Manier Mollie K, Arnold Stevan J
Department of Zoology, 3029 Cordley Hall, Oregon State University, Corvallis, OR 97331-2914, USA.
Proc Biol Sci. 2006 Dec 7;273(1604):3001-9. doi: 10.1098/rspb.2006.3678.
Identifying ecological factors associated with population genetic differentiation is important for understanding microevolutionary processes and guiding the management of threatened populations. We identified ecological correlates of several population genetic parameters for three interacting species (two garter snakes and an anuran) that occupy a common landscape. Using multiple regression analysis, we found that species interactions were more important in explaining variation in population genetic parameters than habitat and nearest-neighbour characteristics. Effective population size was best explained by census size, while migration was associated with differences in species abundance. In contrast, genetic distance was poorly explained by the ecological correlates that we tested, but geographical distance was prominent in models for all species. We found substantially different population dynamics for the prey species relative to the two predators, characterized by larger effective sizes, lower gene flow and a state of migration-drift equilibrium. We also identified an escarpment formed by a series of block faults that serves as a barrier to dispersal for the predators. Our results suggest that successful landscape-level management should incorporate genetic and ecological data for all relevant species, because even closely associated species can exhibit very different population genetic dynamics on the same landscape.
识别与种群遗传分化相关的生态因素对于理解微观进化过程和指导濒危种群的管理至关重要。我们确定了占据共同景观的三种相互作用物种（两种束带蛇和一种无尾目动物）的几个种群遗传参数的生态关联因素。通过多元回归分析，我们发现物种间相互作用在解释种群遗传参数的变异方面比栖息地和最近邻特征更为重要。有效种群大小最好由普查规模来解释，而迁移与物种丰度的差异有关。相比之下，我们所测试的生态关联因素对遗传距离的解释能力较差，但地理距离在所有物种的模型中都很突出。我们发现猎物物种相对于两种捕食者具有截然不同的种群动态，其特征是有效大小更大、基因流更低以及处于迁移 - 漂变平衡状态。我们还确定了由一系列块状断层形成的悬崖，它对捕食者的扩散起到了屏障作用。我们的结果表明，成功的景观层面管理应纳入所有相关物种的遗传和生态数据，因为即使是紧密相关的物种在同一景观上也可能表现出非常不同的种群遗传动态。
