School of Biological Sciences A12, Sydney University, N.S.W. 2006, Australia and Institute of Ecology and Genetics, University of Aarhus, Denmark.
Genetics. 1981 Jan;97(1):217-35. doi: 10.1093/genetics/97.1.217.
A Monte-Carlo simulation program is described for a polygenic mating model introduced in the first paper in this series (Sved 1981). The program is used to simulate the situation in laboratory experiments in which two strains are allowed to mass-mate, hybrids are artificially eliminated and the establishment of mating isolation is studied. It is shown that, if mating choice is sufficiently precise, a combination of chance fluctuation and selection can lead to divergence in mating behavior. However, for small population sizes, the variability would usually be considerably reduced by the time some divergence is established, leading to low eventual levels of isolation. For larger population sizes, on the other hand, it may take many generations for any divergence to be established.-A dissection of the selective forces involved in the divergence shows that the major force potentially responsible for initial selective response is the tendency for divergent females and males to reject mates from the wrong strain. However, this is nullified in mixed-strain matings by the tendency of such individuals equally to reject mates from the correct strain. To overcome this problem, it is suggested that the usual mixed-strain mating procedure be replaced by procedures specifically designed to select for rejection of interstrain matings. Two procedures are suggested for this, and computer simulation shows that one or other of the procedures will work under the assumptions of the mating model. Other possible outcomes of selection, including asymmetrical divergence, are discussed for cases in which the assumptions of the mating model are invalid.
描述了一个用于多基因交配模型的蒙特卡罗模拟程序，该模型在本系列的第一篇论文（Sved 1981）中引入。该程序用于模拟实验室实验中的情况，在这种情况下，允许两个品系大量交配，人工消除杂种，并研究交配隔离的建立。结果表明，如果交配选择足够精确，机会波动和选择的组合可以导致交配行为的分歧。然而，对于小种群大小，在建立一些分歧时，可变性通常会大大降低，导致最终隔离水平较低。另一方面，对于较大的种群大小，可能需要许多代才能建立任何分歧。-对分歧中涉及的选择力进行剖析表明，导致分歧的雌性和雄性排斥来自错误品系的配偶的倾向是潜在的主要选择力。然而，在混合品系交配中，这些个体同样排斥来自正确品系的配偶的倾向使这种情况无效。为了解决这个问题，建议用专门设计的程序来选择排斥种间交配的程序取代通常的混合品系交配程序。为此提出了两种程序，计算机模拟表明，在交配模型的假设下，这两种程序中的一种或另一种程序将起作用。对于交配模型的假设无效的情况，讨论了包括不对称分歧在内的其他选择结果。
