Left to right: orangutan, gorilla, chimpanzee, human, and Neanderthal skulls overlaid with an illustration of the corresponding brainFIDDES ET AL.In the last few million years, the brains of humans and human ancestors have quickly evolved to be much bigger and more complex than their primate relatives. The genetic and molecular mechanisms that drove this expansion are still poorly understood, but two studies published today (May 31) in Cell describe a new gene family unique to humans that may have played a role in building bigger brains. The NOTCH2NL gene family is expressed during human cortical development and promotes neural progenitor cell renewal, which leads to more neurons.
We have an exceptional opportunity to find the changes that occurred in our ancestors’ DNA that made us human.
“We know very little about how human-specific genes . . . might impact brain evolution and this [work] provides some really important insights,” says Debra Silver, a neuroscientist at Duke University in North Carolina who did not participate in the studies. “Both studies have used complementary approaches to investigate Notch’s role in progenitors, and they’re seeing really similar outcomes.”
“Usually in biology, we tend to think that it’s the things that are highly conserved that are very important,” says a coauthor of one study, Pierre Vanderhaeghen, a developmental neurobiologist at the Université Libre de Bruxelles and Katholieke Universiteit Leuven in Belgium. “If we only look at ...
