Shafaqna English- Scientists have discovered that early humans were exposed to lead throughout their childhoods and this toxic metal may have unexpectedly driven the evolution of language capabilities in modern humans. Analysis of fossil teeth shows lead exposure dates back over two million years, challenging the assumption that led toxicity is solely a modern problem.
In a ground-breaking experiment, researchers grew miniature brain models with Neanderthal-like genes and found they reacted more severely to lead exposure than those with modern human genes. The toxic metal particularly damaged language-related brain circuits in the Neanderthal models, while modern human genetics showed greater resistance.
This suggests that lead exposure may have created evolutionary pressure that favored genetic variants protecting brain development. These same genetic differences might explain why modern humans eventually outcompeted Neanderthals and developed more complex language abilities.
Source: Southern Cross University