Sagitov S, Mehlig B, Jagers P, Vatutin V
Mathematical Sciences, Chalmers and Gothenburg University, SE-41296 Gothenburg, Sweden.
Theor Popul Biol. 2013 Feb;83:145-54. doi: 10.1016/j.tpb.2012.09.002. Epub 2012 Sep 17.
Evolutionary branching is analysed in a stochastic, individual-based population model under mutation and selection. In such models, the common assumption is that individual reproduction and life career are characterised by values of a trait, and also by population sizes, and that mutations lead to small changes ϵ in trait value. Then, traditionally, the evolutionary dynamics is studied in the limit ϵ→0. In the present approach, small but non-negligible mutational steps are considered. By means of theoretical analysis in the limit of infinitely large populations, as well as computer simulations, we demonstrate how discrete mutational steps affect the patterns of evolutionary branching. We also argue that the average time to the first branching depends in a sensitive way on both mutational step size and population size.
在一个基于个体的随机种群模型中，对突变和选择下的进化分支进行了分析。在这类模型中，通常的假设是个体繁殖和生命历程由一个性状的值以及种群大小来表征，并且突变会导致性状值发生微小变化ϵ。传统上，进化动力学是在ϵ→0的极限情况下进行研究的。在本方法中，考虑了虽小但不可忽略的突变步骤。通过在无限大种群极限下的理论分析以及计算机模拟，我们展示了离散突变步骤如何影响进化分支模式。我们还认为首次分支的平均时间以一种敏感的方式依赖于突变步长和种群大小。
