Data from: The devil is in the details: genetic variation in introduced populations and its contributions to invasion

The influence of genetic variation on invasion success has captivated researchers since the start of the field of invasion genetics 50 years ago. We review the history of work on this question and conclude that genetic variation – as surveyed with molecular markers – appears to shape invasion rarely. Instead, there is a significant disconnect between marker assays and ecologically relevant genetic variation in introductions. We argue that the potential for adaptation to facilitate invasion will be shaped by the details of genotypes affecting phenotypes, and we highlight three areas in which we see opportunities to make powerful new insights. 1) The genetic architecture of adaptive variation. Traits shaped by large effect alleles may be strongly impacted by founder events but likely to respond to selection when genetic drift is strong. Large effect loci may be especially relevant for traits involved in biotic interactions. 2) Cryptic genetic variation exposed during invasion. Introductions have strong potential to uncover masked variation due to alterations in genetic and ecological environments. 3) Genetic interactions during admixture of multiple source populations. As divergence among sources increases, positive followed by increasingly negative effects of admixture should be expected. Though generally hypothesized to be beneficial during invasion, admixture is most often reported among sources of intermediate divergence, supporting the possibility that incompatibilities among divergent source populations might be limiting their introgression. Finally, we note that these details of invasion genetics can be coupled with comparative demographic analyses to link genetic changes to the evolution of invasiveness itself.自50年前入侵遗传学（invasion genetics）这一研究领域诞生以来，遗传变异对生物入侵成功的影响便一直牵动着研究者的目光。我们对该问题的相关研究历史进行了系统综述，最终得出结论：通过分子标记（molecular marker）手段所检测到的遗传变异，似乎极少对生物入侵过程起到塑造作用。与之形成鲜明反差的是，在生物引种过程中，分子标记检测实验与生态相关的遗传变异之间存在显著脱节。 我们认为，助力生物入侵的适应潜力，将由影响表型的基因型细节所决定，并着重指出了三个有望取得突破性新发现的研究方向： 1） 适应性变异的遗传架构（genetic architecture）。由大效应等位基因调控的性状，可能会受到奠基者事件的强烈影响，但在遗传漂变较强的情境下，这类性状往往更易响应选择；大效应基因座（locus）或许与生物互作相关性状的关联尤为紧密。 2） 入侵过程中暴露的隐性遗传变异。由于遗传与生态环境发生改变，生物引种过程极有可能揭示原本被掩盖的遗传变异。 3） 多重源种群混合过程中的遗传互作。随着源种群间分化程度的提升，种群混合将依次呈现出正向效应，随后转为愈发显著的负向效应。尽管学界普遍推测种群混合有助于生物入侵，但现有研究中混合事件多发生于分化程度中等的源种群之间，这支持了"分化程度较高的源种群之间可能存在生殖不相容性，从而限制了其基因渐渗（introgression）"这一假说。 最后，我们指出，可将入侵遗传学的上述研究细节与比较种群人口统计学分析相结合，以将遗传变化与入侵性本身的演化过程直接关联起来。