The effect of sexual selection on adaptation and extinction under increasing temperatures
The effect of sexual selection on adaptation and extinction under increasing temperatures
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DOI：
10.1098/rspb.2018.0303
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发表时间：
2018-04-25
影响因子：
4.7
通讯作者：
Knell, Robert J.
中科院分区：
文献类型：
--
作者：
Parrett, Jonathan M.;Knell, Robert J.
据报道，在暴露于新环境时，强烈的性选择既可以增强也可以阻碍种群的适应能力和持久性。因此，性选择如何影响种群在压力下的适应和持久性仍然存在广泛争议。在这里，我们提出了两项实证研究，研究性选择对暴露于稳定或逐渐升高的温度的印度谷蛾种群的适应性影响。当面临气温升高时，与经历弱性选择的种群相比，强性选择与繁殖力和后代存活率的增加有关，这表明性选择通过有利于有益等位基因来驱动适应性进化。然而，当温度变得过高时，强烈的性选择并没有推迟灭绝。通过在适应性测定中操纵个体的交配机会，我们能够独立于种群水平性选择的影响来评估多重交配的影响，并发现一妻多夫对那些在弱性选择中进化的种群在气温升高的情况下的繁殖力和后代存活率具有积极影响。在稳定的温度下，强烈的性选择会带来一些好处，但这些好处在整个实验中并不一致，可能反映了稳定和定向选择下性选择的成本和收益的变化。这些结果表明，性选择可以提供应对气候变化的缓冲，并提高不断变化的环境中的适应率。然而，当环境变化相对较快时，性选择的这些积极影响可能太小，无法保护种群并延迟灭绝。
Strong sexual selection has been reported to both enhance and hinder the adaptive capacity and persistence of populations when exposed to novel environments. Consequently, how sexual selection influences population adaption and persistence under stress remains widely debated. Here, we present two empirical investigations of the fitness consequences of sexual selection on populations of the Indian meal moth, Plodia interpunctella, exposed to stable or gradually increasing temperatures. When faced with increasing temperatures, strong sexual selection was associated with both increased fecundity and offspring survival compared with populations experiencing weak sexual selection, suggesting sexual selection acts to drive adaptive evolution by favouring beneficial alleles. Strong sexual selection did not, however, delay extinction when the temperature became excessively high. By manipulating individuals' mating opportunities during fitness assays, we were able to assess the effect of multiple mating independently from the effect of population-level sexual selection, and found that polyandry has a positive effect on both fecundity and offspring survival under increasing temperatures in those populations evolving with weak sexual selection. Within stable temperatures, there were some benefits from strong sexual selection but these were not consistent across the entire experiment, possibly reflecting changing costs and benefits of sexual selection under stabilizing and directional selection. These results indicate that sexual selection can provide a buffer against climate change and increase adaptation rates within a continuously changing environment. These positive effects of sexual selection may, however, be too small to protect populations and delay extinction when environmental changes are relatively rapid.