Suppose that a large river separates two populations of mice. one population is all black, and the other all white. a beaver dam that is built allows the mice to cross the river. over time, many gray mice are born. what is this an example of?

Thank you for posting your question here at brainly. I hope the answer will help you. Feel free to ask more questions.
The gray mice would be an indication that the genetic traits for black fur and white fur in these mice are codominant. If you define black mice as BB and white mice as WW, when they breed together they produce gray mice, BW.

Answer Link

Erudite1 Erudite1 · Answer 2 · 2018-07-18T10:18:48+02:00

This is an example of CONDOMINANCY.

Condominancy is said to occur when two different alleles are combined together to form a different allele, in which the alleles are expressed equally and none of them is dominant. In the example given above, the black rat population mated with the white rat population to produce offspring that are grey in colour. Thus, the white and the black colour of the parents are not dominant, but are equally expressed to give gray colour.