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

AbstractWhy 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., Usage notesCodeforDryadZip directory containing R code and simulation results associated with paper (including supplementary figures). For details on running the simulations, see readme.txt in directory.

摘要：有性生殖为何能演化成为广泛存在的生殖模式，始终是进化生物学领域的核心未解难题之一。尽管已有研究表明，在宿主-寄生虫互作场景下，更高频率的有性生殖与重组能够得以演化（即有性生殖的红皇后假说（Red Queen hypothesis）），但这类研究大多假定感染与抗性由多个基因位点（locus，复数形式为loci）介导调控。但现有数据显示，抗原呈递与识别过程通常仅由单个主要基因位点介导。本研究构建了一个模型：其中宿主-寄生虫互作仅由单个基因位点介导，而第二个基因位点则受到定向选择（directional selection）的作用。尽管这两个基因对个体适合度（fitness）的影响相互独立，但我们的研究结果表明，在能够改变遗传混合速率的修饰基因（modifier gene）位点上，更高频率的有性生殖与重组会受到正向选择青睐。这一结果的产生源于有限种群中存在的选择干涉现象——即希尔-罗伯逊效应（Hill-Robertson effect），该效应同样会对有性生殖产生正向选择。本研究结果表明，红皇后假说（Red Queen hypothesis）或许可以通过提供一种持续性选择形式来解释有性生殖的演化：这类持续性选择会干扰其他基因位点上的定向选择，进而对有性生殖与重组产生正向选择优势。

使用说明：本Dryad压缩包目录包含与本论文相关的R语言代码与模拟结果（含补充图表）。若需了解模拟运行的详细步骤，请参阅目录内的readme.txt文件。