Generally speaking, there are numerous issues related to genetic diversity which include mutations, sexual reproduction, migration, and population size.
To begin with, mutations (any change in the DNA sequence of an organism) introduce new genetic information into a population by altering alleles (a form of a gene usually arising through mutation) that are already present. Occasionally, a mutation introduces a new allele into the gene pool of species. On the other hand, a mutation may introduce an allele that was deficient in a local population. Meanwhile, it is present in other populations of species. All the different …show more content…
Often, when genetic diversity is reduced, deleterious recessive alleles in closely related mates are passed to offspring in a homozygous state, resulting in offspring that have reduced chances of survival. Most zoo managers have recognized the importance of increasing genetic diversity in their small populations of animals and have instituted programs of loaning breeding animals to distant zoos in an effort to increase genetic diversity. In effect, they are attempting to simulate the natural migration that frequently introduces new alleles from distant populations.
Furthermore, the size of the population has much to do with how effective any mechanism is at generating diversity within a gene pool, any mechanism is at generating diversity within a gene pool. The smaller the population, the less genetic diversity it can contain. Therefore, migrations, mutations, and accidental death can have great effects on the genetic makeup of small population. For example, if a town has a population of twenty people and only two have brown eyes and the rest have blue eyes, what happens to those two brown eyes people is more critical than if the town has 20,000 people and 2,000 have brown eyes. Although the ratio of brown eyes to blue eyes is the same in both cases, even a small change in a population of twenty could significantly change the frequency of the brown-eye allele.