The brain grew by coincidence

One of our chromosomes has undergone three changes that have provided us with a larger brain than almost any other animal - especially apes.

MUTATION RESULTS IN AN EXTRA GENE 1

In the genetic material of one of our early ancestors, the NOTCH2 gene was copied to another location on chromosome 1. The copy was not complete, so it had no function.

REPAIR ACTIVATES THE GENE 2

After we parted from the other apes, the new gene was repaired and suddenly had an important function.

THE GENE HAS COPIED ITSELF UP UNTIL NOW 3

Over the past 3-4 million years, the gene has been copied, leaving three almost identical genes in the NOTCH2NL gene complex, which only exists in humans.