Researchers have been studying a rare population of 87 voles in an isolated area. ten voles from a larger population were added to this isolated population.
besides having 10 additional animals, what benefits are there to importing individuals?

Addition of voles from a larger population will help increase the genetic diversity and combat inbreeding depression.

The voles of the rare population did not have much genetic diversity. Addition of voles from the larger population will allow the rare voles to breed with the ten voles from the larger population. As a result, genetic diversity will be produced.

Inbreeding depression refers to a decreased fitness level in species due to inbreeding. Addition of the ten voles from a larger population will allow more choices for breeding.

the answer for this question would be d. glaciers

that is wrong, its not thymus.