Theoretical and Experimental Ecology Station (UMR 5371), National Centre for Scientific Research (CNRS), Paul Sabatier University (UPS), 09200 Moulis, France.
Institut Systématique, Evolution, Biodiversité (ISYEB), UMR 7205 Museum d'Histoire Naturelle, CNRS, Sorbonne Université, EPHE, Université des Antilles, F-75005 Paris, France.
Genes (Basel). 2021 Mar 3;12(3):362. doi: 10.3390/genes12030362.
Understanding the functioning of natural metapopulations at relevant spatial and temporal scales is necessary to accurately feed both theoretical eco-evolutionary models and conservation plans. One key metric to describe the dynamics of metapopulations is dispersal rate. It can be estimated with either direct field estimates of individual movements or with indirect molecular methods, but the two approaches do not necessarily match. We present a field study in a large natural metapopulation of the butterfly in Belgium surveyed over three generations using synchronized demographic and genetic datasets with the aim to characterize its genetic structure, its dispersal dynamics, and its demographic stability. By comparing the census and effective population sizes, and the estimates of dispersal rates, we found evidence of stability at several levels: constant inter-generational ranking of population sizes without drastic historical changes, stable genetic structure and geographically-influenced dispersal movements. Interestingly, contemporary dispersal estimates matched between direct field and indirect genetic assessments. We discuss the eco-evolutionary mechanisms that could explain the described stability of the metapopulation, and suggest that destabilizing agents like inter-generational fluctuations in population sizes could be controlled by a long adaptive history of the species to its dynamic local environment. We finally propose methodological avenues to further improve the match between demographic and genetic estimates of dispersal.
了解自然复合种群在相关时空尺度上的功能对于准确为理论生态进化模型和保护计划提供信息是必要的。描述复合种群动态的一个关键指标是扩散率。它可以通过个体运动的直接现场估计或间接的分子方法来估计，但这两种方法不一定匹配。我们在比利时的一个大型蝴蝶自然复合种群中进行了一项实地研究，该种群在三个世代中使用同步的人口统计和遗传数据集进行了调查，目的是描述其遗传结构、扩散动态和人口稳定性。通过比较人口普查和有效种群大小，以及扩散率的估计，我们在多个层面上发现了稳定的证据：没有剧烈历史变化的世代间种群大小的恒定排名、稳定的遗传结构和受地理影响的扩散运动。有趣的是，直接野外和间接遗传评估的当代扩散估计值相匹配。我们讨论了可以解释复合种群稳定性的生态进化机制，并提出了物种对其动态局部环境的长期适应性历史可以控制像世代间种群大小波动这样的不稳定因素的观点。最后，我们提出了一些方法途径，以进一步提高扩散的人口统计和遗传估计之间的匹配程度。
