Which of the following best explains why organisms of the same species that become isolated eventually become different from each other over time

They are exposed to different environments

When animals are isolated from each other and put in different environments, they react to their environment differently and this causes them to adapt differently.  

i'm gonna put a couple so you can chose from

explanation:

if you know the fur color of the offspring mice, you can use the ratios to identify the genotypes of the parents.

if either parent mouse passes a dominant allele, the offspring will have black fur.

if the parental mice has two different fur color (i.e white and black) , the color of the offspring's fur would be either black, white, or the combination of both (grey)

hope this : )

the answer is sex-linked recessive.