Welcome to Evolution 101 Reading Guide

Transcription

1 Name: Welcome to Evolution 101 Reading Guide Read the information on the website. Click on the next arrow at the bottom of each page to move to the next page. As you read, complete the questions below. AN INTRODUCTION TO EVOLUTION 1. Define the term evolution. 2. In the fall, trees change as they lose leaves. Why is this process not an example of evolution? THE HISTORY OF LIFE: LOOKING AT THE PATTERNS 3. What is the central idea of evolution? 4. Define phylogeny. 5. List the three main clades/domains. 6. On the phylogeny below, use a cross to identify the common ancestor of 2, 3, and 4. With a circle, identify the unique ancestor of Define clade. 8. Draw a clade on the picture above.

2 9. What are the three things one needs to keep in mind when reading phylogenies? 10. What are the two common misconceptions about humans? 11. Give two examples of shared derived characters that biologists study when building phylogenies. 12. What is a homologous character? Give an example. 13. What is an analogous character? Give an example. 14. Which structures show a common origin, homologous or analogous? 15. List three purposes of phylogenetic trees: 16. Why are birds dinosaurs? 17. If you wanted to squeeze the 3.5 billion years of the history of life on Earth into a single minute, when would modern humans evolve? 18. What are the three common methods scientists use to put dates on events?

3 19. Using the timeline, determine how many mya mammals and dinosaurs evolved. MECHANISMS: THE PROCESS OF EVOLUTION 20. Which example illustrates changes in gene frequency, beetles on a diet or beetles of a different color? 21. List the four processes that are the basic mechanisms of evolutionary change. 22. Name three common causes of genetic variation. 23. True or False? Mutations are changes in DNA. Mutations are random. Somatic mutations matter to evolution. Germ line mutations matter to evolution. 24. What are two common causes of mutations? 25. What is gene flow and why is it important? 26. Why are siblings not genetically identical to each other and to parents? 27. Define morphology. 28. How is genetic drift different from natural selection? 29. Use the steps of natural selection listed below to explain how natural selection takes place. Use an example that is not described on the webpage (something different than beetle color). There is variation in traits There is differential reproduction

4 There is heredity End result 30. What is fitness? 31. Give an example of sexual selection. 32. How is artificial selection different from natural selection? 33. List one adaptation of the creosote bush. 34. Define vestigial structures and give one example. 35. Why are need, try, and want not accurate words for describing the process of evolution? 36. Is natural selection a random process? Why or why not? 37. Describe the case study of coevolution squirrels, birds, and pinecones they love. MICROEVOLUTION 38. Define microevolution. 39. True or false? A change in gene frequency over time means that the population has evolved.

5 40. List the four mechanisms of microevolution. SPECIATION 41. Define species. 42. Explain why the definition of species does not apply to all organisms. 43. Paraphrase how speciation of fruit fly (Drosophila) is thought to have occurred. 44. What are two common causes of speciation? 45. List three barriers to gene flow that may contribute to speciation. 46. Define allopatric speciation and provide two sources of evidence that support this type of speciation. 47. Give an example of cospeciation. MACROEVOLUTION 48. Define macroevolution.

6 49. List the four major mechanisms of macroevolution. 50. Why do the mechanisms listed in question 49 seem familiar? 51. In addition to the mechanisms listed in question 49, what else is needed for macroevolution to take place? 52. Label the following patterns of macroevolution. THE BIG ISSUES 53. What should we observe in the fossil record if evolution is slow and steady? 54. What would we observe in the fossil record if evolution happens in "quick" jumps? 55. Why would one lineage lead to millions of species and the other to only 400? 56. Explain the sentence: Evolution produces a tree, not a ladder and we are just one of many leaves on the tree.