of cartilage

4. Cartilaginous fish
Shark, rays, skates and ratfish
Have jaws, bones & paired fins.
Skeleton made up of cartilage
Unique scales on skin
Lobed – fin fish
Lungfish and coelacanth
Mostly extinct
Ancestors to amphibians
Fins supported by main axis of bones

5. The “fish” you know and love
Bony fish (Ray finned fish)
Jaws, paired fins and a skeleton of bone
Fins supported by rays of bone from central axis
Lungs (in a few) or swim bladder (controls buoyancy). Gills in most
Scales covered by mucus (reduces friction)

6. More fish characteristics
Closed circulatory system w/ a series of blood vessels and a 2 chambered heart
Ventricles – muscular chambers to pump blood
Atrium – collecting chambers
In fish, oxygen-rich and oxygen-poor blood mix then go to the gills for oxygenation (again). From the gills, blood goes to the body
Ectothermic
External control of body temperature

8. Reproduction in fish Separate sexes
Sperm produced in testes, eggs in ovaries
Basically external fertilization and development
High mortality rate for eggs and young
If all the cod eggs in the world were fertilized and made it to becoming adults, in 2 years, the oceans would be solid cod!

9. Amphibians Ectothermic
Frogs, Toads, Salamanders and Mudpuppies and Newts
Aquatic larvae but terrestrial adults
Moist, thin skin w/o scales
Feet are webbed w/o claws
Use gills, lungs and skin for respiration
Eggs lack multicellular membranes or shells
Ectothermic

10. 3 chambered heart
2 atria and 1 ventricle.
Blood still mixes when it goes to the lungs and the body

11. Separate sexes
External fertilization and development
Metamorphosis in frogs
Eggs hatch and develop into a tadpole
Tadpoles are herbivorous
Legs and arms develop as tail is absorbed
Adults are carnivorous

12. Reptiles Snakes, crocodiles, alligators, turtles, lizards and caymans
Body covered with dry scales
Terrestrial
Breathe through lungs with alveoli
Ectotherm

13. 3.5 chambered heart (crocs have a 4 chambered heart)
2 atria
1.5 ventricles with a septum partially dividing the sides
Septum helps to separate the oxygen rich and oxygen poor blood
Oxygen poor blood goes to the lungs to be oxygenated and then back to the heart to be pumped to the body

14. The Amniotic Egg A big moment in evolution!!
Allowed for fetal development out of water

15. Three patterns of reproduction
Oviparity - Female lays fertilized eggs
Most reptiles, all birds & 3 species of mammals
Ovoviviparity – Fertilized eggs remain in body for a short time.
Pit vipers, some shark
Viviparity – No shell forms & young retained in body until mature. Oxygen and nutrients are transferred across a placenta
Placental mammals

16. Birds Feathers Wings Hollow boned skeleton
Endothermic – can control their internal temperature
Lungs
Oviparity

17. The 4 chambered Heart A double pump
2 atria and 2 ventricles
Septum separates 1 right and left ventricles
Oxygen rich and oxygen poor blood never mix
Right side pumps deoxygenated blood from the body to the lungs
Left side receives oxygenated blood from the lungs and pumps it to the entire body

18. Parental care
Birds are the first time we see extended parental care given to their young
Young are born helpless and need long periods of care and development before they can leave the nest.

19. Mammals Endothermic Hair 4 chambered heart Double pump Mammary glands
Extensive care given to young
Lungs
Specialized teeth (incisors, canines, premolars and molars)

20. The Human Heart

21. Three Subclasses Monotremes Duck-billed platypus, echidna
Oviparous – thin, leathery shells
Echidna incubate eggs in leathery pouch on belly
Marsupials
Kangaroo, koala, opossum, Tasmanian devil
Embryo develop for short time in uterus then emerge & go into marsupian to complete development

22. 3. Placental Mammals Viviparous – give birth to live young
Embryo gets nourishment via a placenta through the umbilical cord
After birth, young feed on milk via mammary glands
Internal fertilization, internal development