If you need one more thing to put on the list of things about your life that you can blame on your parents, then here’s one everyone can add: face mites. Yes, believe it or not, everyone has them, you can’t get rid of them, and you get them from your parents. Well, you also exchange them with anyone else you brush faces with, but here’s the good news: they are harmless.
So breathe a sigh of relief and read about what a fascinating article from the WIRED website tells us about these benign facial hitchhikers:
New research out today in the Proceedings of the National Academy of Sciences reveals four distinct lineages of the face mite Demodex folliculorum that correspond to different regions of the world. African faces have genetically distinct African mites, Asian faces have Asian mites, and so too do Europeans and Latin Americans have their own varieties. Even if your family moved to a different continent long ago, your forebears passed down their brand of mites to their children, who themselves passed them on down the line.
Looking even farther back, the research also hints at how face mites hitchhiked on early humans out of Africa, evolving along with them into lineages specialized for certain groups of people around the planet. It seems we’ve had face mites for a long, long while, passing them back and forth between our family members and love-ahs with a kiss—and a little bit of face-to-face skin contact.
Leading the research was entomologist Michelle Trautwein of the California Academy of Sciences, who with her colleagues scraped people’s faces—hey, there are worse ways to make a living—then analyzed the DNA of all the mites they’d gathered. “We found four major lineages,” says Trautwein, “and the first three lineages were restricted to people of African, Asian, and Latin American ancestry.”
The fourth lineage, the European variety, is a bit different. It’s not restricted—it shows up in the three other groups of peoples. But Europeans tend to have only European mites, not picking up the mites of African, Asian, or Latin American folks. (It should be noted that the study didn’t delve into the face mites of all the world’s peoples. The researchers didn’t test populations like Aboriginal Australians, for instance, so there may be still more lineages beyond the four.)
So what’s going on here? Well, ever since Homo sapiensradiated out of Africa, those four groups of people have evolved in their isolation in obvious ways, like developing darker or lighter skin color. But more subtly, all manner of microorganisms have evolved right alongside humans. And with different skin types come different environments for tiny critters like mites.
“Some [skin types] do show different levels of hydration, and different levels of oil production, and different density of glands,” Trautwein says. “All kinds of differences.” So African mites may have evolved with uniquely African skin, while on the other side of the globe Latin American mites evolved with Latin American skin. As for those European mites, which show up on faces around the world, their spread is probably a side effect of imperialism and globalization. When Europeans occupied new countries, from Brazil to the Philippines, they brought along their face mites.
The populations of different lineages on our skin, though, are by no means static. Kiss your grandma on the cheek and you could exchange mites. “If you do have multiple people in your family that you spend a lot of time being physically close to, if you have multiple romantic partners across your life, there’s all these different opportunities to be colonized,” says Trautwein. Because families tend to be more kissy with each other than strangers, their blends of mites may persist for generations. But it’s always a give and take, mites coming and going, as cheeks hit cheeks.
So just remember during this holiday season, you are not only exchanging gifts with your beloved family, but you are very likely also going to be exchanging face mites under the mistletoe… For more of the grossly fascinating details of these weird arachnids, see the excellent article on the WIRED web site.
Source: WIRED.com – “Your Face Is Covered in Mites, and It’s Your Parents’ Fault“
Featured Image Credit: USDA