Two Species of Tree Frogs That Live Sympatrically in the Northeastern

Multiple Choice

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 difference most likely evolved first?

A) polyploidy
B) difference in mating calls
C) habitat differentiation
D) Polyploidy and different mating calls must have evolved at the same time.