Researchers say that our ancestors brain were not as big as the one we have now. Evolution is an important part of the life process and just like everything, our brains have also evolved. Human brain is thought to have expanded over time allowing us to improve our skills to survive and develop tools, complex science, physics, chemistry and more.
Researchers from Duke University conducted an analysis to explain how such evolution happened to our brain. Researchers have revealed that they have been able to zero in to the gene which is responsible for making the human brains bigger in comparison to other non-humans primates like chimpanzees.
Study’s co-author Gregory Wray said, “What we found is 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.”
The human DNA and chimpanzee DNA are 95% identical; the human brain is markedly different from that of the primates.
Human brains are much bigger and complex with higher number of neurons and dense connectivity which leads to better intellectual and emotional cognitions. To understand the cause behind these difference researchers started to research on genome portions of two species. During the course of the study researchers located a DNA section known as Junk DNA called human-accelerated regulatory enhanced (HARE5), which they believe is responsible for this major difference.
To further test this hypothesis, the researchers extracted chimpanzee and human DNA from these regions and inserted them into mice embryos. Researchers noted that putting the human version of the DNA increased the rapid division of stem cells leading to the development of more neurons. The Mice with the human version of the DNA had brains almost 12% larger before birth. The researchers wanted to know if bigger brains in mice will eventually lead to better brain function during adulthood. The study also revealed that the development period of humans and chimpanzees are almost identical.