Beltman J B, Metz J A J
Section Theoretical Biology, Institute of Biology, Leiden University, The Netherlands.
Proc Biol Sci. 2005 Jul 22;272(1571):1455-63. doi: 10.1098/rspb.2005.3104.
A problem in understanding sympatric speciation is establishing how reproductive isolation can arise when there is disruptive selection on an ecological trait. One of the solutions that has been proposed is that a habitat preference evolves, and that mates are chosen within the preferred habitat. We present a model where the habitat preference can evolve either by means of a genetic mechanism or by means of learning. Employing an adaptive-dynamical analysis, we show that evolution proceeds either to a single population of specialists with a genetic preference for their optimal habitat, or to a population of generalists without a habitat preference. The generalist population subsequently experiences disruptive selection. Learning promotes speciation because it increases the intensity of disruptive selection. An individual-based version of the model shows that, when loci are completely unlinked and learning confers little cost, the presence of disruptive selection most probably leads to speciation via the simultaneous evolution of a learned habitat preference. For high costs of learning, speciation is most likely to occur via the evolution of a genetic habitat preference. However, the latter only happens when the effect of mutations is large, or when there is linkage between genes coding for the different traits.
理解同域物种形成的一个问题是，当对某一生态性状存在分裂选择时，如何产生生殖隔离。已提出的一种解决方案是，栖息地偏好会进化，且在偏好的栖息地内选择配偶。我们提出一个模型，其中栖息地偏好可以通过遗传机制或学习方式进化。通过适应性动力学分析，我们表明进化要么朝着对其最优栖息地具有遗传偏好的单一专家种群发展，要么朝着没有栖息地偏好的通才种群发展。通才种群随后会经历分裂选择。学习促进物种形成，因为它会增加分裂选择的强度。该模型基于个体的版本表明，当基因座完全不连锁且学习成本很低时，分裂选择的存在很可能通过习得的栖息地偏好的同时进化导致物种形成。对于高学习成本，物种形成最有可能通过遗传栖息地偏好的进化发生。然而，后者仅在突变效应较大时，或在编码不同性状的基因之间存在连锁时才会发生。
