The Entomologist's Record and Journal of Variation, Vol. 109

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Excerpt from The Entomologist's Record and Journal of Variation, Vol. 109: January-February, 1997The most commonly used definition of a biological species is based upon effective reproduction. Members of a sexually reproducing species do, or potentially could, inter-breed amongst themselves, but not with members of other species (mayr, This definition implies not only that matings occur, but that viable and fertile offspring are produced. Matings between individuals of putatively different species have long interested biologists for their potential in helping to unravel the evolutionary mechanisms of speciation, the nature of barriers to mating and so gene-¿ow between populations, and their possible role in the origin of new species.Matings between members of different species are a waste of reproductive resources for both partners. The waste for females is generally greater than for males, because females produce large, heavily resourced gametes, while males produce small gametes containing little more than a nucleus and a tail. However, the cost to males is not negligible. Not only does a male that mates with a female of another species waste gametes, he wastes energy in mating, he wastes time that might be used in more productive ways such as feeding, resting or courting more appropriate females, and, as he is less mobile while copulating, he may be more prone to predation. He also runs the risk of contracting disease from his mating partner. Of course females are liable to these latter costs as well.About the PublisherForgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.comThis book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully, any imperfections that remain are intentionally left to preserve the state of such historical works.