The evolutionary success of our species may have hinged on minute changes to our brain biochemistry after we diverged from the lineage leading to Neanderthals and Denisovans about half a million years ago 

Two of these tiny changes that set modern humans apart from Neanderthals and Denisovans affect the stability and genetic expression of the enzyme adenylosuccinate lyase, or ADSL. This enzyme is involved in the biosynthesis of purine, one of the fundamental building blocks of DNA, RNA, and other important biomolecules. In a study to be published in PNAS, researchers from the Okinawa Institute of Science and Technology (OIST), Japan and the Max Plank Institute for Evolutionary Anthropology, Germany have discovered that these changes may play an important role in our behavior, contributing new pieces to the great puzzle of who we humans are and where we come from. “Through our study, we have gotten clues into the functional consequences of some of the molecular changes that set modern humans apart from our ancestors,” says first author Dr. Xiang-Chun Ju of the Human Evolutionary Genomics Unit at OIST.