We All Have Rare Structural Variants

Professor Judith Rapoport explains that we all have rare structural variants, which may have been an evolutionary mechanism driving larger brain sizes,

It is certain that we all have structural variation, and in fact, if you look at the way the chromosome is and its spelling out in letters, most of it almost looks like stuttering – the same letters repeat over and over again. And there are even theories that repeat in the chromosome is part of evolution, so that one of the reasons it’s thought why brains got bigger was by just having twice as much of the same chromosome material just repeated seemed to advance, literally, size and size of certain organs, in a very simple-minded kind of way. It seems to be evolutionarily a very basic phenomenon: repeats in the chromosome.