Data from: Loss of sexual recombination and segregation is associated with increased diversification in evening primroses

AbstractThe loss of sexual recombination and segregation in asexual organisms has been portrayed as an irreversible process that commits asexually-reproducing lineages to reduced diversification. We test this hypothesis by estimating rates of speciation, extinction, and transition between sexuality and functional asexuality in the evening primroses. Specifically, we estimate these rates using the recently developed BiSSE (Binary State Speciation and Extinction) phylogenetic comparative method, which employs maximum likelihood and Bayesian techniques. We infer that net diversification rates (speciation minus extinction) in functionally asexual evening primrose lineages are roughly eight times faster than diversification rates in sexual lineages, largely due to higher speciation rates in asexual lineages. We further reject the hypothesis that a loss of recombination and segregation is irreversible because the transition rate from functional asexuality to sexuality is significantly greater than zero.and in fact exceeded the reverse rate. These results provide the first empirical evidence in support of the alternative theoretical prediction that asexual populations should instead diversify more rapidly than sexual populations because they are free from the homogenizing effects of sexual recombination and segregation. Although asexual reproduction may often constrain adaptive evolution, our results show that the loss of recombination and segregation need not be an evolutionary dead-end in terms of diversification of lineages., Usage notesOnagraceae TREEBASE fileML_analysesThis zip directory gives the BiSSE maximum likelihood analyses reported in Table S3.MCMC_analysesThis zip directory gives the full MCMC results and the R code that generated the data underlying Figure 3, Figure S1, Figure S3, Table 1, and Table S2.

摘要：无性生物有性重组与分离过程的丧失，长期以来被视为一个不可逆转的过程，会导致无性繁殖类群的多样化水平降低。本研究以月见草（evening primroses）为研究对象，通过估算其物种形成速率、灭绝速率以及有性生殖与功能性无性生殖之间的转换速率，对这一假说进行检验。具体而言，我们采用新近开发的二元状态物种形成与灭绝分析方法（BiSSE，Binary State Speciation and Extinction）这一系统发育比较方法进行速率估算，该方法整合了最大似然法与贝叶斯分析技术。我们推断，功能性无性生殖的月见草类群的净多样化速率（物种形成速率减去灭绝速率）约为有性生殖类群的8倍，这一差异主要源于无性类群更高的物种形成速率。我们进一步推翻了"重组与分离过程的丧失不可逆转"这一假说：从功能性无性生殖向有性生殖的转换速率显著大于0，实际上甚至高于反向转换速率。本研究结果首次提供了经验证据，支持另一项理论预测：由于无性生殖种群不受有性重组与分离过程的同质化效应影响，其多样化速率应高于有性生殖种群。尽管无性生殖通常会限制适应性进化，但我们的研究结果表明，从类群多样化的角度来看，重组与分离过程的丧失未必会成为进化死胡同。

使用说明：
柳叶菜科（Onagraceae）树库（TREEBASE）文件
ML_analyses：此压缩文件夹包含了表S3中报告的BiSSE最大似然分析结果。
MCMC_analyses：此压缩文件夹包含了完整的马尔可夫链蒙特卡洛（MCMC，Markov Chain Monte Carlo）结果，以及用于生成图3、图S1、图S3、表1和表S2所需数据的R代码。