I don't think the article was trying to claim that the population there is genetically different. I read the Karelia passage as arguing that people all over the

I don't think the article was trying to claim that the population there is genetically different. I read the Karelia passage as arguing that people all over the world have developed fantastically aggressive immune systems that will activate in response to gluten if not given a better target, such as the fecal born pathogens common in Karelian life.