According to a new study published in the journal Current Biology, a group of American researchers has located the portion of human DNA (deoxyribonucleic acid) that accounts for developing the size of human brains. Debra Silver, an assistant professor of molecular genetics & microbiology at the Duke University Medical School and study author said that this discovery is highly significant in comprehending the part that a section of DNA plays in differentiating the evolution of humans from other animals.
She added that their findings could be important to better understanding the parts that different portions of human DNA play in this change. The investigative team identified the human-accelerated regulatory enhancer (HARES) by inserting pieces of the human DNA into rodents.
The investigative team noted that there are 16 big differences in the genetic sequence between human beings and chimpanzees. This makes it very hard to determine which genetic sequence is responsible for the complexity and the growth of the brain.
Human brains are generally three times heavier than chimp brains. Human brains are also more intricate in terms of its interconnections. Mice have a totally different gene sequence. This permitted the group of researchers to separate the different purposes of different sequences when the human DNA was introduced.
The study demonstrated that rodent brains implanted with the DNA developed faster and grew larger than the untreated rodents. The researchers believe the DNA worked by controlling the quantity of neural stem cells created by the mouse embryo, eventually raising the number of neurons made in the brain.
Their experiments did raise some concerns as well. Ruth Faden, director of the Johns Hopkins Berman Institute of Bioethics stated: “The prospect of, sort of, tearing down the barriers between humans and other nonhuman species in ways that really threaten our sense of ourselves as special is disturbing. One can never say never, but I think it’s a pretty long-shot, far-fetched type concern.”
Gene That Makes Brains Bigger Discovered