Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, 9747AG, The Netherlands.
Institute of Biology I, University of Freiburg, Freiburg im Breisgau, 79104, Germany.
Nat Commun. 2023 Oct 26;14(1):6805. doi: 10.1038/s41467-023-42607-6.
The parental roles of males and females differ considerably between and within species. By means of individual-based evolutionary simulations, we strive to explain this diversity. We show that the conflict between the sexes creates a sex bias (towards maternal or paternal care), even if the two sexes are initially identical. When including sexual selection, there are two outcomes: either female mate choice and maternal care or no mate choice and paternal care. Interestingly, the care pattern drives sexual selection and not vice versa. Longer-term simulations exhibit rapid switches between alternative parental care patterns, even in constant environments. Hence, the evolutionary lability of sex roles observed in phylogenetic studies is not necessarily caused by external changes. Overall, our findings are in striking contrast to the predictions of mathematical models. We show that the discrepancies are caused by transient within-sex polymorphisms in parental strategies, a factor largely neglected in current sex-role theory.
雌雄个体在不同物种和同一物种内的亲代角色差异很大。通过基于个体的进化模拟，我们努力解释这种多样性。我们表明，即使两性最初是相同的，性别之间的冲突也会导致性别偏向（偏向于母性或父性照顾）。当包括性选择时，有两种结果：要么是雌性的配偶选择和母性照顾，要么是没有配偶选择和父性照顾。有趣的是，照顾模式驱动性选择，而不是相反。长期模拟显示，即使在恒定环境中，替代亲代照顾模式也会迅速切换。因此，系统发育研究中观察到的性别角色的进化不稳定性不一定是由外部变化引起的。总的来说，我们的研究结果与数学模型的预测形成鲜明对比。我们表明，差异是由亲代策略中的暂时的同性别多态性引起的，这一因素在当前的性别角色理论中被大大忽视。
