Data from: Temperature can shape a cline in polyandry, but only genetic variation can sustain it over time

Multiple mating by females (polyandry) is a widespread behavior occurring in diverse taxa, species, and populations. Polyandry can also vary widely within species, and individual populations, so that both monandrous and polyandrous females occur together. Genetic differences can explain some of this intraspecific variation in polyandry, but environmental factors are also likely to play a role. One environmental factor that influences many fundamental biological processes is temperature. Higher temperatures have been shown to directly increase remating in laboratory studies of insects. In the longer term, high temperature could also help to drive the evolution of larger-scale patterns of behavior by changing the context-dependent balance of costs and benefits of polyandry across environments. We examined the relative influence of rearing and mating temperatures on female remating in populations of Drosophila pseudoobscura that show a latitudinal cline in polyandry in nature, using a range of ecologically relevant temperatures. We found that females of all genotypes remated more at cooler temperatures, which fits with the observation of higher average frequencies of polyandry at higher latitudes in this species. However, the impact of temperature was outweighed by the strong genetic control of remating in females in this species. It is likely that genetic factors provide the primary explanation for the latitudinal cline in polyandry in this species.雌性多次交配（polyandry，一妻多夫制）是广泛分布于各类群、物种及种群中的行为。一妻多夫制在物种乃至单个种群内部也存在显著变异，致使单夫制与一妻多夫制雌性个体共存于同一群体。遗传差异可解释部分种内一妻多夫制的变异，但环境因素同样可能发挥作用。影响诸多基础生物学过程的环境因素之一为温度，已有昆虫实验室研究表明，较高温度可直接提升雌性的再次交配频率；从长期来看，高温还可通过改变不同环境下一妻多夫制的代价与收益的情境依赖性平衡，推动行为模式的大范围演化。本研究以天然状态下一妻多夫制呈现纬度渐变群的伪暗果蝇（Drosophila pseudoobscura）种群为研究对象，设置一系列生态相关的温度梯度，探讨饲养温度与交配温度对雌性再次交配行为的相对影响。研究发现，所有基因型的雌性个体在较低温度下的再次交配频率更高，这与该物种在高纬度地区平均一妻多夫制频率更高的观测结果相符；然而，该物种雌性再次交配行为受到的强遗传调控作用，其影响远超过温度带来的效应，综上，遗传因素或可解释该物种一妻多夫制纬度渐变群的主要成因。