Question

The effective population size of a sexually reproducing, diploid, animal species will be highest when the sex ratio (number of reproducing males / number of reproducing females) is

• A. 1
• B. 0.5
• C. 1.5
• D. 2

Hint:

To maximize genetic diversity and effective population size, the sex ratio should ideally be 1:1.

Answer 1

The Correct Option is A

In population genetics, the effective population size depends on the ratio of males to females. The most balanced and genetically diverse population occurs when the sex ratio is 1:1.

Step 1: Analyzing the options.
- (A) 1: A 1:1 sex ratio is ideal because it ensures that both males and females contribute equally to the next generation, maximizing genetic diversity. - (B) 0.5: A skewed sex ratio with more females than males reduces the number of potential matings and thus decreases genetic diversity. - (C) 1.5: A slightly skewed ratio still does not maximize effective population size as efficiently as a 1:1 ratio. - (D) 2: A 2:1 ratio where there are more males than females is also suboptimal as it reduces the number of female contributions to the gene pool.

Step 2: Conclusion.
The correct answer is (A), as the ideal sex ratio for the highest effective population size is 1:1.

Final Answer: (A) 1