1. Unit VI - Evolution ~ a unifying theme of biology ~

2. Bell Ringer Page 128 –Evolution of the Cell Phone –Cut out the the cell phones and glue them in order  1 st to most present –Discuss the evolution of technology

3. Target Explain Miller & Urey’s experiment and describe how it related to organic molecules Explain how Redi’s & Pasteur’s experiments disproved Abiogenesis

4. Introduction to Evolution PG 129 What does biological “evolution” mean? –Change in organisms over time How does this relate to the “origin of life”? –It doesn‘t…two different topics! –Much more evidence to support evolution –Remember: science deals with natural world, not belief

5. Introduction to Evolution How could “life” have started? –Old Idea: Abiogenesis “spontaneous generation” (abiogenesis)…no nliving matter makes living Disproved by Redi and Pasteur –New Idea: Biogenesis “biogenesis”…life comes from life

6. Introduction to Evolution So, then where did the first cells come from? –H, C, N, S (Hydrogen, Ammonium, Methane) –Early earth Very hot; volcanoes; violent storms/lightning –Miller & Urey experiment Under early earth conditions, organic compounds form & group together into “protocells” (a self- organized, endogenously ordered, spherical collection of lipids proposed as a stepping- stone to the origin of life.)

7. Introduction to Evolution But, when did we actually get cells? And how? –Evidence of first cells 3.4 bln yrs ago Most likely anaerobic bacteria (no O 2 in air) –First photosynthetic cells 2.8 bln yrs ago Increased O 2 in atmosphere Led to ozone layer that protects from UV rays = more cells Aerobic cells could now develop

9. Recap 8-1 Evolution- change in organisms over time Evolution related to “origin of life: they are two different topics, more evidence to support evolution, science deals with NATURAL WORLD not BELIEF Abiogenesis- old idea where non-living matter made living) spontaneous generation Biogenesis- new idea where life comes from life Miller & Urey- under early conditions, organic compounds form & group together into “protocells”

10. Bell Ringer On page 130: Compare and Contrast Redi’s & Pasteur’s experiments Pick up your paper and go to a lab table groups of 4-5 per table Find the years, explain the experiments, include if they had more groups then your paper shows and draw/explain if it does Be prepared to discuss with the class!

11. Target Describe the assumptions that Darwin made in forming the theory of natural selection List examples of indirect evidence that support the theory of natural selection

12. Darwin’s Idea PG 131 How did Darwin form ideas about evolution? –Fossils showed organisms changed over time

13. Darwin’s Idea How did Darwin form ideas about evolution? –Geologists showed that earth was very old

14. Darwin’s Idea How did Darwin form ideas about evolution? –Malthus noticed populations grow faster than their food supplies (they produce too many offspring)

15. Darwin’s Idea How did Darwin form ideas about evolution? –Artificial selection is the idea that breeders could cause major changes in the features of plants and animals over a course of decades

16. Darwin’s Idea How did Darwin form ideas about evolution? –He saw diverse species (ex: finches on Galapagos Islands, all with variations)

17. Adaptive Radiation is a process in which organisms diversify rapidly into a multitude of new forms, particularly when a change in the environment makes new resources available, creates new challenges, or opens new environmental niches.

18. Darwin’s Ideas What did Darwin conclude about species? –He identified that populations change due to “natural selection” (nature selects who goes on)

19. Darwin’s Ideas What did Darwin conclude about species? –Four assumptions: Populations produce large #’s of offspring (more than can survive with given food) Individuals in population have variations Certain variations are more useful (these will survive better) Over time, “good” genes prevail in the population, while “bad” ones fade out

20. Evidence for Evolution What direct evidence supports this theory? –Not much because we have not lived long enough, but some examples: Ex: peppered moth

21. Evidence for Evolution What direct evidence supports this theory? –Structural adaptations Ex: -mimicry – organisms resemble another organism -Camouflage – blending with the environment

22. Evidence for Evolution What direct evidence supports this theory? –Physiological changes Ex: drug-resistant bacteria; Ex: pesticide-resistant insects

23. Recap! 8-2 Darwin’s ideas  fossils, geology, population studies, artificial selection, diversity of species Natural selection  based on four assumptions Evidence that supports this theory  not much, some exps are: peppered moths, structural adaptations, physiological changes

24. Bell Ringer Charles Darwin & Alfred Wallace –Read the paper given, do not write on it –On Page 132 reflect on the paper What are the main ideas of the paper What are the main organisms they talked about What are the pre-Darwinian ideas of evolution What is pressure of population growth What is significant about pigeon breeding What is origin of species

