- Joined
- Dec 2, 2013
- Messages
- 3,237
- Reaction score
- 2,159
- Location
- Florida
- Gender
- Male
- Political Leaning
- Libertarian - Left
Your Hair Mites Are So Loyal Their DNA Reflects Your Ancestry | Science | Smithsonian
Most people would probably prefer to forget that their eyebrows are also shaggy ecosystems, home to scores of microscopic hair mites. But a DNA analysis reveals that your mites are incredibly loyal to you—and that could help scientists trace ancient human migrations and perhaps find new ways to treat common skin ailments. Demodex folliculorum is a species of mite that lives in and around the hair follicles of humans and other mammals. Bowdoin College evolutionary geneticist Michael Palopoli and his colleagues sampled the DNA of these mites living on a diverse group of 70 human hosts. Sequencing the mites' mitochondrial DNA revealed different lineages that closely match the ancestral geography of their human hosts. One mite lineage is common among people of European ancestry, no matter where they live in the world now, and is persistent even after generations in new locations. Other mite lineages are more common among people of Asian, African or Latin American ancestry.
There are a few possible reasons for this unusual mite fidelity, says Palopoli. His group favors the co-called skin traits model: “There may be something about the skin of people from different geographic origins that may be selecting for mites from different mitochondrial lineages,” he explains. “But we don't know what it might be about the skin that may be selecting for one lineage of mites over another.” Following this line of inquiry could help researchers solve mysteries of how and why otherwise benign mites have been previously linked to skin disorders such as rosacea and blepharitis, or eyelid inflammation. “One logical question that these results raise is whether one of these different, diverging mitochondrial lineages of mites might tend to be more or less likely than another in causing skin disorders," says Palopoli. "Maybe a mite from one mitochondrial lineage is particularly likely to cause rosacea. That could be really important, but we just don't know at this point.”
Most people would probably prefer to forget that their eyebrows are also shaggy ecosystems, home to scores of microscopic hair mites. But a DNA analysis reveals that your mites are incredibly loyal to you—and that could help scientists trace ancient human migrations and perhaps find new ways to treat common skin ailments. Demodex folliculorum is a species of mite that lives in and around the hair follicles of humans and other mammals. Bowdoin College evolutionary geneticist Michael Palopoli and his colleagues sampled the DNA of these mites living on a diverse group of 70 human hosts. Sequencing the mites' mitochondrial DNA revealed different lineages that closely match the ancestral geography of their human hosts. One mite lineage is common among people of European ancestry, no matter where they live in the world now, and is persistent even after generations in new locations. Other mite lineages are more common among people of Asian, African or Latin American ancestry.
There are a few possible reasons for this unusual mite fidelity, says Palopoli. His group favors the co-called skin traits model: “There may be something about the skin of people from different geographic origins that may be selecting for mites from different mitochondrial lineages,” he explains. “But we don't know what it might be about the skin that may be selecting for one lineage of mites over another.” Following this line of inquiry could help researchers solve mysteries of how and why otherwise benign mites have been previously linked to skin disorders such as rosacea and blepharitis, or eyelid inflammation. “One logical question that these results raise is whether one of these different, diverging mitochondrial lineages of mites might tend to be more or less likely than another in causing skin disorders," says Palopoli. "Maybe a mite from one mitochondrial lineage is particularly likely to cause rosacea. That could be really important, but we just don't know at this point.”
