In a new leading and controversial experiment, Chinese scientists said they tried to narrow the gap between the intelligence of humans and monkeys, by implanting human brain cells in monkeys' brains. "That's millions of individual DNA bases differing between humans and monkeys", he said.
The gene is involved in a process known as neoteny - the delaying or slowing of the development of an organism.
MCPH1 is expressed during fetal brain development, mutations can lead to microcephaly. Each monkey's brain also developed over an extended period of time, which was similar to the development of human brains.
According to the researchers, the experiments represent the first attempt to study the genetic basis of human brain origin using transgenic monkeys.
For others, the work provokes a profoundly moral and visceral uneasiness. Now we have created this animal which is different than it is supposed to be. Critics believe that transgenic experiments on monkeys and apes puts us on a slippery slope where it becomes hard to draw the line of what is acceptable and what is not. I don't think that is a good direction. "Styner goes on to say ".not looking forward to more evolution research on transgenic monkeys.
James Sikela, a geneticist and professor in the Department of Pharmacology at the University of Colorado, Denver, said that experimenting on transgenic monkeys to understand human evolution is a "classic slippery slope ... and a very risky road to take". Babies with damaged microcephalin are said to be born with tiny heads. "If you're actually interested in studying the cognitive complexity of these animals, you're not going to get a good representation of that by raising them in labs, because they can't develop the kind of cognitive and social skills they would in their normal environment".
One of the key differences between human and nonhuman primates is that humans require more time to shape neuronal networks during development that elongates childhood; these transgenic monkey models are reported to be practical and to a large extent able to mimic the human specific status. Multiple genes and their interactions affect the vast majority of traits. But, the monkey did not possess bigger brains than the control group.
A Rhesus macaque, part of the 11 rescued monkeys from research laboratories, looks on from the quarantine room of the future animal shelter "La Taniere", in Nogent-le-Phaye near Chartres March 13, 2019.
One of the lead authors, Bing Su, told MIT that he's testing other genes involved in brain evolution, including one dubbed the "humanity switch" for its presumed role in human intelligence. "After all, the 2011 movie, 'Rise of the Planet of the Apes", began with a monkey being genetically modified for research into Alzheimer's disease. In November a Chinese scientist claimed he had created the world's first gene-edited babies, sparking an worldwide outcry.
"The genome of rhesus monkeys differs from ours by a few per cent".
Martin Styner of the University of North Carolina who's role in this experiment was limited to training students how to extract brain volume from MRI images says "There are a bunch of aspects of this study that you could not do in the U.S., it raised issues about the type of research and whether the animals were properly cared for." .