Data from: Mating timing, dispersal, and local adaptation in patchy environments

Dispersal is a life-history trait that can evolve under various known selective pressures as identified by a multitude of theoretical and empirical studies. Yet only few of them are considering the succession of mating and dispersal. The sequence of these events influences gene flow and consequently affects the dynamics and evolution of populations. We use individual-based simulations to investigate the evolution of the timing of dispersal and mating, i.e. mating before or after dispersal. We assume a discrete insect meta-population in a heterogeneous environment, where populations may adapt to local conditions and only females are allowed to disperse. We run the model assuming different levels of species habitat tolerance, carrying capacity, and temporal environmental variability. Our results show that in species with narrow habitat tolerance low to moderate dispersal evolves in combination with mating after dispersal (post-dispersal mating). With such a strategy dispersing females benefit from mating with a resident male, as their offspring will be better adapted to the local habitat conditions. On the contrary, in species with wide habitat tolerance higher dispersal rates in combination with pre-dispersal mating evolves. In this case individuals are adapted to the 'average' habitat where pre-dispersal mating conveys the benefit of carrying relatives' genes into a new population. With high dispersal rates and large population size, local adaptation and kin-structure both vanish and the temporal sequence of dispersal and mating may become a (nearly) neutral trait.

扩散（dispersal）是一种生活史性状，可在大量理论与实证研究已证实的多种选择压力下发生演化。然而现有研究中极少同时考量交配与扩散的先后次序，而两类事件的发生顺序会影响基因流，进而作用于种群的动态与演化过程。本研究采用基于个体的模拟（individual-based simulation）方法，探究扩散与交配的时机演化——即交配发生在扩散之前还是之后。我们假设在异质环境中存在离散的昆虫集合种群（meta-population），各种群可适应当地环境，且仅雌性个体具备扩散能力。本模型设置了不同的物种生境耐受性、环境容纳量以及时间尺度环境变异性参数开展模拟。研究结果表明：对于生境耐受性较窄的物种，会演化出低至中等强度的扩散模式，并伴随扩散后交配（post-dispersal mating）策略；采用该策略的扩散雌性个体可通过与本地雄性交配获得收益，因为其后代能更好地适应当地生境条件。与之相反，生境耐受性较宽的物种则会演化出较高的扩散速率，并伴随扩散前交配（pre-dispersal mating）策略；此种情况下个体适应的是"平均"生境，此时扩散前交配可将亲缘个体的基因带入新种群，从而带来演化收益。当扩散速率较高且种群规模较大时，本地适应与亲缘结构均会消失，此时扩散与交配的时间次序可能成为（近乎）中性的性状。