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? an increase in gene flow between the bird populations; an increase in genetic drift between the bird populations; an increase in mutations in both bird populations; an increase in mutations in the island population

Explanation:

1. Analyze the situation: Initially, the distance prevented bird movement between the island and mainland populations. Now, sandbars and tiny islands form a path.
2. Evaluate each option:

• Option 1: Gene flow is the transfer of genetic material between populations. With a path, birds can move, so gene flow between the two populations is likely to increase.
• Option 2: Genetic drift is random change in allele frequencies, usually in small populations. The formation of a path allows gene flow, which reduces the isolation needed for strong genetic drift between the two populations, so this is incorrect.
• Option 3: Mutations are random and not directly caused by the formation of a path between populations, so this is incorrect.
• Option 4: Mutations are not triggered by the presence of a path between populations; they are random, so this is incorrect.

Answer:

an increase in gene flow between the bird populations