Colautti Robert I, Lau Jennifer A
Plant Evolutionary Ecology Group, Department for Evolution and Ecology, University of Tübingen, Auf der Morgenstelle 5, D-72076, Tübingen, Germany.
Mol Ecol. 2015 May;24(9):1999-2017. doi: 10.1111/mec.13162. Epub 2015 Apr 20.
Biological invasions are 'natural' experiments that can improve our understanding of contemporary evolution. We evaluate evidence for population differentiation, natural selection and adaptive evolution of invading plants and animals at two nested spatial scales: (i) among introduced populations (ii) between native and introduced genotypes. Evolution during invasion is frequently inferred, but rarely confirmed as adaptive. In common garden studies, quantitative trait differentiation is only marginally lower (3.5%) among introduced relative to native populations, despite genetic bottlenecks and shorter timescales (i.e. millennia vs. decades). However, differentiation between genotypes from the native vs. introduced range is less clear and confounded by nonrandom geographic sampling; simulations suggest this causes a high false-positive discovery rate (>50%) in geographically structured populations. Selection differentials (¦s¦) are stronger in introduced than in native species, although selection gradients (¦β¦) are not, consistent with introduced species experiencing weaker genetic constraints. This could facilitate rapid adaptation, but evidence is limited. For example, rapid phenotypic evolution often manifests as geographical clines, but simulations demonstrate that nonadaptive trait clines can evolve frequently during colonization (two-thirds of simulations). Additionally, QST-FST studies may often misrepresent the strength and form of natural selection acting during invasion. Instead, classic approaches in evolutionary ecology (e.g. selection analysis, reciprocal transplant, artificial selection) are necessary to determine the frequency of adaptive evolution during invasion and its influence on establishment, spread and impact of invasive species. These studies are rare but crucial for managing biological invasions in the context of global change.
生物入侵是“自然”实验，能够增进我们对当代进化的理解。我们在两个嵌套的空间尺度上评估入侵动植物种群分化、自然选择和适应性进化的证据：（i）在引入种群之间；（ii）在本地基因型和引入基因型之间。入侵过程中的进化常常是推断出来的，但很少被证实是适应性的。在共同花园研究中，尽管存在遗传瓶颈和较短的时间尺度（即千年与数十年），引入种群之间的数量性状分化相对于本地种群仅略低（约3.5%）。然而，本地范围与引入范围的基因型之间的分化不太明显，并且受到非随机地理采样的混淆；模拟表明，这在地理结构种群中导致了较高的假阳性发现率（>50%）。引入物种的选择差异（|s|）比本地物种更强，尽管选择梯度（|β|）并非如此，这与引入物种受到较弱的遗传限制一致。这可能有助于快速适应，但证据有限。例如，快速的表型进化通常表现为地理渐变群，但模拟表明，在定殖过程中，非适应性性状渐变群可能经常出现（约三分之二的模拟）。此外，QST - FST研究可能常常误代表征入侵过程中自然选择的强度和形式。相反，进化生态学中的经典方法（如选择分析、 reciprocal移植、人工选择）对于确定入侵过程中适应性进化的频率及其对入侵物种建立、扩散和影响的作用是必要的。这些研究很少见，但对于在全球变化背景下管理生物入侵至关重要。
