Parasites drove human genetic variation

Around 100,000 years ago modern humans began spreading out of Africa, where they learn to adapt to the different climates,different ways to find food, as well as a new way to fight off new pathogens.In this article, research has shown that certain pathogens, like parasites worms had the biggest part in driving the natural selection of humans. However, genetic adaptation also could have  made humans more susceptible to autoimmune diseases.

       The scientist removed one at a time the different variables from their model in order to figure out which of the variables would have the strongest impact on their model. “What we show is that all three factors are important, but the strongest factor is the pathogenic environment,” says Rasmus Nielsen, a computational biologist at Berkeley, and a co-author of the study.

       The parasitic worms seemed to be the most strongest factor in the natural selection force, more so than bacteria or viruses. According to Rasmus Nielsen it makes sense because bacteria and viruses can evolve very quickly and may have the ability to rapidly circumvent any genetic advantages gained by the humans.  On the other hand, something that evolves slowly like worms give the humans time to solidify their defenses.

       I think this article gives a good inside view of how our bodies learn to adapt to the changing enivorment around us, who knows what will comes next that will make us, humans, evolve again.

Parasitic worms such as Schistosoma mansonicaused more genetic diversity in humans than did climate, diet, bacteria or viruses.