The extreme lifestyle of Haenyeo Diverso de Haenyeo shapes their genetics

Often compared to sirens in media relationships and popular culture, the famous South Korea Haenyeo (“Sea Women”) spend a large part of the day underwater, plunging without diving equipment to collect elmals, octopus, varech and other prized seafood. Admired both culturally and scientifically, they have plunged into the freezing waters of the island of Jeju for 503 this

Now, for the first time, A study has found both genetic adaptations and training effects that are unique to these women and could explain how the Haenyeo Resist intense physical stress that accompanies continuous diving. The results, published in Cell reports, zero in the specific genetic characteristics of Haenyeo which allow the bodies of these divers to more effectively control blood pressure, for example. Researchers hope that closer surveys in such genetic traits could shed light on future approaches to certain disorders or diseases of the general population.

“THE Haenyeo are really like superhumans, ”says Melissa A. IlardoMain author of the study and evolutionary geneticist at the University of Utah. “You can’t watch the Haenyeo Immerse yourself and do not think that these women have superpowers. »»

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It is easy to see the Haenyeo as enigmatic. For centuries, they obviously maintained their own culture and style. They display large junction sun visors and tattooed eyebrows, and their skin is tanned and altered by a life of wind and salt water. After Haenyeo Divers are aging beyond their diving years, they always stick near the sea and work along the shore, often attaching a cushion to their back to rest while they were going beyond Varech to dry. They kept their tradition afloat through the occupation of Japan in Japan in the Korean peninsula, massacres under dictatorships and incessant industrial development. And the new study suggests that there could even be a ring of scientific truth to the analogy of “superpower”.

“Given that (the Haenyeo) have this unique culture, a unique language – all these things that are so different – it seems obvious that there would be genetic differences, “says Ilardo.” But it was not something that had ever been studied. »»

Ilardo, who studies the genetics of medically resilient humans from the world Superhuman laboratoryhad Examined previously The physiology of a diving people called the bajau in Southeast Asia. His team found that the bajau had a very large spleen that could store additional oxygenated blood for long dives.

“If a group of divers had evolved to dive, then maybe others have done so,” explains Ilardo. THE Haenyeo– With their long history of diving – throws the crew of the superhuman laboratory as another population which could have developed advantages of diving.

“What is interesting in the study of the populations that have experienced in a particular environment for many generations is that if there has been selective pressure in this environment, you can watch their genomes and start with regions that seem to be essential for their survival,” explains Tatum SimonsonA geneticist at the University of California in San Diego, who was not involved in the new study. These essential genetic irregularities are “probably linked to certain aspects of physiology that have been beneficial over time in this environment”.

For the new study on HaenyeoThe superhuman laboratory has collaborated with physiologists from South Korea to simulate the effects of submersion on the divers themselves, compared to noHaenyeo Residents of Jeju and continental South Koreans. The participants lying on their stomachs with their heads on a bowl of cold water, periodically plunging their faces while the researchers measured how their reflexive submersion responses changed their heart rate and blood pressure.

The participants were all from the same country, but they showed striking differences in these changes. Ilardo thinks it could be the direct result of natural selection. For example, “sleep apnea – which is a bit like an involuntary dive into your sleep (in that it reduces the availability of oxygen) – increases the risk of hypertensive disorders during pregnancy,” she explains, adding that he can include preeclampsia (a complication of pregnancy which can dangerously increase blood pressure). THE Haenyeo are known to continue diving during pregnancy, she notes. “If the dive increases (a Haenyeo Diver) risk of preeclampsia, which could eliminate an entire generation, ”explains Ilardo.

But the Haenyeo are not known to have a particularly high risk of hypertensive pregnancy disorders, and they have obviously been born of many generations of babies. Ilardo’s research suggests that it is likely that a gene for better regulation of blood pressure has been transmitted over the years.

Interestingly, the team found that all Jeju residents – even those without Haenyeo Family member – had a similar genetic variation which removed an increase in reflexive blood pressure during diving. This suggests that the variation can propagate naturally throughout the island. It would also support the surprisingly low mortality rate of Jeju, which is around 24.3 per 100,000 for not only the Haenyeo but all Among the island residents – stronger than the rate of 25.7 per 100,000 in the continental city of Seoul and the level of the United States of 37 per 100,000.

But Ilardo notes that certain physiological differences, such as changes in heartbeat, were unique to the Haenyeo. During the experience of facial donations, Haenyeo The cardiac frequencies of participants slowed down 50% more, on average, compared to the residents of Jeju not divergers. This helps their bodies to manage the circulation of oxygen through their bodies during a long dive, letting them “spend this resource as frugally as possible”, explains Ilardo. She adds that this acquired trait could also develop in non -greedy people who are not on the island of Jeju. Although the study has not tested the participants’ cold tolerance, it is something that the superhuman laboratory plans to investigate in future work with the Haenyeo.

Researchers can learn from vital lessons on human evolution from these unique adaptations, says Ben TrumbleAn Arizona State University biologist who specializes in human biology and was not involved in the new study. Cataloging of lifestyle and genes of special populations such as the Haenyeo Could illuminate research on areas such as precision medicine, which requires a specialized understanding of how certain genetic variations result in physiological features, explains Trumble.

“We are absolutely authorized to plague natural selection” to approach health care, he said. “How natural selection solves a particular problem with a particular gene can give us clues to develop new drugs in order to deal with some of the problems that people have in our society today.”

Studies such as Ilardo are doing the “first step” to medical applications, says Trumble, although he and Simonson believe that real drugs that could emerge from this research will probably take more time to develop. In any case, says Ilardo, being able to determine the genetic cause behind the remarkable capacities of certain populations could offer remarkable solutions in medical genetics.

“I was just blown away by the way the Haenyeo) How strong they are and how they balance this with this kindness, this sensitivity and this femininity, “says Ilardo.” I think that focusing on what makes the population special and unique …, it brings a health objective instead of a concentration on the disease (to research on medical genetics). And it’s certainly a much more fun way to do science. »»