Evolution

1. Evolution

2. Introduction Science vs. non-science Common Misconceptions Definition of evolution

3. Who? What? When? Where? Why? How? Is there a force (God) governing evolutionary processes? What is evolution? When has evolution occurred? Where has evolution occurred? What is the motivation behind evolution (if it is governed by God)? How can biodiversity be explained by evolution? Evolution & Science vs. Non-Science Let’s eliminate the Non-Science …factual (evidence) …factual (evidence) …factual (evidence) ...evolutionary theory

4. The differences between the two can be accounted for in the approach; life’s diversity is one topic viewed from two different perspectives.

5. Evolution is NOT: the idea that people are descended from monkeys “EVILution” / science vs. religion an idea created by Charles Darwin Darwin contributed the theory of natural selection as a model for HOW evolution takes place an organism gaining a trait and passing it on to its offspring Logic and genetics refute this position What is evolution?

6. Evolution IS: any change in traits • within a group of organisms • over multiple generations • which has been confirmed by biological studies Science is not asking IF evolution happened, or IF it is happening. Science is searching for evidence to support an evolutionary picture of biodiversity.

7. Evolution Unit Overview History of Evolutionary Theory Evidence Supporting Evolutionary Theory History of Life Patterns in Evolution

8. I. History of Evolutionary Theory Ch 10.1-10.3, Ch. 12 • Earlier published scientists (all in 1700s): • Linnaeus: grouped organisms according to similarities

9. Georges Louis Leclerc de Buffon: species shared ancestors; rejected idea of 6000 yr-old Earth • Erasmus Darwin: all from common ancestor; more complex arises from less complex

10. Hutton (mid-late 1700s) & Lyell (early 1800s): • An ancient, slowly changing Earth • Earth is millions of years old • the processes that changed Earth in the past are the same processes that operate in the present

11. Darwin’s conclusion from Hutton/Lyell: : (mid 1800s) • If the earth could change, then so could the life which depends on the earth. • Life changes in response to a changing environment. • Such a change, however, would take many years (that’s why the earth’s age is significant).

12. Lamarck’s (1809)Theory of Evolution: • By selective use or disuse of organs, organisms either acquired or lost certain traits during their lifetime. • Acquired traits would then be passed on to the next generation • e.g.—fiddler crab, giraffe, duck

14. Lamarck’s Theory of Evolution:Inheritance of Acquired Characteristics

15. Darwin’s conclusion from Lamarck: (mid 1800s) • Organisms can pass only inherited traits. • For example, in artificial selection, humans can select the most beneficial traits (selective breeding) • There are differences in populations across time and even across geographic regions. • …but how?

16. D. Malthus (early 1800) Population Growth: If the human population continued to grow unchecked, sooner or later there would be insufficient space and food for all

17. Darwin’s conclusion: (mid 1800s) • Other animals and plants reproduce in greater numbers than humans; their populations were not overrunning the world • There must be factors that determine whether or not organisms survive and or reproduce

18. Hutton & Lyell: Lamarck: Early scientists: Malthus: Darwin

19. Hutton & Lyell: Lamarck: ancient earth acquired traits Early scientists: Malthus: population growth past vs. present organisms Darwin Natural Selection

20. E. Darwin’s Case Ideas in Darwin’s book, On the Origin of Species: • Variation in populations is a major feature of life • new traits are the result of spontaneous mutations • the variation must already be present before the population experiences a challenge • natural selection acts on existing variation

21. (overproduction) • Large numbers in a population are trimmed by competition for resources • there is a struggle for existence based on the natural competition within a population • as in artificial selection, “good” traits are passed to the next generation • difference: natureselects the survivors… survival of the fittest

22. (adaptation) • Variations that favor reproductive potential will be passed to future generations • Reproducing or Surviving = passing on the traits that made the survivors successful • Fitness: how well-suited an organism is to compete in its environment • Birds select beetles animation

23. (descent with modification) • Favorable variations can be inherited • over time, the characteristics in a population change in response to a changing environment • species today have different traits than past organisms (…because they lived under different circumstances) • Implication: living things are related to each other (a single ‘family tree’ of life)

25. Peppered Moth Example of an organism affected by Natural Selection Prior to 1848, was the dominant species of moth Typica species

26. By 1895, 98% of the moths were this species Carbonaria species

27. An example of natural selection

30. Evolution in Resistance Explanation of how resistance happens: http://www.sumanasinc.com/scienceinfocus/sif_antibiotics.html Explanation of how bacteria transmit resistance: http://survivalrivals.org/the-x-bacteria/animation Video about antibiotic resistance: http://www.youtube.com/watch?v=W-WumllRPLI

31. Evolution in Resistance Summary • Bacteria possess a natural immunity to some antibiotics. • The immune ones survive and reproduce. • The successive generations possess increasing percentages of the immunity. • New drugs push the selective pressure toward more resistant bacteria.

32. Relate Adaptations to Changes in Organisms • Apply the concept of natural selection to the following new terms (see adaptation tables). • Define the terms (first column) • Relate these traits to (a) increased survival OR (b) reproductive success (second column)

33. II. Evidence Supporting Evolutionary Theory Ch. 10.4-10.5 • Fossils • types of fossils found in certain rock layers but not others • fossil organisms in older layers of rock are more primitive

34. B. Geography • Birds on Galapagos were similar—but not identical—to those on South American continent • Darwin hypothesized that island species originated from a common ancestor that migrated from the mainland

36. C. Embryology

37. D. Anatomy Homologous and Analogous Structures Analogous Structures - structures that can be explained by a shared way of life • functional requirement

38. Ex. Wings – bats, birds, and insects

39. Ex. Body shape of sharks, dolphins and whales

40. Analogous structures: • Look similar on the OUTSIDE • Do not look similar on the inside • Are not evidence of common ancestry • Could be evidence of similar selective pressures in the environment

41. Homologous Structures - structures that are similar in origin but not necessarily similar in function

42. Ex. limbs of various animals Turtle Alligator Bird Mammals Typical primitive fish

43. Ex. 5 digit limbs of various animals

44. Homologous structures: • Do not necessarily look similar on the OUTSIDE • Do look similar on the inside • Are evidence of common ancestry • Could be evidence of DIFFERENTselective pressures in the environment

45. Vestigial Structures • structures that are present but are not always used Ex: whales and snakes have pelvic girdles but have no hind limbs

46. Ex. Human appendix What would it take for the appendix to evolve completely out of the human population?

47. E. Molecular Data DNA sequence Analysis & Protein Comparisons

48. III. History of Life Ch. 12 Spontaneous Generation: the idea that living things can spontaneously exist from non-living matter

49. Redi’s Experiment on Spontaneous Generation OBSERVATIONS: Flies land on meat that is left uncovered. Later, maggots appear on the meat. HYPOTHESIS: Flies produce maggots. PROCEDURE Uncovered jars Covered jars Controlled Variables: jars, type of meat, location, temperature, time Several days pass Manipulated Variables: gauze covering that keeps flies away from meat Responding Variable: whether maggots appear Maggots appear No maggots appear CONCLUSION: Maggots form only when flies come in contact with meat. Spontaneous generation of maggots did not occur.

50. Spallanzani’s Experiment Gravy is boiled. Flask is open. Gravy is teeming with microorganisms. Flask is sealed. Gravy is free of microorganisms. Gravy is boiled.