Ancient viruses played a role in the advanced development of our brains, study finds. This work examines the origins of myelin, an insulating fatty membrane that forms around nerves and allows electrical impulses to be delivered more quickly.
According to the authors, a genetic sequence acquired from retroviruses – viruses that invade their host's DNA – is crucial for myelin production. This code is found today in modern mammals, amphibians and fish, the researchers say. They concluded that the sequence appeared in the tree of life around the same time as jaws, that is, around 360 million years ago.