25. Target Recognize examples of analogous, homologous, and vestigial structures Explain why individuals cannot evolve, but populations can evolve

26. Evidence for Evolution PG 133 Is there indirect evidence of evolution? –Fossils show changes through time

27. Evidence for Evolution Is there indirect evidence of evolution? –Anatomy Homologous structures –Similar origin/structures, but may now have different function –Shows common ancestry –Ex: bat wing, whale flipper, human arm

28. Evidence for Evolution Is there indirect evidence of evolution? –Anatomy Analogous structures –Similar function, but very different structure –Shows separate development…not related –Ex: bird wing & butterfly wing

29. Evidence for Evolution Is there indirect evidence of evolution? –Anatomy

30. Evidence for Evolution Is there indirect evidence of evolution? –Anatomy Vestigial structures –A part that no longer serves a purpose –Ex: snake hip bones; human wisdom teeth

31. Bell Ringer Vote for the BEST Creature –You cannot vote for your own –Vote on adaptations, and features

32. Evidence for Evolution Is there indirect evidence of evolution? –Embryology Early similarities may show relation

33. Evidence for Evolution Is there indirect evidence of evolution? –Embryology Early similarities may show relation

34. Evidence for Evolution Is there indirect evidence of evolution? –Embryology

35. Evidence for Evolution Is there indirect evidence of evolution? –Biochemistry Similar chemicals in most life forms (DNA, ATP) More similarities in code means closer relationship

37. Mechanisms of Evolution Can individuals evolve? –No! –Genes are genes…cannot alter them* –Only populations can evolve –Gene pool = sum of all genes in population

38. Recap! 8-3 Fossils- show change over time Homologous structures- similar structure, different function Analogous structures- similar function, different structure Vestigial structures- a part that no longer serves a purpose Embryology-early similarities showing relation Biochem-DNA, ATP, Codes with simiarities Populations evolve, not individuals!

39. Bell Ringer PG 136 An organism that is the fittest: A.Has the best adaptations to survive & reproduce in its environment B.Has the ability to hide from its predators in the best manner possible C.Is the strongest & therefore the best able to kill its prey D.Is the youngest & therefore the most active Structures that have a similar evolutionary origin & structure but are adapted for different purposed, such as the bat wing and a human arm, are called_________.

41. Mechanisms of Evolution PG 135 How do populations evolve? –Any factor that affects genes in gene pool may disrupt equilibrium…leads to change (evolution) –Mutations may cause a shift –Genetic variations may cause changes…especially in small isolated populations…change to concentrate recessive traits much higher –Genetic drift – immigration/emmigration into or out of population –Large populations not as affected by these factors

42. Mechanisms of Evolution How do species evolve? –Called “speciation” (same species can breed) –Geographic isolation A barrier like river, road, mountain, etc. that keeps individuals apart so they cannot interbreed…over time they develop different traits (Ex: finches on different parts of the island)

43. Mechanisms of Evolution How do species evolve? –Called “speciation” (same species can breed) –Geographic isolation

44. Mechanisms of Evolution How do species evolve? –Called “speciation” (same species can breed) –Reproductive isolation no longer capable of interbreeding (timing, parts, gametes differ,…)

45. Modes of Selection

46. Directional Selection Pushes toward ONE extreme or the other Ex: in dry years, beak size pushed to larger

47. Mechanisms of Evolution Does evolution show patterns? –Convergent evolution- distantly related organisms with similar traits

48. Disruptive Selection Pushes toward both extremes Ex: small beak for soft seeds; large beak for hard seeds; medium beak is bad at both types of seeds so selected against

49. Stabilizing Selection Pushes to average Ex: cactus with few spines eaten by animals more; cactus with too many spines invaded by more parasites

50. Three Types of Selections

51. Mechanisms of Evolution PG 137 How fast can species evolve? –Gradualism Species start up over long time with gradual changes (millions of years) –Punctuated equilibrium Speciation occurs in quick bursts with equilibrium in between (~10,000 yrs or less)

52. Mechanisms of Evolution How fast can species evolve?

53. Mechanisms of Evolution Does evolution show patterns? –Divergent evolution Ancestral species evolves into many species that fit different habitats Ex: finches; common on islands

54. Mechanisms of Evolution Does evolution show patterns? –Convergent evolution Distantly related organisms end up with similar traits Occurs when have similar habitats Ex: cactus in S. American & African deserts

56. Quiz – Evolution for use with Questions 1 & 2

57. Quiz – Evolution for use with Questions 3-5

58. Quiz – Evolution for use with Question 6

59. Quiz – Evolution for use with Question 7