1. Theory of Evolution Ch. 15

2. (15-1) Evolution Change of organisms over generations w/ a strong natural modification process “Change over time”

3. Scientific Theories Explain data Generations of predictions Falsifiable

5. Lamarck’s Theory Use & Disuse: parts of body that are used extensively become larger & stronger while those that are not used deteriorate –Acquired traits

6. Lamarck (cont.) Ex: –Webbed foot = stretching of membrane b/w toes (water birds) 1st to say: –Organisms change over time –New organisms are modified descendants of older types

8. Darwin & Wallace’s Theory Natural Selection: organisms best suited to their environment reproduce more successfully than others “Survival of the fittest”

9. Charles Darwin’s Voyage on the Beagle

10. Darwin’s Studying Ground

11. Darwin’s Observations 13 similar but separate species of finches –Specialized for food Similarities lead to belief of a common ancestor

12. Darwin’s Conclusions 1.Descent w/ modification 2.Modification by natural selection

13. Descent w/ Modification Newer species are modified descendants of older species All species descended from 1 of a few original types of life

14. Modification by Natural Selection How evolution occurs Environment limits pop.’s growth Not all individuals in a pop. are identical & environment affects them differently

15. Natural Selection (cont.) Individuals w/ favorable traits reproduce more often than those w/ unfavorable traits Thus favorable traits will be passed down more often

16. Adaptation Inherited trait that inc. an organism’s chance of survival in a particular environment –Based on genes

17. Fitness Ability to survive to propagate their genes (have babies)

18. Lamarck vs. Darwin

21. (15-2) Evidence of Evolution 1.Biogeography Geographical distribution of species 2.Fossil Record Type & order of fossils

22. Evidence (cont.) 3. Homologous structures Similar b/c of common ancestry 4. Comparative embryology Study of structures that appear during embryonic development 5. Molecular biology DNA & proteins

23. Biogeography New organisms arise in same geographic area where similar forms already lived Ex: kangaroos only in Australia

24. Fossil Record Fossils: impressions of organisms from the past mineralized in rock Links b/w modern forms & ancestors

25. Distribution of Fossils Law of superposition: lowest layers of rock are oldest Fossil-bearing strata show when organisms became extinct Mass extinction: brief period in which large #’s of species disappeared

27. Homologous Structures May have different functions but have similar anatomy Shows a common ancestor Ex: bird beaks & forelimbs

29. Common Ancestor

32. Analogous Structures Similar look & function, but different embryological development & anatomy Ex: bird & insect wings

33. Vestigial Structure Part of an organism w/ little or no function, but had a function in an ancestral species Ex: human tailbone & appendix

38. Comparative Embryology All vertebrate embryos go through a stage in which they have gill pouches & tails

40. Molecular Biology The more similar the sequence, the more closely related 2 species are to each other DNA, RNA, proteins (amino acids)

41. Amino Acid Chart

42. (15-3) Patterns of Evolution 1.Coevolution 2.Convergent Evolution 3.Divergent Evolution Pattern & speed result from changes in the environment

43. Coevolution Change of 2 or more species in close association w/ each other Ex: –Predator-prey –Parasite-host –Plant-animal pollinator

44. Convergent Evolution Organisms appear to be similar but are not closely related Environment selects similar phenotypes Ex: shark & porpoise

46. Divergent Evolution 2 or more related populations become more dissimilar in response to different habitats Adaptive radiation –Galapagos finches Artificial selection –Domestic dogs

47. Divergent evolution of Grand Canyon squirrels

48. Peppered Moth Evolution