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Source: Fox

It's not Planet of the Apes just yet, but monkey fetuses grew bigger brains when spliced with human genes

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Nov 23, 2020, 6:43 PM EST (Updated)

Apparently some scientists who didn’t watch Planet of the Apes recently spliced human genes into marmoset monkey fetuses, which caused their brains to grow exponentially and fold like a human’s. 

In a new study published in Science, researchers from Germany’s Max Planck Institute of Molecular Cell Biology and Genetics in Germany and Japan’s Central Institute for Experimental Animals detailed their experiments involving the human gene ARHGAP11B, which “is only found in humans,” and “triggers brain stem cells to form more stem cells, a prerequisite for a bigger brain,” according to a release.

So (un)naturally, they introduced the gene into no more than 100-day-old common marmoset monkey fetuses, which caused the neocortex to grow substantially.

Wildtype (normal) and ARHGAP11B-transgenic fetal (101 days) marmoset brains. Yellow lines, boundaries of cerebral cortex; white lines, developing cerebellum; arrowheads, folds. Scale bars, 1 mm.(Credit: Heide et al. / MPI-CBG)

The neocortex makes up the brain’s outer shell, and accounts for nearly 75% of its total size. It enables much of what makes humans human, first and foremost complex language and reasoning. It’s also the newest part of our brain, having tripled in size after our hominid cousins broke off from our primate ones. Though this expansion took place over the course of some three million years, that was apparently too fast for hominid craniums, which resulted in folding, and eventually our uniquely human wrinkled neocortex.

Or at least it was uniquely human, until these scientists started mussing around with ARHGAP11B. The expression of the gene was unique to hominids, and scientists have come to believe it could be one of the big reasons human ancestors got such a brain boost over the years. In fact, previous experimentation introducing ARHGAP11B in mice and rodents found similar brain growth. But this is the first time the gene has been spliced into a “non-human primate and with typical human levels of expression,” according to Popular Mechanics
Thanks to the success of the experiment, which basically confirmed their brain-boosting presumptions, scientists are now further convinced that ARHGAP11B played a key part in our evolution. Alas, as a result, they also had to come up with a new classification of what this Splice-like, human-monkey hybrid should be called. So they landed on the not-scary-at-all “transgenic non-human primates.”   

Sadly, but presumably in the name of trying to stave off the primate uprising (for now), researchers terminated the fetuses before they could grow up and become Caesar