1. Evolution is a Theory! A theory is a well supported explanation of a phenomena that has occurred in the natural world A theory in science is a well tested, well supported hypothesis, not just a guess

2. Evidence of Evolution 1.Fossil Record 2.Geographic Distribution of Living Species 3.Homologous Body structures 4.Similarities in Embryology

3. Evidence of Evolution Fossil Record provides evidence that living things have evolved Fossils show the history of life on earth and how different groups of organisms have changed over time

4. Fossil Formation 1. Ammonite is alive and swimming 2. Ammonite dies and sinks into the sediments 3. Soft body decays, leaving shell (or bones) 4. Minerals gradually replace the bone/shell

5. Relative vs. Absolute Dating

6. Relative Dating Can determine a fossil’s relative age Performed by estimating fossil age compared with that of other fossils Drawbacks – provides no info about age in years

7. Absolute dating Can determine the absolute age in numbers Is performed by radioactive dating – based on the amount of remaining radioactive isotopes remain Drawbacks - part of the fossil is destroyed during the test

8. Carbon-14 Dating

9. Primate Fossils AustralopithecusHomo erectusHomo sapien

10. Primate Brain Capacity

11. Primate Bone structure

12. Human Relatives

13. Australopithecus afarensis

14. Homo habilis = handy human 1.5 to 2 mya Homo erectus 1.6 mya bipedal

15. Neanderthals 35,000 to 100,000 ya Cro-Magnon 35,000 to 40,000 ya

16. 2.Geographic Distribution of Living Species Similar animals in different locations were the product of different lines of descent Evidence of Evolution

17. Adaptive Radiation

18. Turtle Alligator Bird Homologous Body Structures Structures that have different mature forms but develop from the same embryonic tissues e.g. Wing of bat, human arm, leg of turtle Evidence of Evolution

19. Homologous Body Structures

20. Vestigial Organs –traces of homologous organs in other species –Organ that serves no useful function e.g. Appendix

21. Evidence of Evolution Similarities in Embryology –In their early stages of development, chickens, turtles and rats look similar, providing evidence that they shared a common ancestry.

22. Mechanisms for evolution Do populations or individuals evolve? What is a gene pool? How do populations change?

24. Mechanisms for evolution Do populations or individuals evolve? What is a gene pool? How do populations change? Would these types of change effect a large or small population more?

25. WHAT IS SPECIATION? A single species becomes multiple species. Can result from: - Geographical isolation

26. SPECIATION GEOGRAPHIC ISOLATIONGEOGRAPHIC ISOLATION REPRODUCTIVE ISOLATIONREPRODUCTIVE ISOLATION

27. Coevolution Organisms evolve in response to each other. –For every defense mechanism a prey species develops, a predator develops a way around it. –Pollinators become more and more specialized to the plants that they pollinate.

34. Convergent evolution Unrelated organisms evolve similar structures. What were these structures called?!? Homologous structures

38. Form Fits Function Organisms will change over time to become more and more efficient. Their physical structures will become increasingly suited to their specific tasks.

41. Evolution