Question

Female stickleback prefer males with brighter red coloration on their belly. Given the results depicted in the graph below, it appears that females that choose redder males benefit from:

A) sensory bias
B) direct benefits
C) good genes
D) nuptial gifts

Answer 1

Female stickleback fish's preference for males with brighter red coloration is an example of sexual selection, supporting the good genes hypothesis, indicating genetic quality and not related to sensory bias, direct benefits, or nuptial gifts. Option C.

Step-by-step explanation:

The female stickleback fish's preference for males with brighter red coloration on their belly is an example of sexual selection. This preference can be related to the good genes hypothesis, which suggests that such ornamental traits in males (like bright red coloration) may be indicative of genetic quality.

Since these traits can imply a male's efficient metabolism or an ability to fight off diseases, females benefit by choosing these males, potentially obtaining better genes for their offspring. Hence, the brighter coloration would not be because of sensory bias, direct benefits, or nuptial gifts, but rather a signal of genetic superiority.

The observations in John Endler's study of Trinidad guppies provide a similar example. In areas with high predation, male guppies were drab to better camouflage and avoid predators, whereas in areas without predators, the males developed brighter colors, possibly due to female preference, illustrating sexual selection.

This visual display of coloration is not connected to the provision of nuptial gifts, sensory biases, or direct benefits, further reinforcing the role of good genes in mate choice.

SO Option C is correct.