DeCasien Alex R, Williams Scott A, Higham James P
Department of Anthropology, New York University, 25 Waverly Place, New York, New York 10003, USA.
New York Consortium in Evolutionary Primatology, New York, New York 10024, USA.
Nat Ecol Evol. 2017 Mar 27;1(5):112. doi: 10.1038/s41559-017-0112.
The social brain hypothesis posits that social complexity is the primary driver of primate cognitive complexity, and that social pressures ultimately led to the evolution of the large human brain. Although this idea has been supported by studies indicating positive relationships between relative brain and/or neocortex size and group size, reported effects of different social and mating systems are highly conflicting. Here, we use a much larger sample of primates, more recent phylogenies, and updated statistical techniques, to show that brain size is predicted by diet, rather than multiple measures of sociality, after controlling for body size and phylogeny. Specifically, frugivores exhibit larger brains than folivores. Our results call into question the current emphasis on social rather than ecological explanations for the evolution of large brains in primates and evoke a range of ecological and developmental hypotheses centred on frugivory, including spatial information storage, extractive foraging and overcoming metabolic constraints.
社会大脑假说认为，社会复杂性是灵长类动物认知复杂性的主要驱动力，并且社会压力最终导致了人类大脑的进化。尽管这一观点得到了一些研究的支持，这些研究表明相对脑容量和/或新皮层大小与群体大小之间存在正相关关系，但关于不同社会和交配系统的报道效应却存在高度冲突。在这里，我们使用了更大的灵长类动物样本、更新的系统发育树和改进的统计技术，以表明在控制了体型和系统发育后，大脑大小是由饮食预测的，而不是多种社会性指标。具体而言，食果动物的大脑比食叶动物的更大。我们的结果对当前关于灵长类动物大脑进化的社会而非生态解释的重点提出了质疑，并引发了一系列以食果性为中心的生态和发育假说，包括空间信息存储、提取性觅食和克服代谢限制。
