Data from: The red queen coupled with directional selection favors the evolution of sex

<b>Abstract</b><br/>Why sexual reproduction has evolved to be such a widespread mode of reproduction remains a major question in evolutionary biology. While previous studies have shown that increased sex and recombination can evolve in the presence of host-parasite interactions (the “Red Queen hypothesis” for sex), many of these studies have assumed that multiple loci mediate infection versus resistance. Data suggest, however, that a major locus is typically involved in antigen presentation and recognition. Here, we explore a model where only one locus mediates host-parasite interactions, but a second locus is subject to directional selection. Even though the effects of these genes on fitness are independent, we show that increased rates of sex and recombination are favored at a modifier gene that alters the rate of genetic mixing. This result occurs because of selective interference that occurs in finite populations (the “Hill-Robertson effect”), which also favors sex. These results suggest that the Red Queen hypothesis may help to explain the evolution of sex by contributing a form of persistent selection, which interferes with directional selection at other loci and thereby favors sex and recombination.

<b>摘要</b><br/>有性生殖为何进化为如此广泛的繁殖方式，仍是进化生物学中的核心问题之一。尽管此前研究表明，在宿主-寄生虫相互作用（有性生殖的“红皇后假说”（Red Queen hypothesis））存在的情况下，更高频率的有性生殖与重组可能得以进化，但多数此类研究均假设感染与抗性由多基因座（locus）介导。然而，数据显示，抗原呈递与识别通常由一个主基因座主导。本研究构建了一个模型：仅一个基因座介导宿主-寄生虫相互作用，而另一个基因座受定向选择影响。尽管这些基因对适合度的效应相互独立，但我们发现，在能够改变遗传混合速率的修饰基因（modifier gene）位点，更高的有性生殖与重组率更受青睐。这一结果源于有限种群中存在的选择性干扰（Hill-Robertson效应）——该效应同样有利于有性生殖。这些结果表明，红皇后假说可通过提供一种持续选择的形式，干扰其他基因座上的定向选择，进而促进有性生殖与重组的进化，从而为有性生殖的进化机制提供解释。