Organisms are expected to respond to changing environmental conditions through local adaptation, range shift or local extinction. The process of local adaptation can occur by genetic changes or phenotypic plasticity, and becomes especially relevant when dispersal abilities or possibilities are somehow constrained. For genetic changes to occur, mutations are the ultimate source of variation and the mutation rate in terms of a mutator locus can be subject to evolutionary change. Recent findings suggest that the evolution of the mutation rate in a sexual species can advance invasion speed and promote adaptation to novel environmental conditions. Following this idea, this work uses an individual-based model approach to investigate if the mutation rate can also evolve in a sexual species experiencing different conditions of directional climate change, under different scenarios of colored stochastic environmental noise, probability of recombination and of beneficial mutations. The color of the noise mimicked investigating the evolutionary dynamics of the mutation rate in different habitats. The results suggest that the mutation rate in a sexual species experiencing directional climate change scenarios can evolve and reach relatively high values mainly under conditions of complete linkage of the mutator locus and the adaptation locus. In contrast, when they are unlinked, the mutation rate can slightly increase only under scenarios where at least 50% of arising mutations are beneficial and the rate of environmental change is relatively fast. This result is robust under different scenarios of stochastic environmental noise, which supports the observation of no systematic variation in the mutation rate among organisms experiencing different habitats. Given that 50% beneficial mutations may be an unrealistic assumption, and that recombination is ubiquitous in sexual species, the evolution of an elevated mutation rate in a sexual species experiencing directional climate change might be rather unlikely. Furthermore, when the percentage of beneficial mutations and the population size are small, sexual species (especially multicellular ones) producing few offspring may be expected to react to changing environments not by adaptive genetic change, but mainly through plasticity. Without the ability for a plastic response, such species may become – at least locally – extinct.

中文翻译：

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即使在快速的环境变化下，突变率也不会在有性物种中进化

人们期望有机体通过局部适应，范围变化或局部灭绝对不断变化的环境条件做出反应。局部适应的过程可以通过遗传变化或表型可塑性发生，并且在分散能力或可能性受到某种方式限制时变得尤为重要。对于发生的遗传变化，突变是变异的最终来源，就变异位点而言，变异率可能会发生进化变化。最近的发现表明，有性物种中突变率的演变可以提高入侵速度并促进对新环境条件的适应。按照这个想法，这项工作使用了基于个体的模型方法来研究突变率是否也可以在经历不同方向性气候变化条件的有性物种中进化，在有色随机环境噪声，重组概率和有益突变的不同场景下。噪音的颜色模仿了不同生境中突变率的进化动态。结果表明，主要在突变位点和适应位点完全连锁的条件下，经历定向气候变化情景的有性物种的突变率可以进化并达到相对较高的值。相反，当它们不关联时，仅在至少50％的产生突变是有益的且环境变化速率相对较快的情况下，突变率才可以稍微增加。在随机环境噪声的不同情况下，此结果是可靠的，这支持观察到在经历不同生境的生物之间突变率没有系统变化的现象。考虑到50％的有益突变可能是不切实际的假设，并且重组在有性物种中无处不在，因此在经历定向气候变化的有性物种中，突变率升高的演变可能不太可能。此外，当有益突变的百分比和种群规模较小时，可以预期产生很少后代的有性物种（特别是多细胞物种）对变化的环境的反应不是通过适应性遗传改变，而主要是通过可塑性。没有可塑性反应的能力，此类物种至少在局部地区可能灭绝。考虑到50％的有益突变可能是不现实的假设，并且重组在有性物种中无处不在，因此在经历定向气候变化的有性物种中，突变率升高的发展可能不太可能。此外，当有益突变的百分比和种群规模较小时，可以预期产生很少后代的有性物种（特别是多细胞物种）对变化的环境的反应不是通过适应性遗传改变，而主要是通过可塑性。没有可塑性反应的能力，此类物种至少在局部地区可能灭绝。考虑到50％的有益突变可能是不现实的假设，并且重组在有性物种中无处不在，因此在经历定向气候变化的有性物种中，突变率升高的发展可能不太可能。此外，当有益突变的百分比和种群规模较小时，可以预期产生很少后代的有性物种（特别是多细胞物种）对变化的环境的反应不是通过适应性遗传改变，而主要是通过可塑性。没有可塑性反应的能力，此类物种至少在局部地区可能灭绝。当有益突变的百分比和种群规模较小时，可以预期产生很少后代的有性物种（特别是多细胞物种）对变化的环境的反应不是通过适应性遗传改变，而主要是通过可塑性。没有可塑性反应的能力，此类物种至少在局部地区可能灭绝。当有益突变的百分比和种群规模较小时，可以预期产生很少后代的有性物种（特别是多细胞物种）对变化的环境的反应不是通过适应性遗传改变，而主要是通过可塑性。没有可塑性反应的能力，此类物种至少在局部地区可能灭绝。