Question

Northern elephant seals were hunted to the point that their population size was reduced to as few as 20 in the late 1800s. Since then, their populations have rebounded to over 30,000. However, the genetic diversity is significantly reduced in the rebounded population of elephant seals. What explains this lack of genetic diversity in a population of 30,000? A) Natural selection reduced genetic diversity as those that survived had the most favorable traits. B) Artificial selection reduced genetic diversity, as humans chose the preferred phenotypes of the elephant seals that survived in the 1800s. C) Population bottleneck reduced genetic diversity, as the gene pool of the 30,000 elephant seals resulted from the few alleles present in the 20 bottleneck survivors. D) Gene flow decreased genetic diversity, as significant numbers of elephant seals migrated to remote locations far from humans, leaving only a limited genetic diversity.

Answer 1

Answer:

C) Population bottleneck reduced genetic diversity, as the gene pool of the 30,000 elephant seals resulted from the few alleles present in the 20 bottleneck survivors.

Explanation:

The correct answer would be that population bottleneck reduced genetic diversity, as the gene pool of the 30,000 elephant seals resulted from the few alleles present in the 20 bottleneck survivors.

A sudden decrease in the population of an organism as a result of disaster or any other factor leads to a population bottleneck - a decrease in the genetic variability of the population.

The decrease in the available number of alleles in the population limits the amount of genes that natural selection can influence.  Hence, as the population keeps increasing, the genetic diversity of the entire population rarely changes because the few alleles present in the population keep recombining.

The correct option is C.