1. Evolution Sec. 16.1

2. Darwin and Natural Selection Evolution: Change in a population over time Evolution: Change in a population over time Galapagos Islands: Galapagos Islands: -located off the west coast of South America -Darwin studied species of animals and plants; and found that species varied between islands

3. GALAPAGOS ISLANDS

4. SPECIES VARIATION BETWEEN ISLANDS

5. Mathus Discovered that the human population growth outpaces the food supply Discovered that the human population growth outpaces the food supply

7. Darwin discovered species compete for survival Food Food Space Space Finding mates Finding mates Escaping predators Escaping predators Shelter Shelter

8. SURVIVAL OF THE FITTEST ONLY THE BEST FIT FOR THE ENVIRONMENT SURVIVE TO REPRODUCE! ONLY THE BEST FIT FOR THE ENVIRONMENT SURVIVE TO REPRODUCE!

9. DARWINS DISCOVERIES EACH GENERATION OF NEW SPECIES SHOWS VARIATION IN TRAITS THROUGH: EACH GENERATION OF NEW SPECIES SHOWS VARIATION IN TRAITS THROUGH: 1. ARTIFICIAL SELECTION 2. NATURAL SELECTION

10. ARTIFICIAL SELECTION BREEDING ORGANISMS WITH SPECIFIC TRAITS TO PRODUCE OFFSPRING WITH IDENTICAL TRAITS BREEDING ORGANISMS WITH SPECIFIC TRAITS TO PRODUCE OFFSPRING WITH IDENTICAL TRAITS

11. DOG BREEDING: EX. OF ARTIFICAIL SELECTION

12. NATURAL SELECTION PROCESS OF SELECTION WHICH OCCURS IN NATURE PROCESS OF SELECTION WHICH OCCURS IN NATURE ORGANISMS WITH CERTAIN VARIATIONS SURVIVE, REPRODUCE AND PASS VARIATIONS TO NEXT GENERATION ORGANISMS WITH CERTAIN VARIATIONS SURVIVE, REPRODUCE AND PASS VARIATIONS TO NEXT GENERATION ORGANISMS WITHOUT THESE VARIATIONS ARE LESS LIEKLY TO SURVIVE AND REPRODUCE. ORGANISMS WITHOUT THESE VARIATIONS ARE LESS LIEKLY TO SURVIVE AND REPRODUCE.

13. NATURAL SELECTION

14. Natural Selection:

15. ADAPTATIONS VARIATIONS THAT AID ORGANISMS IN SURVIVAL IN THEIR ENVIRONMENT VARIATIONS THAT AID ORGANISMS IN SURVIVAL IN THEIR ENVIRONMENT Ex: thorns on plants, distinct coloration of animals Ex: thorns on plants, distinct coloration of animals Darwin believed adaptations occurred over many generations. Darwin believed adaptations occurred over many generations.

16. Structural Adaptations Changes in an organisms appearance or physical traits Changes in an organisms appearance or physical traits

17. MIMICRY Structural adaptation that allows one species to resemble another Structural adaptation that allows one species to resemble another Harmless species often adapt to look like harmful to protect themselves from predators Harmless species often adapt to look like harmful to protect themselves from predators

18. CAMOUFLAGE STRUCTURAL ADAPTATION THAT ENABLES SPECIES TO BLEND WITH THEIR SURROUNDINGS STRUCTURAL ADAPTATION THAT ENABLES SPECIES TO BLEND WITH THEIR SURROUNDINGS Prevents species from being seem by predators. Prevents species from being seem by predators.

19. PHYSIOLOGICAL ADAPTATIONS Changes in an organisms metabolic processes Changes in an organisms metabolic processes Ex: penicillin-resistant bacteria; pesticide resistant insects and weeds Ex: penicillin-resistant bacteria; pesticide resistant insects and weeds

20. INDIRECT EVIDENCE OF EVOLUTION Fossils Fossils Anatomy Anatomy Embryology Embryology Biochemistry Biochemistry

21. 1. Fossils Provide record of early life Provide record of early life Ex: Camels Ex: Camels

22. 2. Anatomy Homologous structures: structures with common evolutionary origin Homologous structures: structures with common evolutionary origin - can be similar in structure, function, or both - believed structures are evidence of evolution from an common ancestor

23. Homologous Structures Ex: Forelimbs

24. 2. Anatomy Analogous Structures: features that do not have a common evolutionary origin but are similar in function. Analogous Structures: features that do not have a common evolutionary origin but are similar in function. Ex: Butterfly wing and Bird wing Ex: Butterfly wing and Bird wing

25. Analogous Structures

26. 2. Anatomy Vestigial Structures: structures that have no function now but did in an ancestor Vestigial Structures: structures that have no function now but did in an ancestor A structure becomes vestigial when it is no longer needed. A structure becomes vestigial when it is no longer needed.

