Understanding Evolution of Populations: Key Concepts and Mechanisms

1. Directions: • Title pg. 97 “Evolution of Populations” • Divide your page 97 into 10 different boxes. • Number the boxes 1-10

2. Evolution of Populations

3. #1 Population- group of organisms of the same species that interbreed

4. #2 Gene Pool- all the genes (alleles) present within a population

5. Important! #3 • Natural selection works on the phenotype, not the genotype!

6. #4 Allele Frequency (Relative)- the number of times an allele will appear in a gene pool R R R r r r Total- 6 R- 3  50% r- 3  50%

7. #4 What are the allele frequencies? R- 48 r- 52 “R” has an allele frequency of 48% “r” has an allele frequency of 52%

8. #5 What can introduce variation into a population? Mutation Gene Shuffling from Independent Assortment

9. #6 Genetic Variation is important! Why?! -enables greater survival in a changing environment

10. #7 Genetic Equilibrium- -When allele frequencies remain the same. -No change, no evolution

11. Genetic Equilibrium Requirements #8 1)Random mating 2) Large population 3) No immigration or emigration 4)No mutations 5) No natural selection

12. #9 Genetic Drift- Random change in allele frequency due to small populations No benefit nor harm

13. #10 How does Genetic Drift occur? Bottleneck Effect: only a few survivors from an original population contribute their alleles

14. #10 2) Founder Effect: A subgroup of the population immigrates to and colonizes a new area, changing allele frequencies.

15. Types of Evolution: Adaptive Radiation One species can evolve into many diverse forms