Department of Biology, University of Turku, Turku, Finland.
Institute for Advanced Study in Toulouse, Université Toulouse 1 Capitole 1, Esplanade de l'Université, 31080, Cedex 6, Toulouse, France.
Sci Rep. 2023 May 9;13(1):7539. doi: 10.1038/s41598-023-33700-3.
Determining how sibling interactions alter the fitness outcomes of dispersal is pivotal for the understanding of family living, but such studies are currently scarce. Using a large demographic dataset on pre-industrial humans from Finland, we studied dispersal consequences on different indicators of lifetime reproductive success according to sex-specific birth rank (a strong determinant of dispersal in our population). Contrary to the predictions of the leading hypotheses, we found no support for differential fitness benefits of dispersal for either males or females undergoing low vs. high sibling competition. Our results are inconsistent with both hypotheses that family members could have different fitness maximizing strategies depending on birth rank, and that dispersal could be mainly driven by indirect fitness benefits for philopatric family members. Our study stresses the need for studying the relative outcomes of dispersal at the family level in order to understand the evolution of family living and dispersal behaviour.
确定兄弟姐妹间的相互作用如何改变扩散的适应结果对于理解家庭生活至关重要，但此类研究目前还很少。我们使用来自芬兰的工业化前人类的大型人口数据集，根据性别特异性出生顺序（我们人群中扩散的一个重要决定因素）研究了扩散对不同终身生殖成功指标的影响。与主要假设的预测相反，我们没有发现支持男性或女性在经历低与高兄弟姐妹竞争时，扩散对适应性益处的差异支持。我们的研究结果与以下两种假设均不一致，即家庭成员可能根据出生顺序具有不同的最大化适应性策略，并且扩散可能主要是由对亲代家庭成员的间接适应性益处驱动的。我们的研究强调了在家庭层面上研究扩散的相对结果的必要性，以便理解家庭生活和扩散行为的进化。
