Humans have never been alone. From birth, we have a certain creature in the pores of our face. The name is Demodex follicle. Recently, British scientists thoroughly studied these species with human faces as their home by DNA sequencing, and found that because they are too dependent on humans, they face an existential threat following continuous inbreeding.
My face is the warm home of little mites
Every night people go to bed following brushing their teeth, washing their faces, and applying lotion. But the little mites that live on our faces are just regarding to start their day.
These little face-home mites are officially called Demodex folliculorum. It is only 0.3 mm in length and lives near the hair follicles and sebaceous glands of the facial skin. The most common areas are the nose and eyelashes.
First off, yes, there are tiny mites on your face (90% chance, anyway).
These little critters, known as Demodex folliculorum, feast on the oil that oozes from your hair follicles. (Aren’t they cute?) pic.twitter.com/lGWoCCOW9D
— Doug Main (@Douglas_Main) June 22, 2022
▲ British scientists recently used gene sequencing to carefully study the mites on the human face: Demodex follicles.
Together for a lifetime, so romantic
We may never know that there are creatures that are so “close” to us, in fact, more than 90% of people have traces of their lives on their faces. After all, from the time we were born, they migrated from our mothers to our faces by drinking breast milk, and have been with us ever since.
Alejandra Perotti, associate professor of invertebrate biology at the University of Reading, UK, and co-author of the Demodex follicle study, said: “We have to take care of them because they live on us our whole life. We Take good care of them because they clean your pores and keep them from getting clogged.”
“We should be happy to have a little creature living with us. And they’re really cute,” Perotti added.
Do mites also have an existential crisis?
Perotti used acne cleaning products to collect Demodex hair follicle mites on the nose and forehead of the subjects, and regarding 40 Demodex follicles might be collected at a time. Her research shows that Demodex follicles are closely related to humans, but they also pose the greatest threat to their survival.
ResearchRecently published the scientific journal “Molecular Biology and Evolution” (Molecular Biology and Evolution), with comprehensive DNA sequencing to study Demodex hair follicles, revealing their miraculous life: mating, body structure and evolutionary trends.
The study found that of all arthropods, Demodex folliculus had the fewest functional genes. Therefore, the relationship between species and humans is moving from parasitism to symbiosis, and may eventually enter an evolutionary dead end, the study infers.
▲ More than 90% of people have Demodex follicles on their faces, but their only route of transmission is from mother to child. (Source:Pixabay）
Because I love you, change your genes
Perotti said: “We analyzed the genetic arrangement of Demodex follicles is very different from other similar organisms, which may be because they are too adapted to the hidden life of human pores, so they change their DNA, which also leads to their special body structure and behavior. ”
The researchers found that the genes responsible for regulating when arthropods are awake and when to sleep are no longer visible in the DNA of Demodex follicles, which also makes Demodex follicles extremely dependent on humans for sleep. Perotti explained: “After nightfall, when we are asleep, Demodex follicles visit the pores, and then they love and have babies in there.”
Humans automatically secrete melatonin at night. When the Demodex follicles living on the skin detect an increase in melatonin, they wake up and become active; on the contrary, when human melatonin decreases during the day, Demodex follicles Then go back to the pores and fall asleep.
The Demodex follicle mites are only active at night, and the study also found that they no longer have genes that protect them from UV damage.
on the way to extinction
Although mites have established intimate relationships with humans and mammals since regarding 200 million years ago, Demodex follicles are too dependent on humans, forming a mechanism that can only be passed from human mothers to children. That is to say, Demodex follicles will not leave the face to find a new mating partner. Even if humans frequently exchange towels to wipe their faces, their own Demodex follicles will not run onto each other’s faces.
Such inbreeding also gradually lost the genetic diversity of Demodex follicles, and the genetic differences of Demodex follicles became smaller and smaller following being passed down from generation to generation. When the gene pool no longer changes, it will eventually face extinction.
friendship across species
In this study, the researchers also eliminated the wrong inferences in the past, hoping to regain a little reputation for Demodex follicles.
Demodex follicles live for regarding 2 to 3 weeks. It has been theorized in the past that Demodex follicles do not have an anus and will store all their feces in the body, causing inflammation or acne problems in human skin when they die. But this time following analysis, the researchers found that was not the case: They had anus.
Co-author Henk Braig, a researcher at the School of Natural Sciences at Bangor University, UK, clarified: “Demodex follicle mites have been wrong for a long time. It is known from research that they have long been associated with human relationships, allowing them to develop parts that are good for humans, for example, it keeps our pores from clogging.”
Two British researchers hope the study will lead to a reassessment of the use of these creatures in human life. Demodex follicles are good for skin health. In fact, they coexist peacefully with humans and are good partners for symbiosis.
But can humans avoid Demodex follicles on their way to extinction? “I don’t think we can stop nature, and we shouldn’t do it,” Perotti said. “But maintaining healthy skin is enough for them to thrive.”
(This article is written by Earth Atlas Team Reprinted with permission; source of the first image:[[User:Alan R Walker (talk) 09:16, 28 January 2014 (UTC)]], CC BY-SA 3.0via Wikimedia Commons）
