Vega-Trejo Regina, Vila-Pouca Catarina, Mitchell David J, Kotrschal Alexander
Department of Zoology, Stockholm University, Svante Arrhenius väg 18B, 10691 Stockholm, Sweden.
Department of Zoology, Edward Grey Institute, University of Oxford, OX1 3SZ Oxford, UK.
Evol Ecol. 2022;36(6):1045-1059. doi: 10.1007/s10682-022-10191-8. Epub 2022 Jun 21.
Cognitive and sensory abilities are vital in affecting survival under predation risk, leading to selection on brain anatomy. However, how exactly predation and brain evolution are linked has not yet been resolved, as current empirical evidence is inconclusive. This may be due to predation pressure having different effects across life stages and/or due to confounding factors in ecological comparisons of predation pressure. Here, we used adult guppies () to experimentally test how direct predation during adulthood would impact the relative brain size and brain anatomy of surviving individuals to examine if predators selectively remove individuals with specific brain morphology. To this end, we compared fish surviving predation to control fish, which were exposed to visual and olfactory predator cues but could not be predated on. We found that predation impacted the relative size of female brains. However, this effect was dependent on body size, as larger female survivors showed relatively larger brains, while smaller survivors showed relatively smaller brains when compared to control females. We found no differences in male relative brain size between survivors and controls, nor for any specific relative brain region sizes for either sex. Our results corroborate the important, yet complex, role of predation as an important driver of variation in brain size.
认知和感官能力对于在被捕食风险下影响生存至关重要，从而导致对脑解剖结构的选择。然而，捕食与脑进化究竟是如何联系的尚未得到解决，因为目前的实证证据尚无定论。这可能是由于捕食压力在生命阶段中具有不同影响，和/或由于捕食压力生态比较中的混杂因素。在此，我们使用成年孔雀鱼（）进行实验，以测试成年期的直接捕食如何影响存活个体的相对脑大小和脑解剖结构，从而检验捕食者是否会选择性地去除具有特定脑形态的个体。为此，我们将捕食后存活的鱼与对照鱼进行比较，对照鱼暴露于视觉和嗅觉捕食者线索，但不会被捕食。我们发现捕食影响了雌性的相对脑大小。然而，这种影响取决于体型，因为与对照雌性相比，体型较大的雌性幸存者显示出相对较大的脑，而体型较小的幸存者显示出相对较小的脑。我们发现幸存者和对照之间雄性相对脑大小没有差异，两性的任何特定相对脑区大小也没有差异。我们的结果证实了捕食作为脑大小变异的重要驱动因素的重要但复杂的作用。
