Researchers from Kunming Institute of Zoology and the University of North Carolina have successfully edited a human gene, microcephalin (MCPH1) into rhesus monkeys. MCPH1 is linked to brain size, according to this study. The monkeys exposed to this gene experienced what is known as neoteny in humans; to put simply, a slower development process to further develop the brain. On the molecular and microscopic levels, several things were visible to the researchers such as expression delay of neurons, altered cell differentiation, differentiation in synaptic signaling, etc. The only thing the scientists could record that wasn't microscopic was the monkeys expressing better short-term memory and shorter reaction time when compared with their wild type brothers and sisters.
While this study can help us to better understand how certain genes work for the human brain, it also feels like it's opening a door to a science-fiction future. One of the researchers that was a part of this team has even chastised this experiment. Is it ethical to modify the genetics of primates? It could be a very slippery slope to take, and could possibly open the door for a wide variety of issues.