Question

question 17 (5.555555556 points)
a small island population of birds becomes isolated from the mainland. how might this isolation affect both the genetic diversity and ecological role of this population?
the population would quickly develop identical traits to the original mainland population
both genetic diversity and ecological adaptations would remain unchanged over time
genetic diversity decreases; ecological role becomes more specialized to island conditions
genetic diversity would increase due to reduced competition from mainland populations

Explanation:

1. Analyze Option 1: Isolation prevents gene flow, so traits won't quickly match the mainland. Eliminate.
2. Analyze Option 2: Evolution and adaptation occur over time, so both can't remain unchanged. Eliminate.
3. Analyze Option 3: Small isolated populations have reduced genetic diversity (founder effect, genetic drift). Island conditions select for specialized ecological roles (e.g., new food sources, niches). This matches.
4. Analyze Option 4: Reduced competition doesn't increase genetic diversity; isolation and small population size typically decrease it. Eliminate.

Answer:

C. Genetic diversity decreases; ecological role becomes more specialized to island conditions