Three-spined stickleback fish (Gasterosteus aculeatus) show substantial genetic variation in gill-raker length related to differences in their diets. Longer gill rakers appear to function better for capturing open-water prey, while shorter gill rakers function better for capturing shallow-water prey. Which of the following types of selection is most likely to be found in a large lake (open water in the middle and shallow water around the sides) with a high density of these fish?
A) directional selection
B) stabilizing selection
C) disruptive selection
D) sexual selection

Question

Quizplus · Accepted Answer

Disruptive selection is most likely because it favors individuals at both extremes of a trait distribution, in this case, fish with either long or short gill rakers, due to the different feeding advantages in open water versus shallow water.

Three-Spined Stickleback Fish (Gasterosteus Aculeatus) Show Substantial Genetic Variation in Gill-Raker