Science & Technology

Desert people evolve to drink poisonous water

By T.K. Randall
February 25, 2017 ·  2 comments



The Atacama Desert offers very little drinkable water. Image Credit: CC BY-SA 3.0 XTSY The drinking water available to the people of South America's Quebrada Camarones region is a particularly nasty concoction containing one microgram per liter of arsenic - that's 100 times more than the safe limit recommended for human consumption by the World Health Organization.

Despite this however, the local people seem to be thriving. The reason for this, scientists believe, is because over thousands of years they have evolved the ability to consume it without ill-effect.

In a new study, Mario Apata and colleagues from the University of Chile in Santiago investigated the genes of 150 people who live in regions where the water contains deadly levels of the chemical.

They found that these individuals had more of a protective enzyme capable of metabolising arsenic in to something that is less toxic and can be more easily expelled by the body."Our data suggest that a high arsenic metabolization capacity has been selected as an adaptive mechanism in these populations in order to survive in an arsenic-laden environment," they wrote.

It appears that, in a relatively small amount of time, natural selection has resulted in an entire population capable of surviving on a water source that would be deadly to most people.

It is similar to lactose tolerance - something that emerged around 7,000 years ago due to a mutation which allowed adults to digest milk through continued production of the enzyme lactase.

Even to this day, only around 25-35% of the world's population are able to drink it.

Source: New Scientist | Comments (2)

Tags: Chile, Water, Poison