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15 Cards in this Set
- Front
- Back
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What did Shubin find in 1985 in the Bay of Fundy in Parrsboro Nova Scotia? Significance? |
Fossils in the volcanic rocks, jaws, leg bones, upper jaw, canine tooth - the Trithelodont - part reptile, part mammal. Key moment in the evolution of the human body. |
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What is significant about an 8 week old embryo's development? How does this prove reptilian ancestry? |
Humans: yolk sac develops with no yolk in it (from when our ancestors laid eggs); Reptiles laid eggs where the yolk would sustain their young until birth. |
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What evolutionary innovation in embyos led to totally new kinds of animals? |
A whole new kind of embryo, the amnion or embryonic sac, rather than laying eggs in water where they could dry out or be eaten, laid them in a sac instead. |
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What did Roger Smith discover at the Karoo? Significance? |
Predators, gorgonopsid, that looked like reptiles with mammalian features, with mammal like teeth (reptile teeth are basic). The progression of reptiles to mammals. |
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What do teeth tell us about animals? |
What they ate, what they looked like, how they lived and evolved. |
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What was significant bout the teeth of gorgonopsid? |
highly specialized teeth, incisors that came together to tear flesh, canines to pierce skin, cusps to chew food. (Better chewing, more energy from food) |
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What happened 252 M years ago? Consequences to evolution? |
Mass extinction, climate changed, wiped out most animal species including gorgonopsid. |
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Why are mass extinctions important? |
To create new opportunities for the survivors. |
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How and why did hair first evolve? |
After mass extinctions, animals had to go underground to survive, hair was a sensory organ. Then 50M years later to keep warm. |
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What is significant about Abigail Tucker's work? |
Deciphering ancient history, we share features with reptiles in our skin (nails, teeth, claws) organs. Hair, glands & teeth formed in similar ways, from folds in tissue. |
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What was significant about the master gene EDA? |
Controls how hairy you are, how many and what kind of teeth you have, building all structures that originate in the skin. (The guy with the problem: no hair, no teeth, cannot disappate body heat, no fingernails) |
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How is the hearing anatomy of mammals unique? |
Sensitive, wide range of sounds from high squeaks to low calls. Reptiles have only one earbone, we have three. |
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What did Karen Sears discover about the skulls of opossum embryos reveal about the development of ear bones in mammals? |
Opossums have 300M years of evolution in their ears. When they are born they have one ear bone, as the age to adulthood, they form the other two bones. |
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What were the two significant things about Zhe-Xi-Luo's discovery of Hadrocodium? |
Huge brain 50% bigger, relative to its body mass than any other animal before it. Advanced ear structure. |
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What event needed to take place for the mammals to emerge and truly flourish? |
Mass extinction - 65 M years ago - killed all dinosaurs so mammals could take over up on land, out of their burrows. |
