【卫报】灵长类觅食水果可能是其大脑进化的关键丨第64期

A western lowland gorilla. According to the study, primates that eat fruit have about 25% more brain tissue than leaf-eaters of the same body weight.

一只来自西部低地的大猩猩。研究表明，同等体重下，以水果为食的灵长类动物脑组织比以叶类为食的灵长类动物的重25%。

Foraging for fruit may have driven the evolution of large brains in primates, according to research attempting to unpick the mystery of our cerebral heftiness .

一项试图解开大脑进化之谜的研究发现，觅食水果可能催化了灵长类动物大脑的进化。

• Forage：vi. 搜寻粮草；搜寻

• Cerebral：a. 大脑的，脑的

• Heftiness：n. 健壮、大量

The finding appears to be a blow to a long-held theory that humans and other primates evolved big brains largely as a result of social pressures, with extra brain power needed to navigate and engage in complex social interactions. Instead the researchers say it supports the view that the evolution of larger brains is driven by diet.

这一发现似乎颠覆了长久以来人们对大脑发展的认识。既往认为，人类和其他灵长类的大脑进化主要由社会压力导致，额外的脑力用以掌控和从事复杂的社会互动。与此相反，新研究结果表明，饮食对大脑的进化起促进作用。

• as a result of：ad. 因此，由于；作为……的结果

"All of these things are co-evolving: brains are getting bigger, sociality is becoming more complex, diet quality is becoming better, but it is maybe a shift in that focus on what might have been relatively more important, or more consistent throughout [primate] evolution," said Alex DeCasien, co-author of the research from New York University.

“万物都在持续不断地共同发展：脑容量增加，社会关系复杂化，饮食质量提升。但是这可能是因为在（灵长类）演化过程中，关注点的转变趋势为更重要或持久的方向的缘故。”来自纽约大学的亚历克斯·德卡西恩，本研究论文的合著者提到。

Writing in the journal Nature Ecology & Evolution, DeCasien and colleagues describe how they analysed the differences in brain size between more than 140 non-human primate species to unpick whether larger brains were linked to diet or to social factors. These factors included group size, mating habits and social system - for example, whether a species was solitary or lived in a system where males are surrounded by a harem of females.

在《自然生态与进化》一杂志中，德卡西恩和他的同事们阐述了他们如何分析了超过140多种非人类灵长类动物物种大脑体积的区别，揭示其到底与饮食还是与社会因素有关。这些社会因素包括群体规模，交配习惯及社会体系等，例如，一个物种的生活结构是独居亦或一雄多雌。

• Harem：n. 为一个雄性动物所控制的许多雌性动物

After taking into account factors such as body size and the position of species on the evolutionary tree, the team found no evidence that greater sociality is linked to bigger brain size.

在考虑了这些因素（体型与及物种在进化树的位置）后，该团队发现，并没有迹象表明更大范围的社会性与更大的大脑体积相关。

Instead, they found that big brains appear to be linked to diet. According to the study, primates that eat fruit have about 25% more brain tissue than leaf-eaters of the same body weight. Omnivores were also found to have larger brains than leaf-eaters, although there was no difference when compared to fruit eaters.

相反，他们发现，大脑的尺寸与饮食有关。根据该研究发现，食用水果的灵长类拥有比以相同体重以树叶为生的灵长类多25%的大脑组织。而杂食类动物的大脑也比叶类为食的灵长类大脑要大，尽管与食用水果的灵长类相比没有明显差别。

DeCasien says the results support the idea that fruit-eating provides more energy than leaf-eating, aiding brain growth. "[Fruit] is higher quality, it is more nutrient dense , it requires less digesting time, than the leaves," she said.

德卡西恩认为，这个结论支持水果提供的能量要大于叶类，有助于大脑生长的理念。“（水果）的质量叫叶片更高，营养更丰富，消化需要的时间更短。”她说道。

• Dense：a. 稠密的；浓厚的

• Digesting：a. 消化的；吸收的