Question

identifying the change in genetic variation from the mechanisms that influence gene pools
read each example and decide whether each would increase or decrease the genetic variation in the gene pool of that population.
a zebra migrates to join a different herd of zebras.
competition for sunlight leads to taller trees.
the dna of a snake changes to make its venom stronger.
a grassfire randomly sweeps through a population of buffalo and kills most of the animals.

Explanation:

• When a zebra migrates to join a different herd, it brings in new genetic material from its original herd, thus increasing genetic variation.
• Competition for sunlight leading to taller trees is a form of natural selection. It favors a particular trait (tallness) and reduces the genetic variation as non - tall tree variants are less likely to survive and reproduce.
• A change in the DNA of a snake (mutation) creates a new allele (for stronger venom), which increases genetic variation.
• A grassfire randomly killing most of the buffalo population is a genetic drift event (bottleneck effect). It reduces the number of individuals in the population, and thus the genetic variation as many alleles may be lost.

Answer:

• A zebra migrates to join a different herd of zebras: Increase.
• Competition for sunlight leads to taller trees: Decrease.
• The DNA of a snake changes to make its venom stronger: Increase.
• A grassfire randomly sweeps through a population of buffalo and kills most of the animals: Decrease.