Nitsch A, Lummaa V, Faurie C
Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK.
Institute for Advanced Study in Toulouse, Toulouse, France.
J Evol Biol. 2016 Oct;29(10):1986-1998. doi: 10.1111/jeb.12922. Epub 2016 Jul 14.
Understanding dispersal behaviour and its determinants is critical for studies on life-history maximizing strategies. Although many studies have investigated the causes of dispersal, few have focused on the importance of sibship, despite that sibling interactions are predicted to lead to intrafamilial differences in dispersal patterns. Using a large demographic data set from pre-industrial Finland (n = 9000), we tested whether the sex-specific probability of dispersal depended on the presence of same-sex or opposite-sex elder siblings who can both compete and cooperate in the family. Overall, following our predictions, the presence of same-sex elder siblings increased the probability of dispersal from natal population for both sexes, whereas the number of opposite-sex siblings had less influence. Among males, dispersal was strongly linked to access to land resources. Female dispersal was mainly associated with competition over availability of mates but likely mediated by competition over access to wealthy mates rather mate availability per se. Besides ecological constraints, sibling interactions are strongly linked with dispersal decisions and need to be better considered in the studies on the evolution of family dynamics and fitness maximizing strategies in humans and other species.
了解扩散行为及其决定因素对于研究生命史最大化策略至关重要。尽管许多研究调查了扩散的原因，但很少有研究关注同胞关系的重要性，尽管有预测称同胞间的互动会导致家庭内部扩散模式的差异。利用来自工业化前芬兰的大量人口数据集（n = 9000），我们测试了特定性别的扩散概率是否取决于同性或异性年长同胞的存在，这些年长同胞在家庭中既能竞争又能合作。总体而言，正如我们所预测的，同性年长同胞的存在增加了两性从出生群体扩散的概率，而异性同胞的数量影响较小。在男性中，扩散与获得土地资源密切相关。女性的扩散主要与配偶可得性的竞争有关，但可能是由对获得富配偶的竞争而非配偶本身的可得性所介导。除了生态限制外，同胞间的互动与扩散决策密切相关，在关于人类和其他物种家庭动态演变及适应性最大化策略的研究中需要更好地加以考虑。
