Selection on parental performance opposes selection for larger body mass in a wild population of blue tits.
Selection on parental performance opposes selection for larger body mass in a wild population of blue tits.
复制标题
在野生蓝山雀种群中，对父母表现的选择与对较大体重的选择相反。
DOI：
10.1111/evo.13169
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Thomson CE
中科院分区：
文献类型：
--
作者：
Thomson CE
许多分类群中有大量证据表明体型存在正向选择，但微进化变化的证据却很少。在许多物种中，体型的变化部分是由父母的行为决定的，因此对停滞的拟议解释是直接影响和父母影响之间存在负遗传相关性。因此，选择增加体型的基因将导致亲本效应的相关下降，从而减少下一代的体型。我们表明，这些论点隐含地假设父母的照顾是免费的，并且包括成本会改变解释停滞所需的预测遗传结构。使用大量交叉饲养的蓝山雀种群，我们估计了亲代对体重的直接选择效应，并表明它是负的。负选择与父母照顾的成本是一致的，主要是通过减少当前的生育力而不是生存率来发挥作用。在这些条件下，直接效应和亲代效应之间的适度负遗传相关性可能导致进化停滞。这与假设护理是免费的时所需的令人难以置信的极端相关性形成鲜明对比。因此，我们强调正确解释对跨代性状的完全选择的重要性。
There is abundant evidence in many taxa for positive directional selection on body size, and yet little evidence for microevolutionary change. In many species, variation in body size is partly determined by the actions of parents, so a proposed explanation for stasis is the presence of a negative genetic correlation between direct and parental effects. Consequently, selecting genes for increased body size would result in a correlated decline in parental effects, reducing body size in the following generation. We show that these arguments implicitly assume that parental care is cost free, and that including a cost alters the predicted genetic architectures needed to explain stasis. Using a large cross-fostered population of blue tits, we estimate direct selection on parental effects for body mass, and show it is negative. Negative selection is consistent with a cost to parental care, mainly acting through a reduction in current fecundity rather than survival. Under these conditions, evolutionary stasis is possible for moderately negative genetic correlations between direct and parental effects. This is in contrast to the implausibly extreme correlations needed when care is assumed to be cost-free. Thus, we highlight the importance of accounting correctly for complete selection acting on traits across generations.