Question

in coho salmon, hooknose males are large and jack males are small. average - sized males exist but are rare. which statement best explains disruptive selection in male coho salmon?
average - sized males reach the spawning ground first.
the scent of average - sized males makes them most attractive to females.
the relative size of hooknose males and jack males is an advantage over average - sized males during mating.
hooknose males produces stronger sperm than jack males or average - sized males.

Explanation:

Disruptive selection favors extreme phenotypes over intermediate ones. In coho salmon, hooknose (large) and jack (small) males having an advantage over average - sized males during mating (which is a reproductive advantage) aligns with the concept of disruptive selection. The other options either suggest an advantage for the intermediate (average - sized) phenotype (options 1 and 2) or a comparison between the extreme phenotypes (option 4) which is not relevant to disruptive selection's focus on extremes vs intermediate.

Answer:

The relative size of hooknose males and jack males is an advantage over average - sized males during mating.