Genetic tradeoff as a model for parapatric speciation

This paper uses an individual-based modelling approach to explore the effects of genetic tradeoff across a spatial gradient. Tradeoff is represented by the ability of an individual to live at higher environmental values - individuals that can live at high values can also live at low values, but the cost for this generalised ability is an increased time to breeding maturity. This paper shows that for very low tradeoff gradients significant zones still occur across the environment, with a pronounced set of heterozygotic bands. It is proposed that these bands represent hybrid zones, and that the model demonstrates that weak tradeoff across an environmental gradient can produce isolated genetic individuals. This model therefore shows one mechanism leading to parapatric speciation.PublishedNon Peer ReviewedBall, M. C. (1988). “Ecophysiology of mangroves” Trees. 2: 129–142. Czesak,M. E. & Fox, C. (2002). “Evolutionary ecology of egg size and number in a seed beatle: Genetic trade-off differs between environments.” Evolution. 57(5): 1121–1132. Endler, J. A. (1977). Geographic variation, speciation and the origin of species.. Columbia Univ,Press, Princtton, NJ. Leroi, A. M., Chippindale, A. K. & Rose, M. R. (1994). “The role of genotype-by-environmental interaction.” Evolution. 48(4): 1244–1258. Luckinbill, L. S., Arking, M. J., Clare,M. J., Cirocco,W. C. & Buck, S. (1984). “Selection for delayed senescence in Drosophila melanogaster.” Evolution. 38: 996–1003. Rose, M. R., Corey, M. L., Coyle, A. M. & Service, P. M. (1984). “The morphology of postponed senescence in Drosophila melanogaster.” Canadian Journal of Zoology. 62: 1576–1580. S.Gavrilets, Li, H. & Vose, M. D. (2000). “Patterns of parapatric speciation.” Evolution. 54(4): 1126–1134. von Neumann, J. (1966). Theory of self-reproducing automata.. University of Illinois Press.. W, R. R. & E, E, H. (1993). “Laboratory experiments on speciation: What have we learned in 40 years?” Evolution. 47: 1637–1653