You are studying a potential case of incipient sympatric speciation involving two morphs of a cichlid fish in a crater lake that feed at different depths and differ in morphology. If true, which of the following statements would make sympatric speciation more likely (or at least possible)? i. The two morphs specialize on different food types; matings between the morphs produce offspring that are intermediate and can efficiently utilize both food types.
Ii) The two morphs feed on different food types, and there is strong disruptive selection operating such that individuals that are intermediate are very strongly selected against (basically none survive).
Iii) Mating occurs in the area of the lake where each morph feeds. Also, females choose males based on jaw morphology, preferring males that have the same jaw morphology as the female.
Iv) The two morphs feed at different depths, but both morphs come to a rocky area near the shore to mate. Females prefer to mate with males of the other morph.

Question

Quizplus · Accepted Answer

Sympatric speciation is more likely when there is disruptive selection against intermediates (ii) and when mating is non-random, with preferences for similar traits (iii), both of which promote reproductive isolation within the same geographic area.

You Are Studying a Potential Case of Incipient Sympatric Speciation