Rate of adaptive peak shifts with partial genetic robustness
Rate of adaptive peak shifts with partial genetic robustness
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DOI：
10.1111/j.1558-5646.2007.00166.x
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发表时间：
2007-08-01
期刊：
影响因子：
3.3
通讯作者：
Kim, Yuseob
中科院分区：
文献类型：
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作者：
Kim, Yuseob
如何在个体有害但共同有益的突变中发生适应性进化一直是群体遗传学理论的主要问题之一。在这种情况下，适应通常被描述为种群从Sewall Wright的适应度景观中的一个局部峰值逃到一个更高的峰值。最近的分子遗传学和计算研究表明，遗传鲁棒性可以促进这种峰移。如果新突变的表型表达在遗传稳健性下被抑制，否则有害的突变可以作为中性变异在群体中积累。当健壮性受到环境变化或重大突变的干扰时，这些变异就会暴露在自然选择中。有人认为，这一过程促进了适应，因为在遗传稳健性下富集的等位基因组合可以被积极选择。在这里，我提出了简单的二位点和三位点适应模型，并根据最近的研究提出了部分遗传稳健性。在随机模拟中观察到自适应单倍型固定的等待时间，并与无鲁棒性的期望进行了比较。结果表明，根据遗传鲁棒性的不同，峰移可以延迟或加速。讨论了这些过程的演化意义。
How adaptive evolution occurs with individually deleterious but jointly beneficial mutations has been one of the major problems in population genetics theory. Adaptation in this case is commonly described as a population's escape from a local peak to a higher peak on Sewall Wright's fitness landscape. Recent molecular genetic and computational studies have suggested that genetic robustness can facilitate such peak shifts. If phenotypic expressions of new mutations are suppressed under genetic robustness, mutations that are otherwise deleterious can accumulate in the population as neutral variants. When the robustness is perturbed by an environmental change or a major mutation, these variants become exposed to natural selection. It is argued that this process promotes adaptation because allelic combinations enriched under genetic robustness can then be positively selected. Here, I propose simple two- and three-locus models of adaptation with partial genetic robustness as suggested by recent studies. The waiting time until the fixation of an adaptive haplotype was observed in stochastic simulations and compared to the expectation without robustness. It is shown that peak shifts can be delayed or accelerated depending on the conditions of genetic robustness. The evolutionary significance of these processes is discussed.