Answer: The correct answer for the given mechanisms influencing gene pool are the mechanisms of evolutionary change, which are described as follows-
1) Gene Flow
- It is described as the transfer of genes from one population to another population so that frequency of gene is increased.
-A zebra migrates to join a different herd of zebras.
2) Natural Selection
- A mechanism of evolutionary change in which individuals with advantageous traits survive and reproduce whereas the others ( those that can not adapt) eliminate from the population.
-Competition for sunlight leads to taller trees.
3) Mutation
- Permanent change in the nucleotide sequence of DNA ( genetic material) that could have harmful or useful consequences.
-The DNA of a snake changes to make its venom stronger.
4) Genetic Drift - It is a random phenomenon ( that occurs by chance such as fire) that results in change in the gene frequency in a small population.
-A grassfire randomly sweeps through a population of buffalo and kills most of the animals.