Creating new evolutionary pathways through bio-invasion: the population genetics of brushtail possums in New Zealand

Rapid increases in global trade and human movement have created novel mixtures of organisms bringing with them the potential to rapidly accelerate the evolution of new forms. The common brushtail possum (Trichosurus vulpecula), introduced into New Zealand from Australia in the 19th Century, is one such species having been sourced from multiple populations in its native range. Here, we combine microsatellite DNA and GIS-based spatial data to show that T.vulpecula originating from at least two different Australian locations exhibit a population structure that is commensurate with their introduction history and which cannot be explained by landscape features alone. Most importantly, we identify a hybrid zone between the two subspecies which appears to function as a barrier to dispersal. When combined with previous genetic, morphological and captive studies, our data suggest that assortative mating between the two subspecies may operate at a behavioural or species recognition level rather t...全球贸易与人类流动的迅猛扩张催生了新颖的生物类群混合格局，为新型生物类群的快速演化提供了潜在契机。19世纪从澳大利亚引入新西兰的普通刷尾负鼠（Trichosurus vulpecula）便是这类物种之一，其引种种群源自原生分布区内的多个自然种群。本研究整合微卫星DNA（microsatellite DNA）与基于地理信息系统（GIS）的空间数据，结果表明，源自澳大利亚至少两个不同地域的普通刷尾负鼠，其种群结构与其引种历史高度契合，且无法仅通过景观特征加以解释。尤为关键的是，我们在两个亚种之间鉴定出一处杂交带，该杂交带似乎对个体扩散构成屏障。结合此前的遗传学、形态学与圈养研究结果，本研究数据显示，两个亚种间的选型交配（assortative mating）可能通过行为识别或物种识别层面的机制发挥作用，而非……