Scientists at the Kunming Institute of Zoology and the Chinese Academy of Sciences worked with US researchers at the University of North Carolina to insert human versions of MCPH1 into the brains of 11 rhesus monkeys. The gene is believed to help develop the human brain and the results, which were published last month in Beijing-based journal National Science Review, showed the brains did perform better in short-term memory tests and their reaction times were quicker than wild monkeys. But the tests have raised ethical concerns as only five of the monkeys survived and they did not grow bigger brains.
Jacqueline Glover, a University of Colorado bioethicist, compared the study to dystopian sci-fi film Planet of the Apes.
She said to MIT Technology Review: “To humanise them is to cause harm.
“Where would they live and what would they do?
“Do not create a being that can’t have a meaningful life in any context.”
Larry Baum, a researcher at Hong Kong University’s Centre for Genomic Sciences, was not convinced by this comparison though.
He said: “The genome of rhesus monkeys differs from ours by a few percent.
“That’s millions of individual DNA bases differing between humans and monkeys.
“This study changed a few of those in just one of about 20,000 genes.
“You can decide for yourself whether there is anything to worry about.”
Mr Baum added the study showed “slower maturity of brain cells might be a factor in improving intelligence during human evolution”.
The authors of the journal wrote: “Our findings demonstrated that transgenic nonhuman primates (excluding ape species) have the potential to provide important – and potentially unique – insights into basic questions of what actually makes humans unique.”