Data from: Large-brained frogs mature later and live longer

Brain sizes vary substantially across vertebrate taxa yet the evolution of brain size appears tightly linked to the evolution of life histories. For example, larger-brained species generally live longer than smaller-brained species. A larger brain requires more time to grow and develop at a cost of exceeded gestation period and delayed weaning age. The cost of slower development may be compensated by better homeostasis control and increased cognitive abilities, both of which should increase survival probabilities and hence lifespan. To date this relationship between lifespan and brain size seems well established in homoeothermic animals, especially in mammals. Whether this pattern occurs also in other clades of vertebrates remains enigmatic. Here, we undertake the first comparative test of the relationship between lifespan and brain size in an ectothermic vertebrate group, the anuran amphibians. After controlling for the effects of shared ancestry and body size, we find a positive correlation between brain mass, age at sexual maturation, and lifespan, across 40 species of frogs. Moreover, we also find that the ventral brain regions, including the olfactory bulbs, are larger in long-lived species. Our results indicate that the relationship between life history and brain evolution follows a general pattern across vertebrate clades.脊椎动物类群间脑容量差异显著，然而脑容量的演化似乎与生活史演化紧密相关。例如，脑容量较大的物种通常比脑容量较小的物种寿命更长。较大的脑需要更长的时间生长发育，代价为妊娠期延长与断奶年龄延迟。发育迟缓的成本或许可通过更优异的内稳态调控与更高的认知能力予以补偿，二者均可提升生存概率，进而延长寿命。截至目前，寿命与脑容量之间的这种关联在恒温动物（homoeothermic animals），尤其是哺乳动物中已得到充分证实。而该模式是否同样存在于其他脊椎动物类群中仍属未知。本研究首次在变温脊椎动物（ectothermic vertebrate）类群——无尾两栖动物（anuran amphibians）中，对寿命与脑容量的关联开展比较检验。在控制共祖效应与体型大小的影响后，我们在40种蛙类中发现脑质量、性成熟年龄与寿命之间存在正相关关系。此外，我们还发现长寿物种的脑腹侧区域（ventral brain regions），包括嗅球（olfactory bulbs），体积更大。本研究结果表明，生活史与脑演化之间的关联在脊椎动物各演化支中遵循通用模式。