Neuroanatomy influences speciation rates among anurans.

Evolutionary divergence among animal courtship signals is an important component of the speciation process. In anurans, the preferential response of females to the mating call of conspecific males often maintains reproductive isolation among populations. Much of the information in the call is initially processed in the inner ear, and there is considerable variation in the structure of this organ among lineages of frogs. This variation is responsible for differences in the frequency range to which frog species are sensitive and thus influences the frequency range over which mating calls can effectively diverge. Data suggest that this influence of neuroanatomy on mating call divergence is partly responsible for the different rates of speciation among lineages of frogs.