Read each example and decide what the resulting effect on the gene pool of that population would be.

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.

A zebra migrates to join a different herd of zebras.

    This would lead to biodiversity in the new zebra herd.

Competition for sunlight leads to taller trees.

    Taller trees would prosper, and shorter trees would die out. Trees would continuously evolve to be larger.

The DNA of a snake changes to make its venom stronger.

    This mutation created biodiversity and favoritism in natural selection. The trait will more likely be passed on.

A grassfire randomly sweeps through a population of buffalo and kills most of the animals.

    Only the strongest Buffalo survived, decreasing competition strengthening the gene pool.

Genetic variation as it is an important factor causes evolution by increasing or decreasing the frequency of alleles in a particular population through the process of natural selection.

On the basis of knowledge about genetic variation, we can conclude that-

1st example -  Increase in gene pool of zebra.

2nd example - Decrease in gene pool of trees.

3rd example - Increase  the gene pool of snakes.

4th example - Decrease  of gene pool of buffalo.

yes it is weird but true