Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education), China West Normal University, Nanchong, Sichuan 637009, China.
Institute of Eco-Adaptation in Amphibians and Reptiles, China West Normal University, Nanchong, Sichuan 637009, China.
Evolution. 2018 May;72(5):1174-1183. doi: 10.1111/evo.13478. Epub 2018 Apr 24.
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 life span. To date, this relationship between life span 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 life span 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 size, age at sexual maturation, and life span 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.
脑量在脊椎动物类群中差异很大，但脑量的进化似乎与生活史的进化紧密相关。例如，大脑较大的物种通常比大脑较小的物种寿命更长。一个更大的大脑需要更多的时间来生长和发育，代价是延长了妊娠期和延迟了断奶年龄。较慢的发育速度可能会被更好的体内平衡控制和更高的认知能力所补偿，这两者都应该提高生存概率，从而延长寿命。迄今为止，这种寿命和脑量之间的关系在恒温动物中，尤其是在哺乳动物中似乎已经得到很好的证实。这种模式是否也存在于脊椎动物的其他类群中仍然是个谜。在这里，我们首次在变温脊椎动物类群——蛙类中，对寿命和脑量之间的关系进行了比较测试。在控制了共同祖先和体型的影响后，我们发现 40 种青蛙的脑量、性成熟年龄和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，包括嗅球，更大。我们的结果表明，生活史和大脑进化之间的关系在整个脊椎动物类群中遵循一个普遍的模式。
