A team of scientists from the Max Planck Institute (Germany) has discovered a key gene for the evolution of the human cerebral cortex, which is nothing but the seat of the mind, since it is the area of the brain in charge of controlling emotions, language and conscious thought. This important gene that appeared after our evolutionary separation from chimpanzees but before Neanderthals, stars in the study published in the journal Science .
It is the gene called ARHGAP11B which, according to the new work, is only present in the human genome. The new results would explain the evolution of the human lineage with respect to the rest of primates. This specific gene is responsible for the formation of the brain folds, characteristic of human evolution .
“The gene was generated as the product of an incomplete duplication of a second ARHGAP11A gene , which occurred after the separation of the human and chimpanzee lineages during evolution,” says Marta Florio, co-author of the work, to Sinc.
To confirm these hypotheses, the scientists analyzed the role of this gene in the development of the neocortex and in the generation of neurons from progenitor cells in an experiment with mice. They inserted the ARHGAP11B gene into the embryonic brain of a mouse , whose brain is small, its neocortex completely smooth and has a very small number of stem cells, especially progenitors that “are key to the evolutionary expansion of the neocortex of species with large brains ”, clarifies Florio.
Insertion of the gene into the developing mouse brain caused the number of progenitor cells to increase and the neocortex began to wrinkle (as in humans): “At the end of embryonic development, the surface of the neocortex began to wrinkle already have folds on the outer surface of the brain, which was reminiscent of the ‘gyrencephalic’ brain of humans ”, reports Florio.
The results confirm that the ARHGAP11B gene would be the origin of our intelligent species . In this way we can finally differentiate humans and hominids from the oldest apes, evolutionarily speaking.
