Updated

Updated · ScienceAlert · Jun 24

Argentinian Andes Population Evolved Arsenic-Tolerance Gene After 7,000 Years of Exposure

Updated

Updated · ScienceAlert · Jun 24

Argentinian Andes Population Evolved Arsenic-Tolerance Gene After 7,000 Years of Exposure

Q: What hidden biological price do Andeans pay for their genetic ability to drink water laced with arsenic?

There is no clear evidence in the cited 2015 study that the arsenic-protective gene itself carries a separate, built-in biological trade-off. What the evidence does show is that the adaptation is only partial: Andeans with the AS3MT-linked variant can process arsenic more efficiently, but they are not immune to the damage from lifelong exposure. The likely “price” is the continuing burden of chronic arsenic toxicity. Research from the Andes and nearby arsenic-exposed regions links long-term exposure to higher risks of lung, bladder, skin and liver cancers, as well as cardiovascular disease, hypertension, respiratory illness, and metabolic disorders such as type 2 diabetes. Early-life exposure is especially concerning, with evidence of low birth weight, anemia, gestational diabetes, impaired lung function, and later-life cancer risk. There is also evidence that arsenic disrupts immune function and inflammation pathways, which may help explain persistent vulnerability to infection, skin disease, and some cancers even in populations that metabolize arsenic better than others. So the hidden price is not that the gene suddenly makes Andeans sick in some other way; it is that natural selection has reduced, not erased, the harm. Their bodies are better at detoxifying arsenic, but they still appear to pay with elevated long-term risks to the immune system, lungs, heart, metabolism, and cancer burden as long as the exposure continues. Clean water remains the real protection.

3 articles · Updated · ScienceAlert · Jun 24

DNA from 124 women in San Antonio de los Cobres showed a cluster of variants near the AS3MT gene linked to safer arsenic metabolism.
Those variants appear to reduce the buildup of toxic monomethylated arsenic and increase production of dimethylated arsenic, which the body excretes more easily in urine.
The finding fits decades of evidence from the high-altitude town, where drinking water carried about 200 micrograms of arsenic per liter until a 2012 filtration system—roughly 20 times the WHO guideline.
Researchers compared the Argentine samples with genome data from Peru and Colombia and found the protective variants were far more common locally, supporting natural selection from long-term exposure.
The study, published in Molecular Biology and Evolution, is presented as rare evidence that humans can genetically adapt to a toxic chemical in the environment.

Sources

ScienceAlert10h ago

Argentinian Andes Population Developed Genetic Adaptation to Arsenic

Yahoo! Voices10h ago

Humans in The Andes Seem to Have Evolved a Strange Genetic Ability

ScienceAlert10h ago

Humans in The Andes Appear to Have Evolved a Strange Genetic Ability : ScienceAlert

Could the genetic code of an arsenic-resistant population unlock a new defense against toxic water for the rest of us?

What hidden biological price do Andeans pay for their genetic ability to drink water laced with arsenic?

If human evolution can conquer arsenic in the Andes, why can’t technology solve the same water crisis in Afghanistan?

7,000 Years of Genetic Adaptation: How Andean Populations Evolved Resistance to Arsenic Poisoning

Overview

Researchers have discovered that people living in the Argentinian Andes, especially in San Antonio de los Cobres, have developed a unique genetic adaptation to survive chronic arsenic exposure. Over at least 7,000 years of drinking water with high arsenic levels, these populations evolved a specific variant of the AS3MT gene. This gene helps their bodies metabolize and excrete arsenic more efficiently, reducing its toxic effects. Such a rapid evolutionary response to a dangerous environmental stressor is rare in humans, making this a remarkable example of how people can adapt to harsh conditions through genetic changes.

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