University of São Paulo: Research reveals genetic mutations that gave rise to modern humans
In a study published in Scientific Reports , an international team of researchers from the University of Barcelona, Spain, in partnership with the European Institute of Oncology and the Universities of Vienna and Milan, carried out an approximation that mapped the origin of some genetic variations that characterize our species.
In the work, using a publicly available dataset—data that take advantage of Neanderthal and Denisovan genomes, both distant relatives of modern humans, to compile a genomic catalog of specific variations of Homo sapiens —the researchers made an estimate to evaluate the age of variants associated with signs of positive selection, such as tissue-specific changes and mutations related to the shape of the face and cerebellum and cerebellar formation.
According to Tábita Hünemeier, professor at the Department of Genetics and Evolutionary Biology at the Institute of Biosciences (IB) at USP, who did not participate in the study, there is an understanding that human history is not linear and that different branches of our evolutionary tree not only coexisted, as well as intersected, is fundamental to science. “We have this idea that Homo sapiens is the tip of an evolutionary ladder. It is like any other species that has gone through a very diverse history and evolved with other species to get here. Somehow, it adapted better and ended up surviving,” she explains.
A biologist specializing in human population genetics, Tábita highlights that the periods of coexistence between hominid species, with greater genetic changes, were the focus of the study. “The first peak is in the separation of Homo sapiens from other Homos . The second is when Sapiens are dispersed out of Africa. They [researchers] find these encephalization genes in a period between 300,500,000 years ago and, a little more recently, they found the Neanderthal and Denisovan integration variants in the last 100,000 years, when these two species had contact,” she highlights.
Based on the new discovery, it will be possible to deepen anthropological and genetic investigations to understand the many complexities of evolution, as it is still difficult to determine precisely when the genetic variants that distinguish us from other human species emerged. “It is an important knowledge construction. I think we are increasingly understanding how our species has diversified and differentiated itself”, concludes Tábita.