Reengineering Life is a column from Future Human about the ways humans are using biology to reprogram our bodies and the world around us.
To study how the human brain evolved, scientists have relied on fossilized skulls from our ancient ancestors. These have given us clues about how we differ from our predecessors — that Neanderthal brains were more elongated than our modern ones, for instance — but they can tell only so much. Now, tiny blobs of lab-grown tissue that resemble Neanderthal brains may be able to help fill in some of the gaps.
Researchers at the University of California, San Diego, used stem cells to create miniature brains containing DNA from Neanderthals, our closest human relatives who died out around 40,000 years ago. The research revealed that a genetic variant harbored by Neanderthals led to striking changes in the organoids, suggesting the gene played a major role in the development of the modern human brain. The findings were published on February 12 in the journal Science.
No bigger than a pea, these so-called brain organoids could help scientists understand how our brains evolved to become so sophisticated. They could also shed light on how brain disorders like depression, anxiety, autism, and schizophrenia arose.
“Our hypothesis is that the sophistication of the human brain came with an evolutionary trade-off,” senior author Alysson Muotri, PhD, a neuroscientist at the University of California San Diego School of Medicine, tells Future Human. “The more sophisticated our brains, the higher the probability or the susceptibility for things to go wrong.”
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