Everything we know about evolution tells us that humans have primate ancestors, and that the development of our complex brains is what allowed ancient humans to forge the path that we’re on today. Determining what changes in primate brains prompted our fork of the evolution tree to take shape is something scientists in China are tackling in a revolutionary — and scary — way.
A new study led by researchers at the Kunming Institute of Zoology combined human brain genes with modern macaque monkeys, creating transgenic specimens that demonstrate more advanced problem-solving skills than their unmodified brethren. If you think this sounds like the plot of a bad sci-fi movie, that’s because it does.
Geneticists have identified many genes which differ between humans and primates, but determining which of the genes may have led to changes in brain chemistry has proven incredibly challenging. Some genes are thought to be linked to advanced speech, while others appear to be associated with overall brain size.
As MIT Technology Review reports, the Chinese research team focused on a gene called MCPH1 which, when damaged, produces babies with smaller brains than is typical. Adding the human version of MCPH1 to monkey embryos resulted in 11 specimens, but six of them died before any tests could be performed.
The remaining five, which the scientists confirmed have multiple copies of the human gene, were tasked with completing memory tests and were subjected to MRI scans. Interestingly, the researchers noted that the monkey’s brains weren’t actually any larger than their unmodified peers, but they did perform better with short-term memory exercises.
Obviously there’s a whole heap of ethical concerns here, not least of which is whether or not scientists should even be tampering with the makeup of primate brains. The research has received plenty of criticism, and some fellow researchers have written about the dangers and ethical pitfalls of toying with complex brains in the name of science.
Nevertheless, the researchers involved in the brain modification study intend to continue their work and may begin experimenting with different human brain genes in the future.