Selective differentiation during the colonization and establishment of a newly invasive species

The potential for rapid evolution in invasive species makes them useful for studying adaptive responses of populations to novel environments. However, phenotypic divergence during invasion is not necessarily due to selection, but may be a product of neutral processes resulting from population bottlenecks during colonization and range expansion. We investigated phenotypic adaptation during the establishment and range expansion of the invasive bunchgrass, slender false brome (Brachypodium sylvaticum; Poaceae). Utilizing a novel approach, we made robust comparisons of functional traits using genetic similarity based on unique alleles to determine the genetic probability of contribution from native source regions, and integrated these probabilities into our QST‐FST comparisons for twelve physiological and anatomical traits associated with drought stress in the introduced range. Our results indicate phenotypic divergence greater than neutral expectations in five traits between native and inv...入侵物种具有快速演化的潜能，这使其成为探究种群对新生环境适应性响应的理想实验体系。然而，入侵过程中的表型分化未必由选择作用驱动，也可能源于定殖与分布范围扩张阶段种群瓶颈所引发的中性演化过程。本研究针对入侵丛生草本植物细叶假雀麦（Brachypodium sylvaticum; Poaceae）在定殖与分布范围扩张过程中的表型适应性展开探究。本研究采用全新方法，基于独特等位基因计算遗传相似性，以此评估各群体来自本土源区域的遗传贡献概率，并将该概率纳入针对入侵区域内12个与干旱胁迫相关的生理及解剖功能性状的QST-FST比较分析。研究结果显示，本土种群与入侵种群间有5个性状的表型分化程度高于中性演化预期...