Data from: Effects of demographic stochasticity and life-history strategies on times and probabilities to fixation

How life-history strategies influence the evolution of populations is not well understood. Most existing models stem from the Wright-Fisher model which considers discrete generations and a fixed population size, thus not taking into account any potential consequences of overlapping generations and demographic stochasticity on allelic frequencies. We introduce an individual-based model in which both population size and genotypic frequencies at a single bi-allelic locus are emergent properties of the model. Demographic parameters can be defined so as to represent a large range of r and K life-history strategies in a stable environment, and appropriate fixed effective population sizes are calculated so as to compare our model to the Wright-Fisher diffusion. Our results indicate that models with fixed population size that stem from the Wright-Fisher diffusion cannot fully capture the consequences of demographic stochasticity on allele fixation in long-lived species with low reproductive rates. This discrepancy is accentuated in the presence of demo-genetic feedback. Furthermore, we predict that populations with K- life-histories should maintain lower genetic diversity than those with r- life-histories.生命史策略如何影响种群演化，这一科学问题目前尚未得到充分阐释。现有多数演化模型均源自Wright-Fisher模型（Wright-Fisher model），该模型假设世代离散且种群规模固定，因此未考虑世代重叠与种群统计随机性对等位基因频率的潜在影响。本研究提出一种基于个体的演化模型，其中种群规模与单双等位基因位点的基因型频率均为模型的涌现属性。我们可通过设定人口统计学参数，在稳定环境中复现大范围的r-选择与K-选择生命史策略，并计算合适的固定有效种群规模，以便将本模型与Wright-Fisher扩散模型进行对比。研究结果表明，源自Wright-Fisher扩散模型的固定种群规模模型，无法完整刻画低繁殖率长寿物种中，种群统计随机性对等位基因固定过程的影响。当存在人口统计-遗传反馈时，这种模型间的差异会进一步被放大。此外，我们预测：相较于采用r-选择生命史的种群，采用K-选择生命史的种群将维持更低水平的遗传多样性。