Question

What is the significance of genetic drift and gene flow?

Answer 1

Genetic drift: Random changes in genetic variation from generation to generation due to chance
There are two version : Founder Effect and Bottleneck Effect
Gene Flow: Migration occurring between two different interbreeding populations with different allele frequencies

Explanation:

Genetic drift: Random changes in genetic variation from generation to generation due to chance
There are two version : Founder Effect and Bottleneck Effect

1. Founder Effect: Small section of population breaks off to start a new population
   Eg: A group of foxes run away from a bigger population of foxes (mother population) and start a new colony (allele frequency is based on chance)

2. A major event which kills off a majority of the starting population
   Eg: There is a forest fire that kills a very big majority (let's say 90%) of the population, the gene pool (allele frequency) of the new population is based on chance.

Gene Flow: Migration occurring between two different interbreeding populations with different allele frequencies
Eg: Canadian and Russian geese come together during migration and have babies (they are transferring their gene pools)