Geneticists from the University of California have discovered a mutation in sections of human DNA that occurred about 1 million years ago. It was he who made a man smarter than a monkey. Results of the study published in the journal Science.
There are certain regions in the genome that have remained unchanged during evolution. It is found in all mammals, but changes have occurred in humans in these areas and within a short period of evolution.
These areas are called “Human Accelerated Zones, HAR”. The same team of scientists discovered these regions in the early 2000s when they compared the human and chimpanzee genomes. Scientists believe that at least some of these HARs may be responsible for unique qualities that distinguish humans from their closest relatives, such as chimpanzees and bonobos.
In the new study, the team found that the three-dimensional folding of human DNA in the nucleus is a critical factor at this crucial moment for our species.
“To understand how these changes happen, imagine a long DNA scarf from our last common ancestor, around which chimpanzees wore around our necks. Stripes of different colors stretch across its entire length. Now imagine someone trying to make exactly the same scarf with imperfections. Some stripes are narrower or wider, and the colors are “When you wrap the new scarf around your neck, the stripes on the second scarf will not line up with those of the first. Similarly, the main difference between human and chimpanzee DNA is structural in nature,” the authors explain.
Many genes in HARs are enhancers, meaning they increase the transcription of the gene associated with them. The authors wanted to know whether these structural changes affect the recruitment of certain genes. To do this, the group compared the genomes of 241 mammalian species using a neural network. They identified 312 HAR genes. About 30% of HARs were located in regions of DNA where structural variations cause the human genome to fold differently from other primates.
The team also found that regions containing HARs are rich in genes that distinguish humans from our closest relatives, chimpanzees. Many HARs are involved in embryonic development, particularly in the formation of neural pathways associated with intelligence. Therefore, it is they who may be responsible for making a person smarter than their “relatives”.
In the future, the team will continue their research.