There’s a rather interesting article appearing today in New Scientists pertaining to desert people having evolved to be able to drink water poisoned with deadly arsenic without harm. Some of those people live in the South American deserts and it is now believed they evolved with an ability to detoxify arsenic laced water often found in desert regions.
About 7 kya settlers living in Chile’s Atacama desert were living in one of the planet’s driest non-polar deserts and many of their water sources had high levels of arsenic. Somehow people have survived in that and other desert areas drinking arsenic laced water.
Research shows that a single gene is responsible for this unique trait. In fact previous studies have also found similar mutations in the DNA of desert dwellers. Some scientists believe this to be an example of modern evolution in some humans and it might well be so. Another phenomena believed by some scientists to be yet another example of contemporary human evolution is lactose tolerance. It’s believe a mutation 7 kya also gave some humans the ability to digest milk and dairy products. Not all humans, however, are tolerant of lactose and many are in fact lactose intolerant. On average only about 35% of humans are lactose tolerant while the remaining 65% are not. As you can see MOST humans are lactose intolerant! It’s believe the mutation that brought about tolerance developed alongside dairy farming. So if you are lactose tolerant does that mean you come from dairy farmer stock 7 kya? Maybe 🙂
Arsenic at varied levels is a common poison found in desert water all over the world.