27. Vestigial Structure Appendix is no longer used in humans so it is considered a vestigial structure. (need when we ate more of a plant based diet)

28. 3. Embryology Easy to distinguish adult bird and mammal but difficult to distinguish embryos. Easy to distinguish adult bird and mammal but difficult to distinguish embryos. Embryo: earliest stage of growth and development of an organism Embryo: earliest stage of growth and development of an organism Suggest evolution of common ancestors Suggest evolution of common ancestors

29. Embryology

30. 4. Biochemistry Compares DNA and RNA of different species to determine evolutionary relationships Compares DNA and RNA of different species to determine evolutionary relationships

31. MECHANISMS OF EVOLUTION SEC. 15.2

32. POPULATION GENETICS GENE POOL: ALL THE ALLELES OF A POPULAITONS GENES GENE POOL: ALL THE ALLELES OF A POPULAITONS GENES ALLELE FREQUENCY: PERCENTAGE OF A SPECIFIC ALLELE IN A POPULATION ALLELE FREQUENCY: PERCENTAGE OF A SPECIFIC ALLELE IN A POPULATION GENETIC EQUILIBRIUM: WHEN THE ALLELE FREQUENCY REMAINS THE SAME OVER GENERATIONS GENETIC EQUILIBRIUM: WHEN THE ALLELE FREQUENCY REMAINS THE SAME OVER GENERATIONS

33. CHANGES IN GENETIC EQUILIBRUIUM GENETIC DRIFT GENETIC DRIFT NATURAL SELECTION: NATURAL SELECTION: –STABILIZING SELECTION –DIRECTIONAL SELECTION –DISRUTIVE SELECTION

34. GENETIC DRIFT ALTERATION OF ALLELIC FEQUENCIES BY CHANCE EVENTS; COMMONLY OCCURS IN SMALL POPULATIONS ALTERATION OF ALLELIC FEQUENCIES BY CHANCE EVENTS; COMMONLY OCCURS IN SMALL POPULATIONS Ex: Amish Settlement in PA Ex: Amish Settlement in PA –1 in 14 (short arms, legs, extra fingers and toes) –1 in 1000 in US population in general

35. STABILIZING SELECTION Favors average sized individuals Favors average sized individuals Small cannot compete for food; large are seen by predators. SEE #1

36. DIRECTIONAL SELECTION Favors extreme variation Favors extreme variation See #3 Elephants with longer trunks are able to reach food/water more easily.

37. DISRUPTIVE SELECTION Favors either extreme Favors either extreme See #2 Marine Limpets with white, tan and dark brown shells. The white and brown are camouflaged as rocks while tan are easily seen.

39. EVOLUTION OF SPECIES (SPECIATION) SPECIES: Groups of organisms that look alike and can interbreed to produce fertile offspring SPECIES: Groups of organisms that look alike and can interbreed to produce fertile offspring SPECIATION: The evolution of a new species SPECIATION: The evolution of a new species –Occurs when members of a population can no longer interbreed and produce fertile offspring.

40. Geographic Isolation Physical barrier divides population Physical barrier divides population

41. REPRODUCTIVE ISOLAION GENETIC MATERIAL BECOMES TO DIFFERENT TO MATE. GENETIC MATERIAL BECOMES TO DIFFERENT TO MATE. BEHAVIOR: MAY MATE AT DIFFERENT TIMES OF YEAR BEHAVIOR: MAY MATE AT DIFFERENT TIMES OF YEAR POLYPLOIDY: INDIVIDUALS WITH AN EXTRA SET OF CHROMOSOMES CANNOT MATE SUCCESSFULLY POLYPLOIDY: INDIVIDUALS WITH AN EXTRA SET OF CHROMOSOMES CANNOT MATE SUCCESSFULLY

42. REPRODUCTIVE ISOLATION

43. GRADUALISM VS. PUNCTUATED EQQUILBRIUM Gradualism Believes change will happen slowly over many generations Believes change will happen slowly over many generationsPunctuated Change is rapid and then long periods of equilibrium occur between Change is rapid and then long periods of equilibrium occur between

45. PATTERNS OF EVOLUTION Adaptive radiation Adaptive radiation –Ancestors evolve into an array of species to fit the environment Divergent evolution Divergent evolution –Species becomes increasingly distinct from original ancestor Convergent evolution Convergent evolution –Unrelated species that occupy similar environments in different parts of the world undergo similar natural selection

46. ADAPTAVIE RADIATION

47. DIVERGENT EVOLUTION

48. CONVERGENT EVOLUTION