Barrett Spencer C H, Colautti Robert I, Eckert Christopher G
Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks St., Toronto, ON, Canada M5S 3B2.
Mol Ecol. 2008 Jan;17(1):373-83. doi: 10.1111/j.1365-294X.2007.03503.x. Epub 2007 Sep 14.
Recent biological invasions provide opportunities to investigate microevolution during contemporary timescales. The tempo and scope of local adaptation will be determined by the intensity of natural selection and the amounts and kinds of genetic variation within populations. In flowering plants, genetic diversity is strongly affected by interactions between reproductive systems and stochastic forces associated with immigration history and range expansion. Here, we explore the significance of reproductive system diversity for contemporary evolution during plant invasion. We focus in particular on how reproductive modes influence the genetic consequences of long-distance colonization and determine the likelihood of adaptive responses during invasion. In many clonal invaders, strong founder effects and restrictions on sexual reproduction limit opportunities for local adaptation. In contrast, adaptive changes to life-history traits should be a general expectation in both outbreeding and inbreeding species. We provide evidence that evolutionary modifications to reproductive systems promote the colonizing ability of invading populations and that reproductive timing is an important target of selection during range expansion. Knowledge of the likelihood and speed at which local adaptation evolves in invasive plants will be particularly important for management practices when evolutionary changes enhance ecological opportunities and invasive spread.
近期的生物入侵为研究当代时间尺度下的微观进化提供了契机。局部适应的速度和范围将由自然选择的强度以及种群内遗传变异的数量和种类决定。在开花植物中，遗传多样性受到生殖系统与移民历史和分布范围扩张相关的随机因素之间相互作用的强烈影响。在此，我们探讨生殖系统多样性对植物入侵过程中当代进化的重要性。我们特别关注生殖模式如何影响远距离定殖的遗传后果，并确定入侵过程中适应性反应的可能性。在许多克隆入侵者中，强烈的奠基者效应和对有性繁殖的限制限制了局部适应的机会。相比之下，对生活史特征的适应性变化在异交和自交物种中都应是普遍预期的。我们提供证据表明，对生殖系统的进化修饰促进了入侵种群的定殖能力，并且生殖时间是分布范围扩张过程中选择的一个重要目标。当进化变化增加生态机会和入侵扩散时，了解入侵植物中局部适应进化的可能性和速度对于管理实践尤为重要。
