If you want to be a true sex symbol, you better have a body 10 and less brain … at least if you are a wader. According to a recent study byCenter for Ecological Research and Forest Applications(CREAF), these birds do not choose their partners based on the size of their brains, which would undermine some claims about the evolution of the brain and the sexual selection of the pair.
Studies of this type are essential to understand both the present and future evolution of the different species. As Daniel Sol, co-author of the study published in the Journal of Evolutionary Biology, explained to the Scientific Information and News Service (SINC), “In this study we ask ourselves what role sexual selection plays in the evolution of the brain of a group of birds, the waders”.
And what was the surprise when they observed that in species in which the female mates with several males, the brains are smaller in relation to the body than those species that are monogamous or in which the male mates with several females.
These results contradict two widely held opinions. On the one hand, the idea that natural selection has played a very important role in the evolution of the brain, “because if so, polygynous species (in which the male mates with several females) would also have to present sexual dimorphism ( different sizes between female and male), but according to our analyzes, this is not the case ”, explains the researcher. And on the other hand it contradicts the idea that the care of the offspring requires more cognitive capacities and, therefore, bigger brains. “ANDIn this case, the females of the polygynous species would have to have larger brains than the males., since they are in charge of taking care of the offspring; but in reality males and females do not differ in the relative size of the brain ”explains the CREAF researcher again.
At the moment, no exclusive conclusions can be drawn regarding the development of the brain and the way of mating and caring for the offspring. As Daniel Sol affirms to SINC, “With current evidence, we cannot conclude that sexual selection has been a major force in brain evolution.”.
