1. Natural Selection 303

2. What is a scientific theory? o http://www.pbs.org/wgbh/evolution/library/1 1/2/e_s_1.html http://www.pbs.org/wgbh/evolution/library/1 1/2/e_s_1.html

3. Theory Freewrite What is your scientific definition of a theory? How is it different from a law?

4. Scientific Law a statement of scientific fact or phenomenon that is observable

5. Scientific Theory A widely accepted explanation of some aspect of the natural world that can include facts, laws, inferences, and tested hypotheses

6. Theory of Evolution A change in the genetic characteristics of a population from one generation to the next.

7. Your Definition How would you describe the mechanism of natural selection?

8. Premises of natural selection 1.Genetic variation in a population 2.More offspring produced than can survive 3.Individuals most suited to the environment reproduce and pass on gene –“reproduction of the fittest” 4.Over time, beneficial gene becomes more common and population changes

9. Why is “reproduction of the fittest” a better description than “survival of the fittest?” –Fitness = leave the most descendants

10. Acquired Characteristics vs. Natural Selection Variations are purposeful Variations are the result of an organism striving to be better Variations are random Variations due to genetic mutation

13. Natural Selection... is the primary mechanism of evolutionary change changes the genetic make-up of a population is the “survival of the fittest”

14. Natural Selection Examples

15. Using the variation in snail shells (as seen in the picture), make up a scenario in which natural selection might occur in this snail population.

16. A Variety of Beaks Reproductive Isolation

17. Selecting a Variety of Peppered Moths

18. Biogeography http://www.ucmp.berkeley.edu/education/ex plorations/tours/stories/middle/G8.htmlhttp://www.ucmp.berkeley.edu/education/ex plorations/tours/stories/middle/G8.html

19. Biogeography Write down one observation you can make about how the yellow line moves. What is the explanation (inference) for why the same type of tree is found in many parts of the world?

20. Common Ancestor Geographic Isolation

22. Divergent Evolution

23. Explain the following statement... Speciation occurs through divergent evolution.

24. Extinction Extinction is the ultimate fate of all species 99.9% of all the species that have ever existed are now extinct

25. Factors affecting speciation and extinction large-scale movement of the continents gradual climate changes rapid climate changes

26. Speciation - Extinction = Biodiversity

27. Variations in Guppies