1. Evolution & Natural Selection
Chapter 11

2. What is evolution?
What is biological evolution?

3. What does that mean?
Genetic makeup =
Genetic change =

4. What causes changes in allele frequencies in a population
What causes changes in allele frequencies in a population? (Mechanisms of evolution)
Mutation
Natural selection
Artificial selection
Sexual selection

5. Mutation

6. Natural selection
Three conditions are necessary for this to occur

7. 1. Variation for a trait

8. Variation for a behavioral trait

9. 2. Heritability

10. 3. Unequal reproductive success

11. Measuring reproductive success
Fitness is a measure of

12. Natural selection, cont.

13. Natural selection, cont.
Leads to evolutionary adaptation

14. Natural selection is NOT. . .
. . . a choice. Organisms do not evolve because they want to or “need” to.

15. Remember what we’re talking about? Mechanisms of evolution:
Mutation
Natural selection
Artificial selection
Sexual selection

16. Artificial selection

17. Sexual selection
Same conditions apply. . . results:

18. Sexual selection continued
Leads to sexual dimorphism

19. Remember what a theory is?

20. Evidence of evolution Geology Fossil record Biogeography
Comparative anatomy & embryology
Molecular biology
Laboratory & field experiments

21. Comparative anatomy
Anatomical similarities between species give signs of common ancestry
Homologous structures:
Vestigial organs:

22. Molecular biology