Department of Ecology, Evolution and Behavior, University of Minnesota, Minneapolis, Minnesota, 55455.
Department of Biology, University of Nevada-Reno, Reno, Nevada, 89557.
Evolution. 2020 Oct;74(10):2304-2319. doi: 10.1111/evo.14072. Epub 2020 Aug 15.
Nutrition has been hypothesized as an important constraint on brain evolution. However, it is unclear whether the availability of specific nutrients or the difficulty of locating high-quality diets limits brain evolution, especially over long periods of time. We found that dietary nutrient content predicted brain size across 42 species of butterflies. Brain size, relative to body size, was associated with the sodium and nitrogen content of a species' diet. There was no evidence that host plant apparency (measured by plant height) was related to brain evolution. The timing of diet shifts across species varied from 3.5 to 90 million years ago, but nutritional constraints did not lessen over time as species adapted to a diet. Although nutrition was linked to overall brain volume, there was no evidence that nutrition was related to the relative size of individual brain regions. Laboratory rearing experiments confirmed the underlying assumption of most comparative studies that the majority of interspecific trait variation stems from genetically based differences across species rather than developmental plasticity. This study highlights a novel role of sodium and nitrogen in brain evolution, which is additionally interesting given current anthropogenic change in the availability of these nutrients.
营养被认为是大脑进化的一个重要限制因素。然而，目前尚不清楚是特定营养素的可获得性还是寻找高质量饮食的难度限制了大脑进化，特别是在很长一段时间内。我们发现，饮食中的营养成分可以预测 42 种蝴蝶的大脑大小。相对于身体大小，大脑大小与物种饮食中的钠和氮含量有关。没有证据表明宿主植物的可见性（通过植物高度来衡量）与大脑进化有关。物种之间的饮食变化时间从 350 万年前到 9000 万年前不等，但随着物种适应饮食，营养限制并没有随着时间的推移而减轻。尽管营养与整体大脑体积有关，但没有证据表明营养与个体大脑区域的相对大小有关。实验室饲养实验证实了大多数比较研究的基本假设，即大多数种间特征变异源于物种间基于遗传的差异，而不是发育可塑性。这项研究强调了钠和氮在大脑进化中的新作用，考虑到当前这些营养物质的可获得性在人为因素影响下发生了变化，这一点尤其有趣。
