1. EVOLUTION CHAPTER 15

2. Natural Selection & the Evidence for Evolution Ch. 15, Sec. 1

3. Think, Pair, Share… 1) What is evolution? 2) What evidence do scientists have that suggests evolution actually occurs?

4. Evolution Gradual change in a species over time due to adaptations, There are exceptions, not always gradual Science is Tentative Development of new organisms from preexisting types of organisms Living things come from other living things New species come from other species

5. Characteristic changes in a population involve changes to genes These changes then get passed along through the genes 3) Who do you get your genes from? Supported by a lot of evidence and data Fossil, Anatomical, & DNA

7. Biology 4/21/14 Mrs. Turgeon “Education is learning what you didn’t even know you didn’t know.” –Daniel J. Boorstin DO NOW: Imagine an organism that lives in oceans. Describe one adaptation that the organism might have for that environment. AGENDA: SWBAT understand the theory of evolution by taking notes HOMEWORK: T Notes 15.1 and 15.2 due Friday, April 25

8. Charles Darwin (1809-1882) Started off studying medicine 1831 signed on for a 5 year journey of South America on the HMS Beagle Enjoyed nature & making observations Noticed similar looking organisms on different continents

10. Darwin’s Clues Collected fossils Observed the adaptations of plants & animals allowing them to survive in particular environments Adaptation = a trait (which is coded for by DNA in a gene) that allows an organism to be successful in its environment Like tools that help them get the job done

11. 4) How are these organisms adapted to their environment?

12. Galapagos Islands One of Darwin’s stops on the Beagle Group of volcanic islands off the west coast of South America

13. Home to several species of finches Each species is adapted to the type of food eaten 5) Would the warbler finch be able to eat what the Large Ground finch can eat? Why or Why not?

14. Darwin’s Hypotheses Darwin hypothesized that all the species descended from ancestral finches The ancestral finches flew to the Galapagos Islands from mainland South America Population changed over time to adapt to the specific environment of their island

15. Biology 4/25/14 Mrs. Turgeon “Vitality shows in not only the ability to persist but the ability to start over”- F Scott Fitzgerald DO NOW: Pass forward your HW: T Notes 15.1 and 15.2. AGENDA: SWBAT understand the theory of evolution by taking notes & watching a video

16. Biology 4/28/14 Mrs. Turgeon “Better be wise by the misfortunes of others than by your own.” - Aesop DO NOW: 1. Get out your video guide from Friday 2. In your notes: describe the 3 observations that Darwin made during his research AGENDA: SWBAT understand the theory of evolution by taking notes & watching a video

17. Darwin’s Observations 1. Overproduction Most species produce large numbers of offspring (ex: rabbits) 6)But why isn’t the earth overrun by rabbits? The environment will set a limit on how big the population gets by causing deaths or limiting births 2. Individuals within a population compete with one another

18. Observations cont. 3. Genetic Variation Within populations organisms have different traits because of variations in genes Variations can be inherited 7) Did you inherit any interesting variations? Populations have multiple alleles for any given trait (dark fur/light fur, tall ears/short ears, etc.)

19. In summary… Organisms that have superior traits/tools are better adapted Therefore they’re more likely to survive Therefore they’re more likely to reproduce and pass on the genes for the superior traits/tools 8) What “chooses” the superior traits?

20. Artificial Selection Darwin worked with breeding different variations on pigeons Artificial Selection = humans select good traits in organisms to breed Ex: prettier roses, bigger chickens, sweeter oranges YOU see it all the time Darwin hypothesized: Something like Artificial Selection must be acting on the organisms living in the wild

21. Natural Selection Natural Selection = mechanism for change in populations; organisms with favorable variations survive, reproduce, & pass on the variation to the next generation (offspring) Organisms with the best adaptations (helpful traits, good “tools”) are most likely to survive & reproduce Through inheritance the adaptations will become more frequent in the population

22. Who gets to evolve? 9) Can YOU evolve? Why or why not? It is the population that evolves, not the individual 10) If you like swimming, can you choose to evolve gills? An individual can be born with a mutation If the mutation is an advantage (good “tool”) for living in a particular environment then that individual will be more likely to survive & pass on that mutation to its offspring Evolution Videos Field\Natural_Selection_512k.wmv

