York Centre for Complex Systems Analysis, Department of Biology and Department of Computer Science, University of York, York, United Kingdom.
Evolution. 2009 Oct;63(10):2697-706. doi: 10.1111/j.1558-5646.2009.00748.x. Epub 2009 Jun 10.
Visible genetic polymorphism is a common feature of many species. In most cases, the mechanism(s) underlying the maintenance of such variation remain obscure although apostatic selection has often been suggested. Here, we explore individual-based evolutionary models to understand what features of predator-prey relationships may lead to patterns of exuberant polymorphism similar to those observed in the wild. When all morphs are equally visible, the number of evolved morphs increases with the strength of apostatic selection although even with powerful selection the number morphs is still relatively small. The introduction of dietary wariness increases the number of morphs substantially, even when apostatic selection is absent. When one morph is more cryptic the number of evolved morphs is fewer. The cryptic morph reaches high frequency in the population and other morphs are each at lower frequencies. Decreasing the predation intensity enhances the number of evolved morphs in all models. Dietary wariness is a critical factor missing from earlier models and it may provide a general solution to the problem of polymorphisms involving many morphs. Apostatic selection is shown to be neither a necessary, nor a sufficient, requirement for the maintenance of exuberant polymorphisms.
可见的遗传多态性是许多物种的共同特征。尽管经常有人提出突变异选择，但大多数情况下，维持这种变异的机制仍不清楚。在这里，我们探索基于个体的进化模型，以了解捕食者-猎物关系的哪些特征可能导致与野外观察到的相似的过度多态现象。当所有形态都同样可见时，随着突变异选择的强度增加，进化出的形态数量增加，尽管即使选择非常强大，形态的数量仍然相对较少。引入饮食谨慎性会大大增加形态的数量，即使突变异选择不存在也是如此。当一种形态更隐蔽时，进化出的形态数量就会减少。隐蔽形态在种群中达到高频率，而其他形态的频率则较低。降低捕食强度会增加所有模型中进化出的形态数量。饮食谨慎性是早期模型中缺失的一个关键因素，它可能为涉及多种形态的多态性问题提供一个普遍的解决方案。突变异选择既不是维持过度多态性的必要条件，也不是充分条件。
