If you thought gigantic pandas had it bad, spare a thought for the tiny parasitic mites that reside in the pores of the skin on our faces, which, according to a recent DNA analysis, may be headed for an evolutionary dead end.
Their ecosystem becoming so tightly synchronized with humans demonstrates that the species is transitioning from a parasite to a symbiont, a creature wholly dependent on another for survival.
More than ninety percent of us harbor 0.3mm long mites in the oily folds of our faces, with the majority residing in pores near our noses and eyelashes.
It is perhaps the closest link to another animal that most of us are unaware of.
Demodex follicular spends its entire existence in the hair follicles of the human epidermis. During the day, they feed on our oily skin secretions; at night, they leave the pore to find mates and new follicles in which to breed and lay eggs.
Delete the notion if it makes you want to wash your face. Mites have been on you since birth; they are transmitted from mother to child during breastfeeding and reside too deeply in the pores to be wiped away. In addition, we need them, adds Dr. Alejandra Perotti, co-author of the study from the University of Reading.
“We should adore them since they are the only animals that live their entire lives on our bodies, and we should value them because they keep our pores clean.”
Possibly not everyone would concur. Each of the mites’ four pairs of short legs has a pair of claws. Beyond that, a lengthy worm-like body can sometimes be observed extending from our hair follicles under a microscope.
This most recent study, published in the journal Molecular Biology and Evolution, demonstrates how very close their relationship has evolved with humans.
Researchers analyzed the mite genome and determined that it contains the fewest functional genes of any arthropod (insects, arachnids, and crustaceans).
The researchers conclude that the animals have become so dependent on their human host that their genome is “eroding” — being reduced to the bare minimum of genes required for survival.
They discovered that the gene in arthropods that normally regulates waking and sleeping has been lost. Instead, the organism detects variations in the skin’s melatonin levels. It rises when we sleep, signaling Demodex to rise, and falls when we awaken, signaling them to return to our oily pores for meals.
They’ve also lost the gene that protects their body from UV light; what’s the point of being nocturnal? Even their bodily structure is simple, as each leg is powered by a solitary muscle cell.
Their ecosystem becoming so closely synchronized with people indicates that the species is transitioning from an external parasite to an interior symbiont – an organism wholly dependent on our survival.
As their genetic variety decreases, and along with it, their capacity to leave their host and find new partners, they are also at risk of becoming extinct, either due to the extinction of humans or a drastic shift in their habitat.
It was formerly believed that Demodex caused common skin diseases, however, evidence suggests that in healthy people, Demodex assists avoid problems like acne by unclogging pores.
However, according to Dr. Perotti, it is not the only reason we should care about them:
We live in a world where biodiversity should be protected, and these are our very own animals.
