BIO120H1 Lecture Notes - Lecture 16: Kangaroo Rat, Sonoran Desert, Ecophysiology
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BIO120H1 Full Course Notes
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Lecture 16: trade-offs and compromises: conclude and summarize physiological ecology of animals, begin on plants. Two reasons why natural selection produces deeply imperfect organisms. Being good at x may necessarily imply being bad at y. E. g. weasel: long and skinny; not a good shape for cold environment. Constraints but they live in cold environment; Natural selection builds on what is already there, especially existing developmental programs. Don"t invent new structure; natural selection limited. A fish in a lake ned to have a proper concentration of body tissue; a fish in saltwater needs to adjust accordingly. Example: dealing with extreme water stress: kangaroo rat (dipodomys ), sonoran desert. K-rat tactics for conserving water in hot, dry environments. They don"t need to drink water in their whole lives! Water come from seed diet(dry but fatty); they can metabolize the fat into. Erect posture, bipedal (stand on two legs )less heat gain from ground.
