1. C H. 17 Evidence of Evolution

2. L AWS VS. THEORIES Laws—formed by repetitive observations or conclusions Ex: law of falling objects Theory—explains why objects do what they do Ex: gravity

3. EVOLUTION & NATURAL SELECTION Evolution—biological changes in the genetic makeup of an organism over a period of time which could cause changes in the phenotype of a population; we OBSERVE things changing Natural Selection—the tendency of an organism to adapt to its environment (may lead to genetic changes) in order to survive AND reproduce

4. S ELECTIVE B REEDING & E VOLUTION Evolution is genetic change in a line of descent through successive generations Selective breeding practices yield evidence that heritable changes do occur

5. R ESULTS OF A RTIFICIAL S ELECTION Extremes in size Great Dane and Chihuahua Extremes in form Short-legged dachshunds English bulldog Short snout and compressed face Extreme traits lead to health problems

6. D OMESTICATION OF D OGS Began about 50,000 years ago 14,000 years ago - artificial selection Dogs with desired forms of traits were bred Modern breeds are the result

7. E ARLY S CIENTIFIC T HEORIES Hippocrates - All aspects of nature can be traced to their underlying causes Aristotle - Each organism is distinct from all the rest and nature is a continuum or organization

8. B IOGEOGRAPHY Size of the known world expanded enormously in the 15th century Discovery of new organisms in previously unknown places could not be explained by once accepted beliefs by Aristotle, Hippocrates, etc.

9. Fig. 17-3a, p.262 Biogeography

10. Fig. 17-3b, p.262 Biogeography

11. Fig. 17-3c, p.262 Biogeography

12. Darwin Wolf Pinta GenovesaMarchena Santiago Bartolome EQUATOR Seymour Blatra Santa Cruz Rabida Pinzon Fernandina Tortuga Isabela Santa Fe San Cristobal Espanola Floreana Fig. 17-6d, p.265 Volcanic islands far off coast of Ecuador All inhabitants are descended from species that arrived on islands from elsewhere Galapagos Islands

13. G ALAPAGOS F INCHES Darwin observed finches with a variety of lifestyles and body forms On his return, he learned that there were 13 species He attempted to correlate variations in their traits with environmental challenges

14. M ALTHUS - S TRUGGLE TO S URVIVE Thomas Malthus, a clergyman and economist, wrote essay that Darwin read on his return to England Argued that as population size increases, resources dwindle, the struggle to live intensifies, and conflict increases

15. D ARWIN ’ S T HEORY A population can change over time when individuals differ in one or more heritable traits that are responsible for differences in the ability to survive and reproduce.

16. N ATURAL S ELECTION A difference in the survival and reproductive success of different phenotypes Acts directly on phenotypes and indirectly on genotypes

17. V ARIATION IN P OPULATIONS All individuals have the same genes that specify the same assortment of traits Most genes occur in different forms (alleles) that produce different phenotypes Some phenotypes compete better than others

18. V ARIATION IN P OPULATIONS All individuals have the same genes that specify the same assortment of traits Most genes occur in different forms (alleles) that produce different phenotypes Some phenotypes compete better than others

19. G EOLOGICAL D ISCOVERIES Similar rock layers throughout world Certain layers contain fossils Deeper layers contain simpler fossils than shallow layers Some fossils seem to be related to known species

20. S TRATIFICATION Fossils are found in sedimentary rock This type of rock is formed in layers In general, layers closest to the top were formed most recently

21. Fig. 17-11, p.269 Stratification

22. F OSSILIZATION Organism becomes buried in ash or sediments Organic remains become infused with metal and mineral ions Carbon 14 dating Fig.19.6, p. 309

23. a A simple way to think about the decay of a radioisotope to a more stable form, as plotted against time. after one half-life after two half-lives Fig. 17-12a, p.270 parent isotope in newly formed rock Radiometric Dating

24. Fig. 17-13, p.271

25. C ONTINENTAL D RIFT Idea that the continents were once joined and have since “drifted” apart Initially based on the shapes Wegener refined the hypothesis and named the theoretical supercontinent Pangea

26. C OMPARATIVE M ORPHOLOGY Study of similarities and differences in body plans of major groups Puzzling patterns: Animals as different as whales and bats have similar bones in forelimbs Some parts seem to have no function

27. C OMPARATIVE M ORPHOLOGY Comparing body forms and structures of major lineages Guiding principle: When it comes to introducing change in morphology, evolution tends to follow the path of least resistance

28. Fig. 17-17, p.274 Morphological Divergence  Change from body form of a common ancestor  Produces homologous structures

29. 1 2 3 c chicken Fig. 17-17c, p.274 Morphological Divergence

30. 4 e Porpoise 1 3 2 5 Fig. 17-17e, p.274 Morphological Divergence

31. g Human 5 4 3 2 1 Fig. 17-17g, p.274 Morphological Divergence

32. M ORPHOLOGICAL C ONVERGENCE Individuals of different lineages evolve in similar ways under similar environmental pressures Produces analogous structures that serve similar functions

33. Fig. 17-18a, p.275 Morphological Convergence

34. Fig. 17-18b2, p.275 Morphological Convergence

35. C OMPARATIVE D EVELOPMENT Each animal or plant proceeds through a series of changes in form Similarities in these stages may be clues to evolutionary relationships Mutations that disrupt a key stage of development are selected against

36. S IMILAR V ERTEBRATE E MBRYOS Adult shark Early human embryo Two-chambered heart Aortic arches Certain veins

37. C OMPARATIVE B IOCHEMISTRY Kinds and numbers of biochemical traits that species share is a clue to how closely they are related Can compare DNA, RNA, or proteins More similarity means species are more closely related

38. p.278 Comparative Biochemistry Comparative Biochemistry

39. N UCLEIC A CID C OMPARISON Use single-stranded DNA or RNA Hybrid molecules are created, then heated The more heat required to break hybrid, the more closely related the species

40. C OMPARING P ROTEINS Compare amino acid sequence of proteins produced by the same gene Human cytochrome c (a protein) Identical amino acids in chimpanzee protein Chicken protein differs by 18 amino acids Yeast protein differs by 56