Crucial DNA That Makes Human Brains Bigger than Chimps Discovered
Scientists have identified the gene that makes human brains bigger than those of other non-human primates like Chimpanzees.
According to The Washington Post, human brains are markedly different from brains of other primates as they are multiple times bigger, comprising higher number of neurons with dense connectivity which brings about the intellectual and emotional cognition humans are known for. The difference exists despite humans and chimpanzee DNA being 95 identical.
To zero in on the genetic cause for this difference, scientists began looking at genome portions of the two species which vary. In the region earlier known has Junk DNA, Duke University researchers located a DNA stretch called human-accelerated regulatory enhanced or HARE5 which they believe causes the difference. To test their hypothesis they extracted Chimpanzee and Human DNA from these regions and inserted them into mice embryos.
The human version of DNA accelerated rapid division of stem calls causing development of more neurons. NPR reported that the mice with human version of the DNA had brains 12 percent larger before birth. Researchers now want to know if bigger brains in mice will translate into improved brain function during adulthood.
Gestation period for Humans and Chimpanzees is nearly the same. However chimpanzee brain development levels by the 22nd week.
"What we found is a piece of the genetic basis for why we have a bigger brain. It really shows in sharp relief just how complicated those changes must have been. This is probably only one piece -- a little piece," said the study's co-author Gregory Wray in a news release.
The findings were published in the journal Current Biology.
