Vertebrates Have a backbone Include Fish Which have

Vertebrates Have a backbone

Include Fish… Which have gills and scales And live in the water. Ectotherms.

Agnatha-jawless fish Lampreys, hagfish

Chondrichthyes-cartilaginous fish -bones made of cartilage. Include skates, rays sharks.

Osteichthyes-bony fish. Includes your common Types of fish: trout, salmon, bass, goldfish, etc.

Most fish have external fertilization.

Amphibians… have gills when young and lungs when old. And need water to reproduce. Ectotherms.

If the evolutionary goal of a species is to populate every corner of the world, what reproductive disadvantages do amphibians have?

Frog eggs

Most amphibians have external fertilization.

3 chambered heart. Oxegenated blood mixes with unoxygenated blood.

What is the disadvantage of having a 3 chambered heart?

3 types of amphibians: salamanders

Frogs and toads

And Caecilians some of which have fishlike scales

Reptiles -have scales -can live in dry areas -lay soft, leathery eggs. -Ectotherms

If the goal of evolution is to populate every corner of the earth, what reproductive advantage do reptiles have over amphibians? What advantage do scales give them?

Include lizards and snakes:

Crocodilians

Turtles and tortoises

And tuataras

All reptiles have internal fertilization. Why?

Birds -have feathers -lay hard eggs -have hollow bones -endothermic -have air sacs -internal fertilization

Air sacs

--Birds are endotherms (warm-blooded). what advantage does this give them in trying to populate all the corners of the earth? --Why do birds need air sacs? --Birds sit on the nest and care for their young, unlike most reptiles and amphibians. What advantage does this give birds in populating the world.

Flightless birds can’t fly. (Duh)

Perching birds—the ones we mostly see.

Birds of prey—hawks, eagles, owls, etc

Wading birds

Water birds

Mammals -have mammary glands -have hair -give birth to live young (mostly) -endothermic -internal fertilization

Mammals give birth to live young. Why do a higher percentage of mammal offspring survive compared to any of the other classes of vertebrates?

Mammals have a four-chambered heart.

Birds and mammals have a four chambered heart. What is the advantage of having a 4 chambered heart?

Monotremes --lay eggs --have a cloaca --3 species exist: duckbilled platypus, 2 types of echidnas.

Marsupials—kangaroos, koalas, wombats, opossum --have a pouch babies develop in the pouch.

Placental mammals—all the other mammals --embryo develops in the uterus. --12 orders of placental mammals.

What reproductive advantage do placental mammals have over monotremes and marsupials? Reptiles, birds, and mammals all have internal fertilization. What advantage does this give them over other vertebrates in populating the world?

Insectivores

Sirenians

Cetaceans

Chiropterans

Rodents

Perissodactyls

Carnivores

Artiodactyls

Lagomorphs

Xenarthrans

Proboscideans

Primates

Three reproductive strategies in vertebrates: 1 -oviparous-lay eggs 2 -ovoviviparous-eggs develop inside, but offspring are born alive. 3 -viviparous-offspring get nourishment directly from mother’s body, offspring are born alive.