Two species of tree frogs that live sympatrically in the northeastern United States differ in ploidy: Hyla chrysoscelis is diploid, and Hyla versicolor is tetraploid. The frogs are identical in appearance, but their mating calls, which females use to find mates, differ. Which likely evolved first?
A) Polyploidy
B) Reproductive isolation
C) Behavioral isolation
D) All of the above evolved at the same time.

Question

Quizplus · Accepted Answer

Polyploidy likely evolved first, as it leads to a change in the number of chromosome sets in a species, creating reproductive isolation between individuals with different ploidy levels. This can lead to rapid speciation. Reproductive and behavioral isolation may then evolve over time, as a result of the polyploidy-induced genetic changes.

Two Species of Tree Frogs That Live Sympatrically in the Northeastern