In a hypothetical environment, fishes called pike-cichlids are visual predators of large, adult algae-eating fish (in other words, they locate their prey by sight). The population of algae-eaters experiences predatory pressure from pike-cichlids. Which of the following is least likely to result in the algae-eater population in future generations?
A) selection for drab colouration of the algae-eaters
B) selection for nocturnal algae-eaters (active only at night)
C) selection for larger female algae-eaters, bearing broods composed of more, and larger, young
D) selection for algae-eaters that become sexually mature at smaller overall body sizes

Question

Quizplus · Accepted Answer

Selection for larger female algae-eaters, bearing broods composed of more, and larger, young is the least likely to result in the algae-eater population in future generations because it would lead to an increase in the overall size and abundance of the species, thereby increasing the likelihood of predation by pike-cichlids. Selection for drab colouration and nocturnal activity would reduce the algae-eaters' visibility to pike-cichlids, reducing the predation pressure. Selection for smaller body sizes at sexual maturity would allow the algae-eaters to reproduce at a younger age and potentially reduce their exposure to predation over their lifetime.

In a Hypothetical Environment, Fishes Called Pike-Cichlids Are Visual Predators