Patterns of speciation and parallel genetic evolution under adaptation from standing variation
Patterns of speciation and parallel genetic evolution under adaptation from standing variation
复制标题
常备变异适应下的物种形成模式和平行遗传进化
DOI：
--
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Kentrez Thompson
中科院分区：
文献类型：
--
作者：
Kentrez Thompson;Matthew M. Osmond;D. Schluter;Kentrez Thompson
当孤立的种群适应新的环境时，它们可能使用相同或21个不同的等位基因。如果22个种群共享祖先的遗传变异，那么使用相同的等位基因--平行遗传进化--的可能性越来越大。在这里，我们调查了23个条件下，人口经历平行的遗传进化，从常设变异24和相关的影响，通过环境特异性杂交健身的物种形成。使用25计算机模拟，我们发现，人口适应相同的环境往往会固定26相同的等位基因从常设变异，除非有一个不足或过量的27变异的创始人口。我们还发现，随着选择从完全平行转向发散，平行遗传适应的程度以比线性更快的速度下降。这种平行性的迅速下降是因为30个种群之间看似很小的环境差异对应于互惠等位基因比例的急剧下降。最后，我们表明，从站立的变化适应减少了表型32分离方差的杂交种下的平行和分歧的选择。在平行33选择下，亲本群体固定了在杂种中不分离的相同等位基因。此外，与来自新突变的适应相比，来自现存变异的适应通过更大数量的等位基因进行，具有更小的单独影响-这进一步降低了分离方差，即使在趋异选择下。当亲本适应相似的环境时，这种降低的分离方差37提高了平均杂种适应度，但在发散适应下降低了平均杂种适应度。因此，从常设变异39适应通过平行选择预先形成物种，并通过趋异选择促进物种形成。40
When isolated populations adapt to novel environments, they may do so using the same or 21 different alleles. Use of the same alleles — parallel genetic evolution — is increasingly likely if 22 populations have shared ancestral standing genetic variation. Here, we investigate the 23 conditions under which populations undergo parallel genetic evolution from standing variation 24 and the associated implications for speciation via environment-specific hybrid fitness. Using 25 computer simulations, we find that populations adapting to identical environments tend to fix 26 the same alleles from standing variation unless there is a deficient or excess amount of 27 variation in the founding population. We also find that the degree of parallel genetic adaptation 28 decreases faster-than-linearly as selection deviates from fully parallel toward divergent. This 29 rapid decrease in parallelism occurs because seemingly small environmental differences among 30 populations correspond to steep reductions in the fraction of alleles that are mutually 31 beneficial. Lastly, we show that adaptation from standing variation reduces the phenotypic 32 segregation variance of hybrids under both parallel and divergent selection. Under parallel 33 selection, parental populations fix the same alleles which do not segregate in hybrids. In 34 addition, adaptation from standing variation proceeds via a greater number of alleles with 35 individually smaller effects than when adaptation is from new mutation — this further reduces 36 segregation variance even under divergent selection. This reduced segregation variance 37 improves mean hybrid fitness when parents adapt to similar environments but reduces mean 38 hybrid fitness under divergent adaptation. Therefore adaptation from standing variation 39 forestalls speciation via parallel selection and promotes speciation via divergent selection. 40
DOI：
10.1017/s0016672300032547
发表时间：
1994-08
期刊：
Genetical research
影响因子：
--
作者：
M. Slatkin;R. Lande
通讯作者：
M. Slatkin;R. Lande
霍尔丹筛法和对常设遗传变异的适应。
影响因子：
3.3
作者：
Orr,HA;Betancourt,AJ
通讯作者：
Betancourt,AJ