The evolution of multi-cellular animals has produced a conspicuous trend toward increased body size. This trend has introduced at least two novel problems: an expected elevated risk of somatic disorders, such as cancer, and declining evolvability due to generally reduced population size, lower reproduction rate and extended generation time. Low population size is widely recognized to explain the high mutation rates in animals by limiting the presumed universally negative selection acting on mutation rates. Here, we present evidence from stochastic modeling that the direction and strength of selection acting on mutation rates is highly dependent on the evolution of somatic maintenance, and thus longevity, which modulates the cost of somatic mutations. We argue that the impact of the evolution of longevity on mutation rates may have been critical in facilitating animal evolution.

中文翻译：

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体细胞维持影响突变率的演变

多细胞动物的进化产生了明显的趋向于增加体型的趋势。这种趋势至少带来了两个新问题：预期的诸如癌症之类的躯体疾病风险升高，以及由于总体上种群数量减少，繁殖率降低和生成时间延长而导致的进化能力下降。人们普遍认为，低种群数量可通过限制对突变率起作用的普遍公认的负选择来解释动物中的高突变率。在这里，我们从随机建模中获得证据，表明选择的方向和强度对突变率的影响高度依赖于体细胞维持的进化，因此寿命长短，从而调节了体细胞突变的成本。