Human Accelerated Regions (2013)

The unique features of human beings, especially our enhanced cognitive capabilities, are largely the result of specialized aspects of our genome.  Comparative genomics studies searching for human-specific elements have identified regions that are highly conserved across mammals including our closest relative the chimpanzee, but show accelerated mutation rates selectively in humans (known as Human Accelerated Regions or “HARs”). Several of these regions have been linked to neural development, potentially underlying such traits as the massive expansion of the neocortex.  Many questions remain regarding the potential functional significance of these HARs, and many challenges are posed in trying to establish function of human sequence variants using genetically tractable model organisms. This is unchartered territory and the research could help bring us one step closer in understanding what makes us human, and perhaps uncover insight into mutations that cause disease.