Founding events in species invasions: genetic variation, adaptive evolution, and the role of multiple introductions
Founding events in species invasions: genetic variation, adaptive evolution, and the role of multiple introductions
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DOI：
10.1111/j.1365-294x.2007.03538.x
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发表时间：
2008-01-01
影响因子：
4.9
通讯作者：
Parker, I. M.
中科院分区：
文献类型：
--
作者：
Dlugosch, K. M.;Parker, I. M.
预计入侵物种在建立过程中会遭受遗传多样性的减少，从而降低适应潜力。综合两篇文献综述和两个案例研究的证据，我们解决了以下问题：有多少遗传多样性在入侵中丢失？多次引进能减轻这种损失吗？有证据表明数量性状的多样性丧失了吗？经历过强大瓶颈的入侵者是否表现出适应性进化？在景观尺度上，多种引种是如何影响适应的？我们回顾了80种动物，植物和真菌的研究，量化核分子多样性的引进和源种群。总的来说，有显着的损失，等位基因丰富性和杂合性在引进人口，和大的增益的多样性是罕见的。多次引进的证据与多样性增加有关，等位基因变异似乎在长时间内（类似于100年）增加，这表明基因流动在长期增加多样性中的作用。然后，我们回顾了数量性状多样性的文献，发现广义变异很少下降，在引进，但缺乏直接比较的加性方差。我们对金丝桃入侵的研究说明了多样性减少的种群仍然可以迅速进化。鉴于成功入侵种群中遗传瓶颈的普遍存在以及数量性状适应性进化的潜力，我们认为与创始事件相关的缺点可能被夸大了。然而，我们对成功的入侵者毛蕊花的研究说明了多个引入可能需要时间来混合，而不是作为一个“适应不良的马赛克”而存在，其中特征不以与适应一致的模式分布。我们的结论是，管理限制引进种群之间的基因流动可能会降低适应潜力，但不太可能防止扩张或新的入侵行为的演变。
Invasive species are predicted to suffer from reductions in genetic diversity during founding events, reducing adaptive potential. Integrating evidence from two literature reviews and two case studies, we address the following questions: How much genetic diversity is lost in invasions? Do multiple introductions ameliorate this loss? Is there evidence for loss of diversity in quantitative traits? Do invaders that have experienced strong bottlenecks show adaptive evolution? How do multiple introductions influence adaptation on a landscape scale? We reviewed studies of 80 species of animals, plants, and fungi that quantified nuclear molecular diversity within introduced and source populations. Overall, there were significant losses of both allelic richness and heterozygosity in introduced populations, and large gains in diversity were rare. Evidence for multiple introductions was associated with increased diversity, and allelic variation appeared to increase over long timescales (similar to 100 years), suggesting a role for gene flow in augmenting diversity over the long-term. We then reviewed the literature on quantitative trait diversity and found that broad-sense variation rarely declines in introductions, but direct comparisons of additive variance were lacking. Our studies of Hypericum canariense invasions illustrate how populations with diminished diversity may still evolve rapidly. Given the prevalence of genetic bottlenecks in successful invading populations and the potential for adaptive evolution in quantitative traits, we suggest that the disadvantages associated with founding events may have been overstated. However, our work on the successful invader Verbascum thapsus illustrates how multiple introductions may take time to commingle, instead persisting as a 'mosaic of maladaptation' where traits are not distributed in a pattern consistent with adaptation. We conclude that management limiting gene flow among introduced populations may reduce adaptive potential but is unlikely to prevent expansion or the evolution of novel invasive behaviour.