An example of a gene pool would be:

In ecology, gene pool can be described as a combination of different genes present in a population. A population having reduced variability in its gene pool will cause reduced fitness. A population rich in gene pool will have enhanced fitness. A gene pool represents all the alleles of every gene whether those which are functioning or those which are recessive.

An example of a gene pool is a population of birds, a population of butterflies, a population of humans etc.