Evolution In Humans!

[Moontanman]

A new study has identified the gene involved in a mutation that allows humans to tolerate high levels of arsenic in Andean villagers exposed for thousands of years to very high arsenic levels.
 
 http://www.the-scientist.com/?articles.view/articleNo/43019/title/Adapting-to-Arsenic/
 
By Ashley P. Taylor | June 1, 2015
 

 

I[/size]n parts of Argentina, people have been drinking poison—arsenic, to be specific—for thousands of years. The river running through the Andean village of San Antonio de los Cobres (SAC) has arsenic levels up to 80 times the safe limit established by the World Health Organization (WHO); it seeps into the groundwater from volcanic bedrock. Arsenic levels in the region’s tap water were as high as 20 times the WHO’s limit before 2012, when a filtration system was installed. The villagers are descended from indigenous Atacameño people who have lived and drunk the water in northern Argentina for as long as 11,000 years. Since 1994, Swedish biologist Karin Broberg, of Stockholm’s Karolinska Institute, and colleagues at Uppsala and Lund Universities have been trying to figure out how generations of SAC’s now nearly 6,000 residents have been able to survive this chronic arsenic exposure.

[CraigD]

Neat!

 

Underlying the story of Karin Broberg and her colleagues discovering the role of the AS3MT gene in metabolizing arsenic, and the correlation of high arsenic tolerance alleles of it in the population of people living in places with heavily arsenic-tainted water, though is a chilling implication about what a population selecting for these alleles means in terms of everyday human experience. Over the thousands of years that people have been living in San Antonio de los Cobres, genetically selecting for arsenic tolerance means that significant numbers of people born without the alleles died of arsenic poisoning before they grew old enough to have children. People moving to SAC would have found themselves sicker than long-time residents, and their children mysteriously cursed.

 

Nature is unsentimental.