Opinion: The metal pollution that made history: how it affected the Neanderthals’ brains
A Silent Metal that Made an Evolutionary Difference
For millions of years, hominids lived with lead without knowing it. Volcanic dust, water, and contaminated food were a natural part of the prehistoric environment. However, recent research suggests that lead poisoning limited the cognitive and social capabilities of our closest relatives: the Neanderthals. The study, led by Alysson Muotri from the University of California in San Diego, along with scientists from Australia, the United States, France, China, and Brazil, analyzed 51 fossil teeth from different species of extinct hominids and apes.
The Gene that Changed the Fate of Language
The key point of the study is genetic. Researchers discovered that only Homo sapiens have a modern variant of the NOVA1 gene, responsible for regulating neuronal development and the brain’s response to contaminants such as lead. In experiments with brain organoids—mini-brains grown from stem cells—scientists compared the modern and archaic versions of the gene. When exposed to lead, language neurons degraded in the archaic model but remained stable in the modern one. The finding suggests that lead exposure may have rewired early human brains.
A Human “Superpower” against Lead
According to researchers, the acquisition of this genetic variant was a turning point. While lead affected the learning and communication abilities of Neanderthals, it favored the emergence of a more complex language, cultural transmission, and social cooperation in modern humans. The study proposes that modern humans not only survived due to physical adaptation but also because of their ability to think and communicate, a trait that lead could have limited in other hominids.
