Insights from Fisher's geometric model on the likelihood of speciation under different histories of environmental change
Insights from Fisher's geometric model on the likelihood of speciation under different histories of environmental change
复制标题
费舍尔几何模型对不同环境变化历史下物种形成可能性的见解
DOI：
10.1111/evo.14032
复制
发表时间：
2020
期刊：
影响因子：
3.3
通讯作者：
Otto Sarah P.
中科院分区：
文献类型：
--
作者：
Yamaguchi Ryo;Otto Sarah P.
通过不相容的遗传变化的积累而形成的新物种被认为是基于生态学的不同自然选择或突变发生的顺序的结果，即使在相似的选择压力下也会导致不同的进化轨迹。有越来越多的证据支持生态物种形成和突变顺序物种形成，但不同的环境情景如何影响物种形成的速度仍然有待探索。我们使用一个简单的模型，优化选择多个性状（“费舍尔几何模型”），以确定在不断变化的环境中产生遗传不相容性的条件。我们发现，不相容性很可能在适应不同环境的孤立种群中积累，与生态物种形成一致。当孤立的种群面临类似的新环境时，也会出现不相容性;当环境迅速变化并有利于大效应突变的积累时，这些突变顺序物种形成的情况特别可能。此外，我们发现，同倍体杂交物种很可能发生时，新的环境中出现的亲本环境之间，或当父母的人口积累了一段时间的快速适应后的大效应突变。我们的研究结果表明，快速的环境变化时期是特别有利于物种形成，特别是突变顺序或混合物种形成。
The formation of new species via the accumulation of incompatible genetic changes is thought to result either from ecologically based divergent natural selection or the order by which mutations happen to arise, leading to different evolutionary trajectories even under similar selection pressures. There is growing evidence in support of both ecological speciation and mutation-order speciation, but how different environmental scenarios affect the rate of species formation remains underexplored. We use a simple model of optimizing selection on multiple traits (“Fisher's geometric model”) to determine the conditions that generate genetic incompatibilities in a changing environment. We find that incompatibilities are likely to accumulate in isolated populations adapting to different environments, consistent with ecological speciation. Incompatibilities also arise when isolated populations face a similar novel environment; these cases of mutation-order speciation are particularly likely when the environment changes rapidly and favors the accumulation of large-effect mutations. In addition, we find that homoploid hybrid speciation is likely to occur either when new environments arise in between the parental environments or when parental populations have accumulated large-effect mutations following a period of rapid adaptation. Our results indicate that periods of rapid environmental change are particularly conducive to speciation, especially mutation-order or hybrid speciation.