Street Sally E, Navarrete Ana F, Reader Simon M, Laland Kevin N
Centre for Social Learning and Cognitive Evolution, School of Biology, University of St. Andrews, St. Andrews KY16 9AJ, United Kingdom;
Department of Anthropology, Durham University, Durham DH1 3LE, United Kingdom.
Proc Natl Acad Sci U S A. 2017 Jul 25;114(30):7908-7914. doi: 10.1073/pnas.1620734114. Epub 2017 Jul 24.
Explanations for primate brain expansion and the evolution of human cognition and culture remain contentious despite extensive research. While multiple comparative analyses have investigated variation in brain size across primate species, very few have addressed why primates vary in how much they use social learning. Here, we evaluate the hypothesis that the enhanced reliance on socially transmitted behavior observed in some primates has coevolved with enlarged brains, complex sociality, and extended lifespans. Using recently developed phylogenetic comparative methods we show that, across primate species, a measure of social learning proclivity increases with absolute and relative brain volume, longevity (specifically reproductive lifespan), and social group size, correcting for research effort. We also confirm relationships of absolute and relative brain volume with longevity (both juvenile period and reproductive lifespan) and social group size, although longevity is generally the stronger predictor. Relationships between social learning, brain volume, and longevity remain when controlling for maternal investment and are therefore not simply explained as a by-product of the generally slower life history expected for larger brained species. Our findings suggest that both brain expansion and high reliance on culturally transmitted behavior coevolved with sociality and extended lifespan in primates. This coevolution is consistent with the hypothesis that the evolution of large brains, sociality, and long lifespans has promoted reliance on culture, with reliance on culture in turn driving further increases in brain volume, cognitive abilities, and lifespans in some primate lineages.
尽管进行了广泛研究，但灵长类动物大脑扩张以及人类认知与文化进化的解释仍存在争议。虽然多项比较分析研究了灵长类物种间大脑大小的差异，但很少有研究探讨为何灵长类动物在社会学习的使用程度上存在差异。在此，我们评估这样一种假说：在一些灵长类动物中观察到的对社会传播行为的增强依赖，与大脑增大、复杂的社会性以及延长的寿命共同进化。使用最近开发的系统发育比较方法，我们表明，在灵长类物种中，一种社会学习倾向的度量随着绝对和相对脑容量、寿命（特别是生殖寿命）以及社会群体规模的增加而增加，并对研究工作量进行了校正。我们还证实了绝对和相对脑容量与寿命（幼年期和生殖寿命）以及社会群体规模之间的关系，尽管寿命通常是更强的预测指标。在控制母体投资后，社会学习、脑容量和寿命之间的关系依然存在，因此不能简单地将其解释为大脑较大物种通常预期的较慢生活史的副产品。我们的研究结果表明，大脑扩张和对文化传播行为的高度依赖在灵长类动物中与社会性和延长的寿命共同进化。这种共同进化与以下假说一致：大脑增大、社会性和长寿的进化促进了对文化的依赖，而对文化的依赖反过来又推动了一些灵长类谱系中脑容量、认知能力和寿命的进一步增加。
