Nature Ecology & Evolution ( IF 16.8 ) Pub Date : 2020-09-07 , DOI: 10.1038/s41559-020-01286-y Daniel M Lyons 1 , Zhengting Zou 1 , Haiqing Xu 1 , Jianzhi Zhang 1
Patterns of epistasis and shapes of fitness landscapes are of wide interest because of their bearings on a number of evolutionary theories. The common phenomena of slowing fitness increases during adaptations and diminishing returns from beneficial mutations are believed to reflect a concave fitness landscape and a preponderance of negative epistasis. Paradoxically, fitness decreases tend to decelerate and harm from deleterious mutations shrinks during the accumulation of random mutations—patterns thought to indicate a convex fitness landscape and a predominance of positive epistasis. Current theories cannot resolve this apparent contradiction. Here, we show that the phenotypic effect of a mutation varies substantially depending on the specific genetic background and that this idiosyncrasy in epistasis creates all of the above trends without requiring a biased distribution of epistasis. The idiosyncratic epistasis theory explains the universalities in mutational effects and evolutionary trajectories as emerging from randomness due to biological complexity.
中文翻译:
异质性上位性在突变效应和进化轨迹中创造了普遍性。
上位性模式和适应性景观的形状受到广泛关注,因为它们与许多进化理论有关。人们认为,在适应过程中减缓适应性增加和有益突变的回报减少的常见现象反映了凹适应性景观和负上位性占优势。矛盾的是,在随机突变的积累过程中,适应性下降往往会减速,有害突变造成的伤害也会减少——这种模式被认为表明适应性呈凸状,并且正上位性占优势。目前的理论无法解决这个明显的矛盾。这里,我们表明,突变的表型效应根据特定的遗传背景而有很大差异,并且上位性的这种特质产生了上述所有趋势,而不需要上位性的偏向分布。特殊上位性理论解释了由于生物复杂性而从随机性中出现的突变效应和进化轨迹的普遍性。