A recent study in Science Advances reveals that our ancestors were exposed to lead nearly two million years ago. This finding could reshape how we view the evolution of our brains and language.
Researchers from the University of California, San Diego, and Southern Cross University studied 51 fossilized teeth from ancient humans, Neanderthals, and extinct apes like Gigantopithecus. They discovered lead in 73% of the samples dating from 100,000 to 1.8 million years ago, found across Africa, Asia, and Europe. Unlike modern pollution from industry, this lead came from nature — soil, volcanic dust, and mineral-rich water.
Lead is known to be harmful, especially to developing brains. Even slight exposure can hurt cognition and communication, essential skills for survival. The research raises questions about why early Homo sapiens thrived while Neanderthals did not.
One possible reason lies in a gene called NOVA1, which plays a key role in brain development and communication. Modern humans possess a slightly different version of this gene compared to Neanderthals, differing by just one base pair. The researchers tested this by growing tiny brain models in the lab using both human and ancient versions of NOVA1, then exposed them to lead.
The results were striking. The modern NOVA1 models showed resistance to lead’s harmful effects, while the ancient variant suffered disruptions in the FOXP2 gene, crucial for speech and language skills. This suggests that the human version of NOVA1 may have shielded our ancestors’ brains, promoting better communication.
Enhanced communication might have given Homo sapiens an advantage over Neanderthals. Better social skills could lead to stronger cooperation and cultural sharing, which would help our species adapt to changing environments and spread across the globe.
Despite these exciting findings, scientists note that more research is necessary. While the results present a compelling connection between environment, genetics, and evolution, they are based on experimental evidence rather than direct DNA from fossils.
Interestingly, a metal that posed a risk to our ancestors might have inadvertently pushed evolution toward a smarter, more adaptable species.
This research aligns with a broader trend in studies examining how ancient environmental factors shaped human evolution. For instance, a continuing analysis reveals how variations in climate have influenced human adaptability over the millennia. The journey of Homo sapiens has always been one of challenges, learning, and growth.
For more insights into prehistoric human evolution and environmental influences, you can check the original publication here.
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Gigantopithecus,Homo sapiens,Human evolution,Neanderthals
