In an experiment that could portend a real-life Planet of the Apes situation, scientists spliced human genes into the fetus of a monkey to substantially increase the size of the primate’s brain. And it worked.
Researchers from Germany’s Max Planck Institute of Molecular Cell Biology and Genetics in Germany and Japan’s Central Institute for Experimental Animals introduced a specifically human gene, ARHGAP11B, into the fetus of a common marmoset monkey, causing the enlargement of its brain’s neocortex. The scientists reported their findings in Science.
The neocortex is the newest part of the brain to evolve. It’s in the name—“neo” meaning new, and “cortex” meaning, well, the bark of a tree. This outer shell makes up more than 75 percent of the human brain and is responsible for many of the perks and quirks that make us uniquely human, including reasoning and complex language.