24. Structural Adaptations Why are these structures adaptations?

25. Biology 4/22/14 Mrs. Turgeon “One cannot and must not try to erase the past merely because it does not fit the present.” DO NOW: Imagine an organism that lives in oceans. Describe one adaptation that the organism might have for that environment. AGENDA: SWBAT understand the theory of evolution by taking notes HOMEWORK: T Notes 15.1 and 15.2 due Friday, April 25

26. Mimicry = structural adaptation allowing one species to resemble another species

27. Camouflage = adaptations allows species to blend in with surroundings

28. Rapidly Developing Physiological Adaptations Evolution is not always a slow process Evident in antibiotic resistance (bacteria evolve too)

29. Resistance of insects to pesticides

30. Increased toxicity of snake poison

31. Fossil Evidence Fossils show that over time species forms have gradually changed A transitional species will have characteristics of both the ancient and modern organism there has to be something in between Ex: Do children automatically become adults? Ex: Modern whales evolved from an ancient, land mammal

34. Anatomical Evidence Studying anatomy can uncover structural evidence of a common ancestor Homologous Structure = similar in build, different function; anatomical structures in different species inherited from a common ancestor

35. An early ancestor of all 4 species had a forelimb with similar structure (common ancestor)

36. Analogous Structures = have closely related functions, but are built differently; does not indicate a common ancestor

37. Vestigial Structures = serve no function but resemble structures with functional roles in other animals

38. Embryology Embryology = the study of how organisms develop Early stages of vertebrate embryos look very similar As development continues embryos of different species start looking less alike

40. DNA Evidence All living organisms have DNA in common DNA codes for proteins The more closely related two species are…. The more similar their DNA…. The more similar the proteins made in their bodies are

41. Mechanisms of Evolution Ch. 15, Sec. 2

42. Population Genetics Gene Pool = all the alleles for a particular trait in a population are “pooled” together ex: all the alleles for short fur and long fur, all the alleles for brown fur and black fur Allelic Frequency = percentage of a specific allele in the gene pool % of brown fur alleles & % of black fur alleles Genetic Equilibrium = maintaining the same frequency of alleles over time

43. Changes in Genetic Equilibrium Mutations can cause variations to be added to the gene pool of a population Genetic Drift = chance events changing a population’s genetic equilibrium

44. Natural Selection Acts on Variations Stabilizing selection = natural selection that favors average individuals in a population

45. Directional selection = natural selection favors one of the extreme variations of a trait

46. Disruptive selection = individuals with either extreme of a trait’s variation are selected for

47. Evolution of a Species Changes to a gene pool can lead to the evolution of a new species Speciation = members of similar populations can no longer interbreed

48. Geological Isolation = physical barriers divide a population  Over time, the  divided populations may become two species that can no longer interbreed, even if reunited Evolution Videos Field\Biogeography_512k.wmv Evolution Videos Field\Biogeography_512k.wmv

49. Reproductive Isolation = occurs when formerly interbreeding organisms can no longer mate and produce fertile offspring; 2 types 1. Genetic Isolation = genes of two populations are so different they cannot produce fertile offspring 2. Behavioral isolation (ex: one population mates in the spring, another population mates in the fall)

50. Change in Chromosome Numbers = mistakes in cell division lead to polyploid individuals (abnormal sets of chromosomes) Polyploids can be sterile, unable to reproduce Polyploids can also reproduce and generate a new species through interbreeding

51. Speciation Rates Gradualism = species originate through gradual change of adaptations Punctuated Equilibrium = speciation occurs in quick, rapid bursts

53. Patterns of Evolution Divergent Evolution = species that were once similar evolve to look differently Adaptive Radiation = ancestral species evolving to fit into a lots of different habitats

54. Convergent Evolution = very distantly related organisms evolving similar traits Evolution Videos Field\Convergent_256k.wmv

56. Hummingbird moths are night-flying insects whose behavior and appearance are similar to those of hummingbirds. Explain how these two organisms demonstrate convergent evolution and analogous structures. (1 paragraph, 5-8 sentences)