Genetic Factors Behind Human Brain Uniqueness Unveiled

Recent research conducted by scientists at the University of California San Diego School of Medicine has provided new insights into what makes the human brain distinct from other species. The study, published in Science Advances, focuses on human-accelerated regions (HARs)—specific segments of our genome that have accumulated a high number of mutations during human evolution. These regions are believed to be pivotal in developing human-specific traits and are linked to neurodevelopmental conditions such as autism.

One particularly important HAR identified in the study is HAR123. Unlike typical genes, HAR123 functions as a molecular enhancer—an element that regulates the activity of genes during development. Specifically, HAR123 influences the development of neural progenitor cells, which are responsible for generating neurons and glial cells that comprise the brain. It also modulates the balance between these cell types, impacting overall brain architecture.

The researchers found that HAR123's role as an enhancer promotes cognitive flexibility, a crucial human trait that enables individuals to unlearn and adapt to new information. Importantly, the human version of HAR123 exhibits different molecular effects compared to the chimpanzee version, shedding light on the genetic basis of our advanced neural capabilities.

This discovery advances our understanding of the molecular mechanisms underlying human brain evolution and could provide insights into neurodevelopmental disorders. Further investigation is needed to fully elucidate HAR123’s functions and its potential role in human brain disorders. The study was led by Dr. Miles Wilkinson and Dr. Kun Tan, whose work helps unravel the genetic drivers behind human intelligence and brain complexity.