Assortative mating and the cost of inbreeding - A simulation approach

Assortative mating is an important factor in the process of speciation. Models of speciation frequently deal with small founder populations often with mating preferences based on ecological traits or habitat preferences. Small populations, on the other hand might suffer from inbreeding. However, few studies have explored the combined effects of assortative mating and inbreeding in such populations. Can they speciate, or are they doomed to eventually go extinct? With this simulation we show that assortative mating based on similarities increases the possibility for change in a population, as long as the population does not suffer from inbreeding depression. Inbred populations seem not to be able to cope with strong assortative mating, as this is likely to elevate the level of inbreeding, increasing the risks of inbreeding depression and as a result decreasing population mean fitness. This in turn hinders the possibility of change, and instead might drive the population to extinction. (C) 2012 Elsevier B.V. All rights reserved.