Scientists may have found the tiny DNA switch that made us human

Scientists at UC San Diego have discovered a small but powerful section of DNA, called HAR123, that could help explain what makes the human brain so unique. Instead of being a gene, HAR123 acts like a “volume control” for brain development, guiding how brain cells form and in what proportions. The human version of HAR123 behaves differently from the chimpanzee version, possibly giving us greater flexibility in how we think and learn. This finding could also help researchers understand the roots of certain brain-related conditions, including autism.