1. Individuals in a population may evolve. A.True B.False False! Individuals do NOT evolve; POPULATIONS do!

2. Individuals do NOT evolve! Individuals survive or don’t… Individuals reproduce or don’t… Individuals are selected… Populations evolve!

3. Evolution of Populations Populations evolve when they undergo genetic change.

4. What causes populations to undergo genetic change & evolve? Natural selection is NOT always the cause of evolution! There are 5 things that could cause a genetic change in a population: – Mutation – Gene Flow – Non-random Mating – Natural Selection – Genetic Drift

5. 5 Agents of Evolutionary Change

6. 1. Mutation & Variation Mutations create variation & new mutations appear randomly. Mutations change the DNA sequence. – Changes in the protein may change the phenotype & therefore change the fitness! All blue (B) B occurs 100% of the time. Some blue (B), some red (b) Genetic change = evolution!

7. 2. Gene Flow Movement of individuals & their alleles in/out of populations – Seed & pollen distribution by wind & insects – Migration of animals

8. Human Evolution Today Gene flow in human populations is increasing. – Transferring alleles between populations Are we moving towards a blended world?

9. 3. Non-Random Mating Sexual selection occurs when certain traits increase mating success. What will happen to the population over time if the tan beetles do not reproduce?

10. 4. Genetic Drift Change in allele frequencies due to chance – Bottleneck Effect – Founder Effect

11. 5. Natural Selection Differential survival & reproduction due to selective pressures – Climate change, food source availability, predators, etc. Combinations of alleles that increase fitness will become more common in the population!