Department of Ecology and Evolution, University of Lausanne, Biophore, 1015 Lausanne, Switzerland.
Department of Ecology and Evolution, University of Lausanne, Biophore, 1015 Lausanne, Switzerland.
J Theor Biol. 2023 Sep 21;573:111598. doi: 10.1016/j.jtbi.2023.111598. Epub 2023 Aug 19.
The cost of germline maintenance gives rise to a trade-off between lowering the deleterious mutation rate and investing in life history functions. Therefore, life history and the mutation rate coevolve, but this coevolution is not well understood. We develop a mathematical model to analyse the evolution of resource allocation traits, which simultaneously affect life history and the deleterious mutation rate. First, we show that the invasion fitness of such resource allocation traits can be approximated by the basic reproductive number of the least-loaded class; the expected lifetime production of offspring without deleterious mutations born to individuals without deleterious mutations. Second, we apply the model to investigate (i) the coevolution of reproductive effort and germline maintenance and (ii) the coevolution of age-at-maturity and germline maintenance. This analysis provides two resource allocation predictions when exposure to environmental mutagens is higher. First, selection favours higher allocation to germline maintenance, even if it comes at the expense of life history functions, and leads to a shift in allocation towards reproduction rather than survival. Second, life histories tend to be faster, characterised by individuals with shorter lifespans and smaller body sizes at maturity. Our results suggest that mutation accumulation via the cost of germline maintenance can be a major force shaping life-history traits.
种系维持的成本导致降低有害突变率和投资于生活史功能之间的权衡。因此，生活史和突变率共同进化，但这种共同进化还不太清楚。我们开发了一个数学模型来分析资源分配特征的进化，这些特征同时影响生活史和有害突变率。首先，我们表明，这种资源分配特征的入侵适合度可以用最少负载类的基本繁殖数来近似；没有有害突变的个体所生后代的预期无突变寿命产量。其次，我们应用该模型来研究（i）生殖努力和种系维持的共同进化，以及（ii）成熟年龄和种系维持的共同进化。当暴露于环境诱变剂的水平较高时，这种分析提供了两种资源分配预测。首先，选择有利于更高的种系维持分配，即使这是以牺牲生活史功能为代价的，并且导致分配向生殖而不是生存的转变。其次，生活史往往更快，表现为寿命较短和成熟时体型较小的个体。我们的结果表明，通过种系维持的成本积累的突变可以是塑造生活史特征的主要力量。
