Genetic changes affect human brain evolutionary expansion

Also relationship between genetic changes and brain diseases found

10/24/2019 | 5:58 PM

How come people have such a big brain? Neuroscientists from Vrije Universiteit Amsterdam show that genetic changes in recent human evolution - and the role of these genes in the brain - have been an important determining factor. The research was published today in Nature Communications.

The researchers provide insight into the genetic influence on the evolutionary expansion of the human brain. They also show that both the genes and brain regions involved in evolution also play an important role in brain diseases. This is an important new step in understanding where those diseases come from.

Genetic influence
Neuroscientist Martijn van den Heuvel and his colleagues compared our brain to that of our closest evolutionary family member - the chimpanzee - and discovered that people in particular have larger brain areas in the frontal, parietal and temporal cerebral cortex. These areas play an important role in human cognition. Yongbin Wei and colleagues then calculated that a small number of evolutionally important genes - with changes in recent human evolution - are strongly expressed in these areas. These genes may therefore have played an important role in the evolutionary growth of the human brain as it is today.

Relationship genes and brain diseases
With this data, the researchers then investigated the relationship between these evolutionally altered genes and cognitive abilities and brain diseases in the modern human population. They show that these genes are related to intelligence and social skills and, moreover, are related to the risk for human brain diseases such as schizophrenia and autism.