Data from: The effect of sex on the repeatability of evolution in different environments

The adaptive function of sex has been extensively studied, while less consideration has been given to the potential downstream consequences of sex on evolution. Here, we investigate one such potential consequence, the effect of sex on the repeatability of evolution. By affecting the repeatability of evolution, sex could have important implications for biodiversity, and for our ability to make predictions about the outcome of environmental change. We allowed asexual and sexual populations of Chlamydomonas reinhardtii to evolve in novel environments and monitored both their change in fitness and variance in fitness after evolution. Sex affected the repeatability of evolution by changing the importance of the effect of selection, chance, and ancestral constraints on the outcome of the evolutionary process. In particular, the effects of sex were highly dependent on the initial genetic composition of the population and on the environment. Given the lack of a consistent effect of sex on repeatability across the environments used here, further studies to dissect in more detail the underlying reasons for these differences as well as studies in additional environments are required if we are to have a general understanding of the effects of sex on the repeatability of evolution.

有性生殖的适应性功能已得到广泛研究，但学界对其对演化过程可能产生的下游效应关注较少。本研究聚焦其中一类潜在效应，即有性生殖对演化可重复性（repeatability of evolution）的影响。通过影响演化可重复性，有性生殖可对生物多样性，以及我们预测环境变化演化结果的能力产生重要影响。我们让莱茵衣藻（Chlamydomonas reinhardtii）的无性生殖种群与有性生殖种群在全新环境中完成演化，并监测了演化后其适合度（fitness）的变化与适合度方差。有性生殖通过改变自然选择、随机事件与祖先约束对演化过程结果的影响权重，作用于演化可重复性。尤为关键的是，有性生殖的效应高度依赖种群的初始遗传组成与所处环境。鉴于本研究所用的不同环境中，有性生殖对演化可重复性的效应并不一致，若要全面理解有性生殖对演化可重复性的影响，还需开展更多研究以详细解析这些差异的内在成因，并在更多环境中开展相关实验。