BIO130H1 Lecture Notes - Lecture 3: Kangaroo Rat, Cold Days, Bipedalism
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BIO130H1 Full Course Notes
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Lecture 3: physical challenges of environment for animals, emphasis on tradeoffs and alternatives: Why weasels are small predative, short furred, very long and thin in cold environment. However it lives in the north even though it can"t curl up into a sphere, only cold flat disk. They need to be thin to attack pocket gophers. Fitness gains of being a good hunter offsets fitness cost of expensive metabolism. Phenotypes of all organisms have tradeoffs (being good at x may mean being bad at y). Kangaroo rat conserves water in hot, dry environments by having erect posture, are bipedal meaning less heat gain from ground (hop like kangaroos). They hide seeds underground that can recapture water vapor lost from exhalation. Can break down fat molecules and make water. Hibernation and migration usually driven more by food supply than abiotic stress. Hummingbirds migrate to mexico in winter, eat nectar. Crossbill (bird) is a specialist on conifer seeds.
