1. Evolution http://life.uiuc.edu/animalbiology/105/ ID: eee105 Password: prAIRie Lec 14 18Feb02

2. Plant-animal coevolution

4. Why aren’t all the plants eaten?

5. Plants have evolved chemical defenses

6. Why aren’t all the plants eaten? Plants have evolved chemical defenses e.g. the flavors of vegetables

7. Why aren’t all the plants eaten? Plants have evolved chemical defenses

8. Why aren’t all the plants eaten? Plants have evolved chemical defenses milkweed is toxic but a few insects have evolved resistance

9. Why aren’t all the plants eaten? Plants have evolved chemical defenses milkweed is toxic but a few insects have evolved resistance milkweed bug is toxic and has evolved warning coloration

10. Why aren’t all the plants eaten? Plants have evolved chemical defenses milkweed is toxic but a few insects have evolved resistance monarch butterfly caterpillar is toxic

11. Why aren’t all the plants eaten? Plants have evolved chemical defenses milkweed is toxic but a few insects have evolved resistance monarch butterfly istoxic too is toxic too andhas evolved bright warning colors and has evolved bright warning colors

12. Why aren’t all the plants eaten? Plants have evolved chemical defenses milkweed is toxic but a few insects have evolved resistance viceroy butterfly isnottoxic is not toxic buthas evolved bright warning colors but has evolved bright warning colors a mimic

13. Why aren’t all the plants eaten? Plants have evolved chemical defenses milkweed is toxic but a few insects have evolved resistance

14. Plant-animal coevolution plants evolved fruits

15. Plant-animal coevolution plants evolved fruits to “persuade” animals to disperse seeds

16. Are humans evolving? Yes but in surprising ways Darwin’s Descent of Man and Selection in Relation to Sex Darwin’s Descent of Man and Selection in Relation to Sex and Selection in Relation to Sex

17. Sexual selection bizarre, “useless” ornamentation secondary sexual characteristics

18. Sexual selection bizarre, useless ornamentation secondary sexual characteristics

19. Sexual selection bizarre, useless ornamentation secondary sexual characteristics

20. Sexual selection bizarre, useless ornamentation secondary sexual characteristics rainbow darter

21. Sexual selection bizarre, useless ornamentation secondary sexual characteristics in humans

22. female choice Sexual selection

23. female choice Sexual selection the naked ape ? racial differences?

24. female choice Sexual selection male combat why mammalian males are larger than females

25. female choice Sexual selection male combat Sexual selection

26. female choice Sexual selection male combat why mammalian males are larger than females in most species females are the larger sex male combat

27. in most species females are the larger sex

28. Sexual selection is a type of natural selection but there is another mechanism of evolution Genetic drift random changes in gene frequencies (1) gene flow by immigration humans are exceptional migrators

29. Gene flow by immigration e.g. Asian invasions of Europe % B bloodtype

30. Sexual selection is a type of natural selection but there is another mechanism of evolution Genetic drift random changes in gene frequencies (1) gene flow by immigration humans are exceptional migrators (2) population bottlenecks

31. Population bottlenecks In small populations random changes in gene frequencies change the population e.g. small, inbred human populations the founder effect e.g. polydacytyly

32. Population bottlenecks World population of cheetahs is small 20,000 20,000 genetically identical

33. Are humans evolving? Yes sexual selection genetic drift natural selection e.g. lactose intolerance

34. Most adult humans are lactose intolerant Only cattle-herding peoples digest milk easily

35. Are humans evolving? Yes sexual selection genetic drift natural selection But humans vigorously oppose natural selection Civilization