A study at Cornell University, New York, answers a question that, like that of the chicken and the egg, divided the neuroscientist community: what came first in the evolution of the most intelligent animals, the development of large brains or the formation of specialized areas in different cognitive abilities? The results of the research, led by Jordan Moore and Timothy DeVoogd, tip the balance towards the first hypothesis.
His work consisted of measuring the total size of the brains and that of 30 areas associated with different behaviors of 58 songbirds, belonging to 20 families . In this way, they detected that the brain areas that controlled the emission of sounds were significantly larger in birds with more varied and complex songs.
And the same happened with another area, the one that controlled the movements of the mouth and face: its size was greater in birds with short and thick beaks that feed on seeds, since they need to perform sophisticated maneuvers to open them. In contrast, the insectivores , with long and thin beaks, presented the areas specialized in these smaller actions.
Although the gray mass of vertebrates differ in size, composition and performance, the evolution of the total size explains most of the differences between them, explain the researchers in the journal Proceedings of the Royal Society B. And once the species acquires a voluminous brain, then additional neural networks appear adapted to specific cognitive capacities, such as language in the case of humans .
Size is what matters most at first: Larger brains also have a more developed cortex , which is the center of operations for memory, attention span, consciousness, and thought.
