Andean Arsenic Adaptation: A Genetic Shield Against Toxic Groundwater

DNA analysis of 124 women from the high-arsenic town San Antonio de los Cobres shows variants near the AS3MT gene that help metabolize arsenic more safely, producing excretable forms and fewer toxic intermediates. The pattern suggests long-term arsenic exposure has driven genetic adaptation in Andean populations, with similar signals in other Andean groups and implications for how humans adapt to environmental toxins (published in Molecular Biology and Evolution).