2. The process of evolution drives the diversity and unity of life

3. 2006-2007 -- Theodosius Dobzhansky March 1973 Geneticist, Columbia University (1900-1975) “Nothing in biology makes sense except in the light of evolution."

4. Darwin: Historical Man of Mystery

6. Plato & Aristotle (427 – 342 B.C.) Ideal organisms already adapted perfectly to environment, so no evolution Natural Theology (1700s) Creator specifically designed all organisms Carolus Linnaeus created taxonomic system to discover God’s order

7. Georges Cuvier (1769-1832) Succession of fossils in sedimentary rock – throughout layers, species appear & disappear Believed in catastrophism – due to massive changes of environment

8. James Hutton (1726-1797) – gradualism – little changes add up Jean Baptiste Lamarck (1700s) Use & disuse (use creates strength, disuse creates weakness) Inheritance of acquired characteristics (pass those strengths to offspring – ex:giraffe neck)

9. Lamarck’s major contributions – Evolution explains fossil record & current diversity Organisms adapt to environment

10. The man, the legend, the icon!!

11. 1809-1882 22 years old – HMS Beagle – on board as “conversation companion” to captain Voyage to chart coastline of S.A. Darwin interested in geographic distribution of species, similarities, & differences on Galapagos islands

13. Warbler finch Woodpecker finch Small insectivorous tree finch Cactus finch Sharp-beaked finch Small ground finch Medium ground finch Large ground finch Insect eaters Bud eater Seed eaters Cactus eater Warbler finch Tree finches Ground finches

15. Seed eaters Flower eaters Insect eaters

16. Finches were studied – very different from island to island Beaks have “adapted” to environment (food source/location) Natural selection – driving force of evolution (“Descent with Modification”) Biological diversity – product of evolution

17. (a) Cactus eater. The long, sharp beak of the cactus ground finch (Geospiza scandens) helps it tear and eat cactus flowers and pulp. (c) Seed eater. The large ground finch (Geospiza magnirostris) has a large beak adapted for cracking seeds that fall from plants to the ground. (b) Insect eater. The green warbler finch (Certhidea olivacea) uses its narrow, pointed beak to grasp insects.

18. Unity of life explained by common ancestor

19. As life progressed, accumulation of diverse modifications  diversity of today Link to Linnaeus – more taxonomic levels in common, more recent shared ancestor

20. Differential success in reproduction Interaction between environment & inherited variety of individuals within a population Product is adaptation of populations of organisms to their environment

21. Differential Success in Reproduction

22. Environmental interaction Ex: Peppered Moth Industrial melanism Prior to Industrial RevolutionAfter the Industrial Revolution

23. Antibiotic/chemical resistance Drug Resistant HIV Note: in another environment, these characteristics might be considered detrimental, but in this environment, they are a benefit for these organisms.

26. Homology - similarity of characteristics from common ancestor

27. Homologous anatomical structures - Same structure, different function

28. Remember….homologous (common ancestor) NOT analogous (similar function, different structure) Spines are homologous

29. Remember….homologous (common ancestor) NOT analogous (similar function, different structure)

30. Vestigial structures can help explain link between organisms Hip bones -snake Pelvic bones – whales Human appendix

31. Biogeography (geographic distribution of species) Biogeography of the Draco lineatus complex (the Lined Flying Lizard)

32. Convergent evolution Evolutionary change due to similar environmental pressures, not a recent common ancestor placental mammals placental mammals marsupial mammals marsupial mammals

34. Convergent evolution

35. Fossil Record Millions of years ago 50 100 150 200 250 300 350 400 450 500 550 605550454035302520151050 Equus Hyracotherium Mesohippus Merychippus Nannippus Body size (kg)

36. Fossils can be dated by variety of methods Age of rocks where fossil is found Isotope decay rate (carbon-14) Phylogenetic trees Mathematical calculations from chemical properties or geographical data

37. Artificial Selection Influencing breeding based on desired traits