Apopulation has a small size, high level of genetic drift, and very little migration into the population. what will most likely happen to the genetic diversity in the population over time? a. genetic diversity will increase because the existing alleles will mutate into new alleles. b. genetic diversity will remain unchanged because genetic drift does not have much of an impact on small populations. c. genetic diversity will remain unchanged because high levels of genetic drift offset low levels of gene flow. d. genetic diversity will decrease because existing alleles will be lost and few new alleles will be introduced.

D. Genetic diversity will decrease because existing alleles will be lost and few new alleles will be introduced.

Explanation:

Genetic drift is a very important factor that brings changes in gene pools over a period of time. Although genetic drift can happen in the population of any type or size but its effects are more evident in small populations.

So as mentioned in question that three conditions: population has a small size, high level of genetic drift, and very little migration into the population.

It means that in small population where genetic drift is high,alleles are either lost by a population or there will be only few alleles present at specific gene loci of population. This will cause decrease in genetic diversity specifically because of small size of population.

What happens that genetic drift causes random sampling in population like some reproduce while others not, for example see the population of butterflies in image. Genetic drift caused only blue ones to multiply and reproduce while others just could not reproduce, This lead to a population 2 with low genetic diversity that is quite evident.

Hope it help!