The Zoo We Bear

By Drs. David Niesel and Norbert Herzog, Medical Discovery News Bacteria and viruses live on and in us as part of our normal flora or microbiome. In fact, microbes outnumber our own cells by 10 to 100 to 1. But there are even more creatures that we share our lives with, parasites and vermin. That sounds disgusting, vermin? Really? Studies of these creatures are actually quite revealing about human evolution and migration. For example, all of us harbor a mite that lives in the hair follicles on our faces called Demodex folliculorum. They are tubular in shape with iddy biddy legs and live deep in our follicles. Somewhere between 23 - 100% of people are colonized with them and this infestation is only rarely associated with a disease. Scientists collected mites from the faces 70 people of different origins, most from the US. They sequenced mitochondrial DNA from these mites. Since these mites are only shared between sexual partners or close family members, they can help determine where people came from. People from different continents harbor different varieties of mites on their faces. The type of mites that people carry remain the same even long after they have traveled to another geographical region and even generations later. As ancient humans left Africa and moved to other areas of the earth and became isolated populations, mites co-evolved along with them. So the type of mite you carry can help to identify your origins. Another group of scientists are s...
Source: Science - The Huffington Post - Category: Science Source Type: news