Apparently, if you suck face for too long, you can become part of that visage, fused forever. And by “you” I mean all the Demodex folliculorum skin mites that read this essay. It was news to me that our faces are like high-rise condos for microscopic skin mites which live in our hair follicles and suck out the yummy, gummy skin flakes that accumulate within. I guess they’re like remoras for people. As if that was not unsettling enough, these tiny critters haul themselves out of our greasy pores at night to crawl across our sleeping mugs and fornicate.

Unlike all other mite species, the male D. folliculorum has a penis in the middle of his back, toward the front, like a wee dorsal fin. The menacing score from the film “Jaws” would set the stage perfectly as a male emerges under a female mite in slow-motion (which happens to be their top speed) and does the mite-baby dance right under our nose. Literally, in this case. Outside of the unfortunate detail that you’re now aware of these facts, Demodex folliculorum generally do not cause us any harm. Although in rare instances people can develop an allergy to them, scientists think skin mites actually help us by keeping pores open.

But here’s the creepiest part: There’s good evidence to suggest D. folliculorum will eventually become a part of our faces. In an article published on June 21, 2022 in the journal Molecular Biology and Evolution,
authors G. Smith and A. Manzano-Marín et al tell the world that skin mites are in the process of merging their DNA with ours. Compared to that, the Vulcan mind-meld is a big yawn. If there was only one thing in the world you could eat and you found a place that served it for free, it’s logical that you might want to live there. Dead, sloughed-off skin cells from humans is the sole item on Demodex folliculorum’s menu. They cannot survive on cat dander, and dogs won’t do either.

Wikimedia Commons photo.

But while moving into a 24-7 eatery makes sense, becoming part of the establishment itself is downright weird. One feature of skin mites that makes this probable is that they have a bare-bones genome (but no actual bones). After a bazillion generations on people-faces (and to a lesser extent, chests), free of predators and competitors, and with food right outside their door, the cushy lifestyle of D. folliculorum has led it to strip away unneeded genetic material. In example, they come out only at night because somewhere along the line they dropped the genes which code for UV-protectant pigments. These guys are in the same boat as vampires in terms of exposure to sunlight.

Skin mites also went right to the bottom where mobility is concerned. Their eight legs, which are all clustered near the head, are operated by single-cell muscles. This makes me feel a lot better about my own scrawny pins. They also have fewer kinds of proteins than other similar species. Here is perhaps the strongest evidence pointing to a human-mite meld in the distant future: An organism like this has what’s called an incomplete life cycle.

It matures in discrete stages, molting or shedding its skin as it moves on to the next phase. Normally, there are more cells in each successive stage. However, our face-dwelling friends do it backwards. Not like Benjamin Button exactly, as the intermediate (nymph) phase is bigger than the larval stage. But adults have considerably fewer cells than nymphs. This means little to me, but to biologists it signals that D. folliculorum has taken the first evolutionary step toward becoming internal human symbionts.

Don’t fret, though. Researchers point to our long association with skin mites as evidence that they play a small but beneficial role in our lives. Mites clean our pores, which might otherwise become infected. Years ago, we didn’t know how vital a robust and diverse gut flora was to our mental health, as well as physical. Perhaps there are other benefits of skin mites yet to be discovered. There mite be.

The full journal article can be accessed here.

Paul Hetzler is a former Cornell Cooperative Extension educator. He washes his face a lot more after this revelation.

A big thanks to Laurent Dubois of Sainte-Cécile-de-Masham, QC for suggesting this topic.

Photo at top: Wikimedia Commons photo.