A breakthrough paleogenomic study published in Nature Genetics has identified a specific genetic variant in the remains of individuals who inhabited the Atacama Desert approximately 12,500 years ago. This variant provided essential resistance to selenium-induced hepatotoxicity, a condition caused by the high levels of selenium naturally occurring in the region's groundwater and soil. This finding represents one of the earliest known examples of human evolutionary adaptation to localized mineral toxicity in the Americas.
The research team, utilizing high-coverage whole-genome sequencing, discovered that this selection pressure likely occurred within a few generations of the population's arrival in the arid highlands. The study highlights the extreme plasticity of the human genome and the rapid pace of evolutionary selection when faced with lethal environmental stressors. These results provide a new window into the physiological challenges faced by the earliest Paleo-American pioneers as they navigated the diverse ecological niches of the Southern Andes.