Department of Biological Science, Florida State University, Tallahassee, Florida, 32306.
Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599.
Evolution. 2019 Apr;73(4):648-660. doi: 10.1111/evo.13691. Epub 2019 Feb 14.
The distribution of resources in space has important consequences for the evolution of dispersal-related traits. Dispersal moderates patterns of gene flow and, consequently, the potential for local adaptation to spatially differentiated resource types. We lack both models and experiments that evaluate how dispersal evolves in landscapes with multiple resources. Here, we investigate the evolution of dispersal in landscapes that contain two resource types that differ in their spatial autocorrelations. Individuals may possess ecological traits that give them a fitness advantage on one or the other resource. We find that resources differing in their spatial autocorrelation select for different optimal dispersal strategies and, further, that some multi-resource landscapes can support the stable coexistence of distinct dispersal strategies. Whether divergence in dispersal strategies between resource specialists occurs depends on the underlying structure of the resources and the degree of linkage between dispersal strategies and ecological specialization. This work indicates that the spatial autocorrelation of resources is an important factor in determining when evolutionary branching is likely to occur, and sheds light on when secondary isolating mechanisms should arise between locally adapted specialists.
资源在空间中的分布对与扩散相关特征的进化有重要影响。扩散缓和了基因流动的模式，从而影响了对空间分化资源类型的局部适应的潜力。我们既缺乏模型，也缺乏实验来评估在具有多种资源的景观中，扩散是如何进化的。在这里，我们研究了在包含两种资源的景观中扩散的进化，这两种资源在空间自相关方面存在差异。个体可能具有使它们在一种或另一种资源上具有适应性优势的生态特征。我们发现，空间自相关不同的资源选择了不同的最优扩散策略，而且，一些多资源景观可以支持不同扩散策略的稳定共存。资源专家之间的扩散策略是否发生分歧，取决于资源的基础结构以及扩散策略和生态特化之间的联系程度。这项工作表明，资源的空间自相关是决定何时可能发生进化分支的一个重要因素，并阐明了在局部适应的专家之间何时应该出现次要隔离机制。
