Question

why are small, isolated populations (such as those on small islands) at greater risk of extinction?

○ they always have more predators than mainland populations.

○ their limited genetic diversity makes them vulnerable to disease and environmental changes.

○ they reproduce so quickly that resources are never sufficient.

○ they can always migrate away if conditions worsen.

Explanation:

• Option 1: Small island populations don't necessarily have more predators; this is incorrect.
• Option 2: Small, isolated populations have limited genetic diversity. Lower genetic diversity means fewer traits to adapt to diseases or environmental changes, increasing extinction risk. This makes sense.
• Option 3: Small populations typically have slower reproduction (due to limited numbers), and resource insufficiency isn't a defining reason for their extinction risk compared to genetic diversity issues.
• Option 4: Isolated populations (like on small islands) can't easily migrate away, so this is incorrect.

Answer:

B. Their limited genetic diversity makes them vulnerable to disease and environmental changes.