Data from: Historical mutation rates predict susceptibility to radiation in Chernobyl birds

Extreme environmental perturbations are rare, but may have important evolutionary consequences. Responses to current perturbations may provide important information about the ability of living organisms to cope with similar conditions in the evolutionary past. Radioactive contamination from Chernobyl constitutes one such extreme perturbation, with significant but highly variable impact on local population density and mutation rates of different species of animals and plants. We explicitly tested the hypothesis that species with strong impacts of radiation on abundance were those with high rates of historical mutation accumulation as reflected by cytochrome b mitochondrial DNA base pair substitution rates during past environmental perturbations. Using a dataset of 32 species of birds we show higher historical mitochondrial substitution rates in species with the strongest negative impact of local levels of radiation on local population density. These effects were robust to different estimates of impact of radiation on abundance, weighting of estimates of abundance by sample size, statistical control for similarity in the response among species due to common phylogenetic descent, and effects of population size and longevity. Therefore, species that respond strongly to the impact of radiation from Chernobyl are also the species that in the past have been most susceptible to factors that have caused high substitution rates in mitochondrial DNA.

极端环境扰动虽属罕见，却可能对生物演化产生重要影响。对当前环境扰动的响应，可为揭示生物体在演化历史中应对同类胁迫的能力提供关键依据。切尔诺贝利核泄漏引发的放射性污染正是这类极端扰动之一，其对当地不同动植物物种的种群密度与突变率影响显著，但存在高度异质性。我们明确检验了一项假说：在过往环境扰动期间，受辐射对种群丰度产生强影响的物种，其历史突变积累速率往往更高——这一速率可通过线粒体DNA细胞色素b（cytochrome b mitochondrial DNA）的碱基替换速率来表征。通过对涵盖32种鸟类的数据集开展分析，我们发现：当地辐射水平对种群密度造成越强负面效应的鸟类类群，其历史线粒体替换速率越高。该结果在多项稳健性检验中均保持稳定，包括采用不同的辐射对种群丰度影响评估方法、以样本量对丰度评估结果进行加权、通过统计控制消除物种间因共同系统发育亲缘关系导致的响应相似性偏倚，以及控制种群大小与寿命的干扰效应。由此可见，对切尔诺贝利核辐射影响响应强烈的物种，同样是历史上最易受诱发线粒体DNA高替换速率因素影响的类群。