Researchers found people living high up in the mountains of Argentina have developed a unique adaptation that allows them to tolerate the toxic chemical arsenic.
The people of this region have been exposed to high levels of arsenic for thousands of years, the Oxford University Press reported. The arsenic is released from volcanic bedrock and seeps into groundwater.
"How could this population adapt to tolerate arsenic, a potent killer of such ill repute that it's often the overused plot-driver of many murder mysteries?" The researchers asked.
To answer this question, the researchers performed a genome wide survey from a group of 124 Andean women and screened them for their ability to metabolize arsenic by looking at urine levels of the contaminant. The study revealed a set of nucleotide variants in the gene AS3MT, which were seen at much lower frequencies in control participants from Columbia and Peru.
The researchers believe this change in variant frequency among the Andean population occurred between 7,000 and 10,000 years ago based on the discovery of a mummy with unusually high levels of arsenic in its hair.
The findings suggest the Andean people adapted to these dangerous environmental factors through increased frequencies in protective variants. These nucleotide variants were distributed across the globe, and were seen at the highest frequencies in "Peruvians, Native Americans, Eastern Asia and Vietnam."
The researchers believed the local adaptation was triggered as a result of the potentially fatal effects of arsenic, which is deadliest to children people in their reproductive prime.
The findings were published in a recent edition of the journal Molecular Biology and Evolution.
