SLOW AND STEADY WINS THE BRAIN GAME

Small genetic changes separate modern humans from ancestral brain development.

Our closest relatives are Neanderthals (split from modern humans at least 500,000 years ago) and their Asian relatives the Denisovans (split from modern humans around 800,000 years ago). The differences between

Homo sapiens and these other groups are encoded in changes in amino acids, about 100 of which differ in modern humans. Published in Science

Advances, research from the Max Planck Institute for Evolutionary Anthropology investigated how six of these amino acids impact brain development, introducing them into mice. The six amino acid positions are identical in mice and Neanderthals.

“We found that three modern human amino acids … cause a longer metaphase, a phase where chromosomes are prepared for cell division,” says lead author, Felipe Morabermúdez. “This results in fewer errors when the chromosomes are distributed to the daughter cells of the neural stem cells, just like in modern humans.”