DISRUPTIVE SELECTION ON HABITAT PREFERENCE AND THE EVOLUTION OF REPRODUCTIVE ISOLATION: A SIMULATION STUDY.

Abstract

There has been a wide diversity of theoretical work on the genetic mechanisms that promote speciation under sympatric (non-allopatric) conditions (see Thoday and Gibson, 1970; Bush, 1975; Endler, 1977; White, 1978; Futuyma and Mayer, 1980; Templeton, 1981 for review). The conclusion from this work is that sympatric speciation is genetically possible but it is not clear whether or not it has played a major role in the generation of species under natural conditions. Assessing the evolutionary importance of sympatric speciation awaits the identification of those environmental circumstances that are most likely to promote the process. Here I suggest that environmental conditions which produce disruptive selection on habitat preference represent a special case in which sympatric speciation is particularly likely to occur. By habitat preference I mean any tendency of an organism to become non-randomly associated with a particular spatial and/ or temporal part of an environment.