Phylum Chordata nerve cord many chordates are vertebrates bony vertebral column 11 10 2010 Bony fishes Cartilaginous fishes Amphibians Reptiles Birds Mammals Classify based in similarities indicating relatedness Shared through common ancestor Homology characteristics that organisms share because of a common ancestor Example 5 rays Analogy trait shared by organisms but not based on common ancestry Based on function Example wing of bat and wing of bird Establish classification base decision on shared derived features homologies Primitive 5 rays digits Macaque Derived one toed horse Aye Aye Arthropods are most successful Number of species habitats invaded number of individuals Major climate change divides periods Precambrian 3 000 million years ago First microfossils Evolution of life Paleozoic Cambrian explosion invertebrates Plants Water Then vertebrates fish o Jawless o Jaws o Armored Jellyfish trilobites worms Toxoplasmosis can only replicate in a cat Must infect rodent to infect cat Sheds infection in feces Rodents eat cat feces Rodents fear cats Toxoplasmosis affects one aspect of rodent brain place that says fear cat Changes this to love the cat Mesozoic Age of Reptiles Amniote egg invention an egg that can survive on land Water tight skin Reptiles adaptive radiations Dinosaurs Theropods dinosaurs that led to modern birds Therapsids pre mammals Heterodonts 225 MYA Pangea II one land mass Reduced coastal water mass extinctions Pre Cenozoic K T Boundary Cretaceous Tertiary Earth hit by meteor Devil s tail Yucatan Peninsula 50 of species went extinct Small mammals survived Layer of Iridium Angiosperm radiation Bats and primates Does not naturally occur on Earth Cenozoic People Eat Only My Purple Peas Ham Paleocene Eocene Oligocene Miocene Pliocene Pleistocene Holocene Age of Mammals Rodents are most successful mammals 2 bats Egg laying Mammals duck billed platypus Nurse young with modified sweat gland Incomplete thermoregulation Marsupial pouched mammals Placental internalize egg
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