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If extrinsic mortality is high, which of the following statements are correct?

1) Selection will act more strongly against mutations that negatively affect organisms late in life than early in life
2) Selection will act equally strongly on mutations that negatively affect organisms early in life and late in life
3) Organisms should age more rapidly than if extrinsic mortality was low
4) a and c are correct
5) b and c are correct

1 Answer

4 votes

Final answer:

The correct answer in a population facing high extrinsic mortality is that selection will act more strongly on negative mutations affecting early life and organisms should age more rapidly, making option 5 (b and c are correct) the accurate statement.

Step-by-step explanation:

If extrinsic mortality is high in a population, the correct statements are that selection will act less strongly against mutations that negatively affect organisms late in life, because those individuals are less likely to survive to older ages due to environmental factors such as predation, disease, or accidents. Therefore, statement 1 is incorrect. On the contrary, selection will act more strongly on mutations that negatively affect organisms early in their life when those organisms are more likely to be impacted by such selection pressures.

Statement 2 is incorrect as well; the selection pressure is not equal throughout the lifespan under high extrinsic mortality. Statement 3 is correct because high extrinsic mortality generally leads to organisms evolving life history strategies that favor rapid aging, as reproducing quickly before dying from external factors becomes more advantageous. Hence, option 4 (a and c are correct) is incorrect, and the correct answer is option 5 (b and c are correct).

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