Question

After controlling for the effect of relatedness among species of bats, what was the conclusion with regard to testes size in bats?

1) testes size is not really related to body size
2) larger bats had smaller testes
3) larger bats had larger testes size
4) testes size is related to social group size

Answer 1

The correct option is 4. Testes size in bats is related to social group size, rather than body size, with larger social groups leading to larger testes due to increased sperm competition.

Step-by-step explanation:

After controlling for the effect of relatedness among species of bats, studies have found that testes size is related to social group size rather than to body size. Contrary to what one might expect, there isn't a straightforward relationship between body size and testes size, as larger bats do not necessarily have larger testes.

Instead, evolutionary adaptations in bats indicate a correlation between testes size and social structures, with social group size playing a significant role in determining testes size. This is because sperm competition is often more intense in species where males have more rivals for mating, which can occur in larger social groups. Hence, the correct option is (4) testes size is related to social group size.