Department of Mathematics, Western University, 1151 Richmond Street, London, Ontario, N6A 5B7, Canada.
Department of Mathematics, Western University, 1151 Richmond Street, London, Ontario, N6A 5B7, Canada.
Theor Popul Biol. 2024 Jun;157:1-13. doi: 10.1016/j.tpb.2024.02.007. Epub 2024 Feb 27.
Individuals delay natal dispersal for many reasons. There may be no place to disperse to; immediate dispersal or reproduction may be too costly; immediate dispersal may mean that the individual and their relatives miss the benefits of group living. Understanding the factors that lead to the evolution of delayed dispersal is important because delayed dispersal sets the stage for complex social groups and social behavior. Here, we study the evolution of delayed dispersal when the quality of the local environment is improved by greater numbers of individuals (e.g., safety in numbers). We assume that individuals who delay natal dispersal also expect to delay personal reproduction. In addition, we assume that improved environmental quality benefits manifest as changes to fecundity and survival. We are interested in how do the changes in these life-history features affect delayed dispersal. We use a model that ties evolution to population dynamics. We also aim to understand the relationship between levels of delayed dispersal and the probability of establishing as an independent breeder (a population-level feature) in response to changes in life-history details. Our model emphasizes kin selection and considers a sexual organism, which allows us to study parent-offspring conflict over delayed dispersal. At evolutionary equilibrium, fecundity and survival benefits of group size or quality promote higher levels of delayed dispersal over a larger set of life histories with one exception. The exception is for benefits of increased group size or quality reaped by the individuals who delay dispersal. There, the increased benefit does not change the life histories supporting delay dispersal. Next, in contrast to previous predictions, we find that a low probability of establishing in a new location is not always associated with a higher incidence of delayed dispersal. Finally, we find that increased personal benefits of delayed dispersal exacerbate the conflict between parents and their offspring. We discuss our findings in relation to previous theoretical and empirical work, especially work related to cooperative breeding.
个体出于多种原因而延迟生育扩散。可能没有地方可以扩散；立即扩散或繁殖可能代价太高；立即扩散可能意味着个体及其亲属错过了群体生活的好处。了解导致延迟扩散进化的因素很重要，因为延迟扩散为复杂的社会群体和社会行为奠定了基础。在这里，我们研究了当地环境质量因个体数量增加而得到改善（例如，群体中更安全）时，延迟生育扩散的进化。我们假设，延迟生育扩散的个体也期望延迟个人繁殖。此外，我们假设环境质量的改善体现在繁殖力和存活率的变化上。我们感兴趣的是这些生活史特征的变化如何影响延迟扩散。我们使用将进化与种群动态联系起来的模型。我们还旨在了解延迟扩散水平与独立繁殖者建立的概率（种群水平特征）之间的关系，以响应生活史细节的变化。我们的模型强调了亲缘选择，并考虑了一个有性生物，这使我们能够研究亲子冲突对延迟扩散的影响。在进化平衡时，群体规模或质量的繁殖力和存活率的好处促进了更高水平的延迟扩散，这在一系列具有一个例外的生活史中更为明显。例外情况是个体延迟扩散所获得的群体规模或质量增加的好处。在这种情况下，增加的好处不会改变支持延迟扩散的生活史。其次，与之前的预测相反，我们发现，在新地点建立的可能性较低并不总是与延迟扩散的发生率较高相关。最后，我们发现，延迟扩散的个人利益增加会加剧父母与其后代之间的冲突。我们根据之前的理论和经验工作，特别是与合作繁殖有关的工作，讨论了我们的发现。
