Evolution of Populations AP Biology Title Types of

Evolution of Populations AP Biology

Title: Types of Evolutionary Change Mutat ion AP Biology Genetic Drift Select ion Gene Flow Non-random mating

1. Mutation & Variation ► Mutation creates variation ► Mutation changes DNA sequence, changes amino acid sequence, and changes proteins. AP Biology

2. Gene Flow ► Movement of individuals and their alleles in & out of populations ► Causes genetic mixing across regions ► seed & pollen distribution by wind & insect ► migration of animals ► sub-populations may have different allele frequencies ► reduce differences between populations AP Biology

3. Non-random mating ► Sexual selection ► Organisms may prefer to mate with others of the same genotype or of different genotypes. AP Biology

4. Genetic drift ► 2 types: ► founder effect ► small ► group splinters off & starts a new colony bottleneck ► some factor (disaster) reduces population to small number & then population recovers & expands again AP Biology nd ou es Gr nch fi fin Tree ch es er Warbl finch

4. Genetic drift ► Founder Effect- When a new population is started by only a few individuals. ► some rare alleles may be at high frequency; others may be missing ► skew the gene pool of new population ► human populations that started from small group of colonists ► example: colonization of New World AP Biology

Bajau People ► https: //www. youtube. com/watch? v=T 3 f. Of 5 YZI-Q AP Biology

4. Genetic drift ► Bottleneck Effect- When large population is drastically reduced by a disaster and lowers variation. Also narrows the gene pool. ► famine, natural disaster, loss of habitat… ► loss of variation by chance event ► alleles lost from gene pool ► AP Biology not due to fitness

5. Natural selection ► Survival & reproduction due to changing environmental conditions. ► ► climate change ► food source availability ► predators, parasites, diseases ► toxins combinations of alleles that provide “fitness” increase in the population ► AP Biology adaptive evolutionary change

5 Agents of evolutionary change Mutation Gene Flow Genetic Drift AP Biology Non-random mating Selection