Question

a population of birds lives on a small island. another population of the same species lives on the mainland. the distance between the island and the mainland is too great for birds to fly back and forth. recently, a series of sandbars and tiny islands have formed between the island and the mainland.
what is the most likely effect of this?
o an increase in mutations in both bird populations
o an increase in gene flow between the bird populations
o an increase in genetic drift between the bird populations
o an increase in mutations in the island population

Explanation:

Gene flow is the transfer of genetic material from one population to another. Previously, the distance was too great for birds to fly back and forth, limiting gene flow. Now, with sandbars and tiny islands formed, it's easier for birds to move between the island and mainland populations, thus increasing gene flow. Mutations are random changes in DNA and not directly caused by the formation of sandbars. Genetic drift is a change in allele frequencies due to chance events, which isn't indicated here.

Answer:

an increase in gene flow between the bird populations