DO Now

2. DO Now • What is Evolution? • What is genetic variation? • What is struggle of the fittest? • What is natural selection? • How do animals evolve: use genetic variation, struggle of the fittest and natural selection in your answer.

3. Wednesday, November 20, 2013 Your Learning Goal: Students will be able to defend the theory of evolution using homologous structures as their evidence. Standard 3c:Students know independent lines of evidence from geology, fossils, and comparative anatomy provide the bases for the theory of evolution Table of Contents:3.10 Evolution Defense Homework: Homologous structures as evidence for evolution Agenda: • Do-Now • Homologous notes • Are these animals homologous • Work on HW

4. Why do you think birds and bats both have wings?

5. Why do you think birds, reptiles, amphibians, and mammals all have lungs? (fish don’t)

6. Comparative Anatomy

7. Comparative Anatomy • Comparative anatomy looks at the similarities and differences in the anatomy of organisms, and how these structures are used. • The anatomy is the way the body is designed: bone structure and organ structures. • Comparing the way organisms are put together

8. Homologous structures • Homologous Structures- Body structured that are similar in different species because the species have common descent. The structure was evolved from a shared ancestor • Common Descent: They evolved from the same ancestor • The structures may or may not perform the same function. • Homologous structures provide evidence of evolution because these structures are too similar to be coincidence and have been adapted for the different environments of the different animals.

9. Vertebrate Limbs & Common Ancestor

10. Human Human Human Human Human Human A A A Human B B Lizard Lizard Lizard Lizard Lizard Lizard Lizard Lizard Lizard Octopus Octopus Octopus Octopus Octopus Bird Whale Grasshopper Which limb is not homologous? Why?

11. Comparative Anatomy: Homologous structures • For example: same bone structure found in a human arm, bat wing, whale flipper, and cat leg…

12. The gene to signal the formation of eyes is homologous for humans and insects. What do you think will happen if you replace the insect eye gene with the human eye gene?

13. The eye gene to create eyes is homologous, it was evolved by a common ancestor. If you switch the human eye gene for the insect eye gene the insect will still grow an eye.

14. Can Genes be Homologous?

15. Vestigial Structures • Vestigial Structures: Homologous structures present in an organism that has lost its function. • These structures don’t do what they were originally evolved to do • Evidence of evolution because animals had them and evolved to not use them • Examples: • Whales have leg bones buried in the back of their bodies • Human appendix is vestigial to an organ used to digest cellulose in primitive ancestor

16. Theory of Whale evolution:

19. Other vestigial Examples • Wings on flightless birds • Human tail bone • Wisdom teeth in humans

20. Analogous Structures • Analogous structures: structures that have similar look and/or functions in different species, but do not share a common descent • The two structures evolved separately and are unrelated • For example: • Wings of insects vs. wings of birds vs. Bats

21. Why do you think animals evolve analogous structures separately

22. Why do you think animals evolve analogous structures separately • The environments could have similar qualities with similar struggles. In both environments, the similar analogous structure was the best and naturally selected to become adaptations.

23. 1. Are all of these different leaves Homologous?

24. 2. Wings of a bat and a robin?

25. Fish Amphibians Reptile Mammals Bird And scales!

26. 3. Scales on a brown trout and a lizard?

27. Fish Amphibians Reptile Mammals Bird And scales!

28. 4. Front teeth on a beaver and the tusks on an elephant?

29. 5. Wings of a dragon fly and the wings of a butterfly?

30. 6. The limbs of an eagle and the limbs of a penguin?

31. 7. Fins of a shark and the fins of a dolphin?

32. Fish Amphibians Reptile Mammals Bird And scales!

33. 8. No limbs on a water snake or an eel?

34. Fish Amphibians Reptile Mammals Bird And scales!

35. 9. Opposable thumbs of the bush baby and the human?

36. 10. Gliding adaptation of the marsupial sugar glider from Australia and the placental gliding squirrel of the Americas?

38. Answers • Yes • No • No • Yes • Yes • Yes • No • No • Yes • No

39. What do you call the structures that were similar that were not homologous

40. What’s the difference between the homologous and analogous structures?

41. Homologous structures evolved from a common ancestor. The two different species received the structure from the same ancestor. Analogous structures evolved separately because of natural selection. The structures are unrelated.

42. Evolution of the bird • The bird evolved from 4 legged dinosaurs that walked on their hind legs. One of the ancestors include the velociraptor

43. Are birds more related to the pterodactyl, a flying dinosaur, or the velociraptor, a dinosaur that could not fly? And why?

44. Birds are more related to the velociraptor because birds evolved from velociraptors and did not evolve from pterodactyls. The wings of a pterodactyl and a bird are analogous. They were separately naturally selected.

45. Reasoning 1: How do homologous structures prove evolution? Evidence 1: Homologous structures: What are homologous structures? Reasoning 2: How do vestigial structures prove evolution? Evidence 2: Vestigial structures: What are vestigial structures? Claim Evolution exists Evidence 3: Analogous structures: What are analogous structures? Reasoning 1: How do analogous structures prove evolution

46. Reasoning 1: How do homologous structures prove evolution? Evidence 1: Homologous structures: What are homologous structures? Reasoning 2: How do vestigial structures prove evolution? Evidence 2: Vestigial structures: What are vestigial structures? Claim Evolution exists Evidence 3: Analogous structures: What are analogous structures? Reasoning 1: How do analogous structures prove evolution