Additional evidence has accumulated over the past 20 years regarding the significance of
the anuran mating call and regarding reinforcement of this premating isolating mechanism�…

The rate at which speciation occurs varies greatly among different kinds of organisms and is
frequently assumed to result from species-or clade-specific factors that influence the rate at�…

In a genetic study of postzygotic reproductive isolation among species of the Drosophila
virilis group, we find that the X chromosome has the largest effect on male and female hybrid�…

We present a new simple model for the evolution of premating reproductive isolation. Using
this model we first analyze the level of genetic variability maintained by mutation in a large�…

I present patterns characterizing the evolution of intrinsic postzygotic isolation in Lepidoptera
by analyzing data from the literature on genetic distance, strength of hybrid sterility and�…

MATERIALS AND METHODS Rana pipiens from the following localities have been used in
hybridization experiments: Alburg, Vermont; Oshkosh, Wisconsin; Mt. Ephraim, New Jersey;�…

The chromosomal determination of interspecific differences in mating behavior was studied
in the interfertile pair, Drosophila arizonensis and Drosophila mojavensis, by means of�…

Yet Rosenhoft's work, which was based entirely on the common European frog, Rana
esculenta, is now known to describe only one of many life-history strategies exhibited by�…

TWENTY-FIVE different crosses, involving 8 species, were attempted. The results fall into 3
groups:(a) in 8 crosses no development occurred;(b) in other 9 it was normal to�…

Sex‐biased dispersal is an important but unexplored area of amphibian ecology. We
predicted female‐biased dispersal in the bullfrog (Rana catesbeiana) based on aspects of�…