As a species who think, solve problem, and develop culture it’s because of the evolution of larger brains in the last 3 million years. The brain has played a very important role in adapting and changing the environment. But the genetic changes behind the expansion that made us human have been elusive.
NOTCH2NL, a gene family identified by a team of researchers that appears to play an important role in human-specific cortex development. Also, it may have been a driving force in the evolution of our large brains. NOTCH2NL are exclusively found in humans and it delays the differentiation of cortical stem cells into neurons that results in production of more neurons across the course of development. The genes are heavily expressed in neural stem cells of human cerebral cortex, and are located on a part of genome implicated in neurodevelopmental disorders. David Haussler, co-senior author of one the papers and a bioinformatician at the University of California, Santa Cruz, and Howard Hughes Medical Institute says "Our brains got three times as big primarily through the expansion of certain functional areas of the cerebral cortex, and that has to be a fundamental substrate for us becoming human. There's really no more exciting scientific question that I can think of than discovering and decoding the mysterious genetic changes that made us who we are."
By: Shruti Anand