Data for: Transplant experiments demonstrate that larger brains are favored in high competition environments in Trinidadian killifish

The extent to which the evolution of a larger brain is adaptive remains controversial. Trinidadian killifish (Anablepsoides hartii) are found in sites that differ in predation intensity; fish that experience decreased predation and increased intraspecific competition exhibit larger brains. We evaluated the connection between brain size and fitness (survival and growth) when killifish are found in their native habitats and when fish are transplanted from sites with predators to high-competition sites that lack predators. Selection for a larger brain was absent within locally adapted populations. Conversely, there was a strong positive relationship between brain size and growth in transplanted but not resident fish in high-competition environments. We also observed significantly larger brain sizes in the transplanted fish that were recaptured at the end of the experiment versus those that were not. Our results provide experimental support that larger brains increase fitness and are favore...

大型脑的演化是否具备适应性这一问题，至今仍存在争议。特立尼达鳉（Anablepsoides hartii）分布于捕食压力存在差异的生境中：栖息于捕食压力降低、种内竞争加剧生境的该物种个体，脑部尺寸更大。我们分别在鳉的原生生境，以及将其从有捕食者的生境移植至无捕食者的高竞争生境的两种情境下，评估了脑部尺寸与适合度（fitness，即存活与生长）之间的关联。在本地适应的种群中，并未出现针对更大脑部的选择压力。与之相反，在高竞争环境中，移植个体的脑部尺寸与生长速率呈显著正相关，而本地种群则无此关联。我们还观察到，实验结束时被重新捕获的移植个体，其脑部尺寸显著高于未被捕获的个体。本研究结果为"更大的脑部可提升适合度，并受到选择青睐"提供了实验支持