The influence of landscape on gene flow in the eastern massasauga rattlesnake (Sistrurus c. catenatus): insight from computer simulations

Understanding how gene flow shapes contemporary population structure requires the explicit consideration of landscape composition and configuration. New landscape genetic approaches allow us to link such heterogeneity to gene flow within and among populations. However, the attribution of cause is difficult when landscape features are spatially correlated, or when genetic patterns reflect past events. We use spatial Bayesian clustering and landscape resistance analysis to identify the landscape features that influence gene flow across two regional populations of the eastern massasauga rattlesnake, Sistrurus c. catenatus. Based on spatially explicit simulations, we inferred how habitat distribution modulates gene flow and attempted to disentangle the effects of spatially confounded landscape features. We found genetic clustering across one regional landscape but not the other, and also local differences in the effect of landscape on gene flow. Beyond the effects of isolation-by-distance, ...

要理解基因流如何塑造当代种群结构，需明确考量景观的组成与构型。新兴的景观遗传学方法可将这类景观异质性与种群内部及种群间的基因流建立关联。然而，当景观要素在空间上存在相关性，或遗传格局反映了历史事件时，因果归因颇具难度。本研究采用空间贝叶斯聚类（spatial Bayesian clustering）与景观阻力分析（landscape resistance analysis）方法，识别出影响东部猪鼻响尾蛇（Sistrurus c. catenatus）两个区域种群间基因流的景观要素。基于空间显式模拟，本研究推断生境分布如何调控基因流，并试图厘清空间混淆的景观要素所产生的效应。研究发现，其中一个区域景观存在遗传聚类现象，而另一区域则无此现象；同时，景观对基因流的影响存在局域差异。除距离隔离效应之外，……