The all-female free divers of Jeju Island have a 'superpower' in their genes

A South Korean female free diver jumps into nan oversea from a vessel disconnected nan seashore of Jeju Island connected Jan. 15, 2022. New investigation has recovered that these women, known arsenic Haenyeo, person circumstantial familial adaptations connected to acold tolerance and humor pressure. SeongJoon Cho/Bloomberg via Getty Images hide caption

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SeongJoon Cho/Bloomberg via Getty Images

A mates of years ago, Melissa Ilardo recovered herself aboard a motorboat traversing nan water astir Jeju Island, which sits immoderate 50 aliases 60 miles disconnected nan seashore of South Korea. Before nan alloy had moreover travel to a stop, an older female successful a wetsuit, fins and a disguise stepped into nan water. Two others followed her.

These women, whose plunge Ilardo captured connected video, beryllium to a agelong statement of female free divers connected Jeju Island called nan Haenyeo.

They swam off, each pinch a nett container successful tow, to cod seafood to eat and sell. "Things for illustration abalone, oversea urchins … seaweeds sometimes," says Ilardo, an evolutionary geneticist astatine nan University of Utah. The Haenyeo routinely dive successful waters that she says are 50 degrees Fahrenheit astatine nan surface, astatine best.

"One of nan first times I was there," Ilardo recalls, "it was snowing. They said arsenic agelong arsenic there's not a consequence that they're going to beryllium blown distant to sea, past they still spell retired successful nan water, nary matter really acold it is."

The women commencement diving arsenic girls and proceed good into aged age, crossed each of life's milestones. "They dive passim their full pregnancy," says Diana Aguilar-Gómez, a organization geneticist astatine UCLA. "They opportunity they conscionable dive until fundamentally earlier they springiness birth" and are backmost successful nan h2o a fewer days later.

Ilardo wanted to cognize really nan Haenyeo are tin of enduring specified an utmost lifestyle, she says: "How improvement mightiness person shaped nan Haenyeo to beryllium amended divers, to dive much safely, to dive for longer."

In a study published successful Cell Reports, Ilardo, Aguilar-Gómez and their colleagues uncover nan adaptations that make nan Haenyeo's superpower possible. It's a operation of physiological and familial changes, immoderate of which look to person had an effect connected nan full organization of Jeju Island.

A "silly" research pinch clear results

Ilardo decided to comparison nan Haenyeo to different aged women connected Jeju Island who aren't divers but person a akin familial background, and to still others off-island who aren't related. There were astir 30 successful each group.

A Haenyeo diver swims to drawback turban shells and abalones connected Nov. 6, 2015. Chung Sung-Jun/Getty Images hide caption

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Chung Sung-Jun/Getty Images

There was 1 problem: "You can't return 70-year-old women who person ne'er been diving and propulsion them successful nan unfastened ocean," says Ilardo.

Fortunately, there's a workaround. It's called a simulated dive. "You clasp your activity and put your look successful a vessel afloat of acold water," says Ilardo, "and your assemblage responds arsenic if you're diving. Your bosom complaint will driblet measurably."

The Haenyeo recovered nan research a small silly. "They said getting successful nan ocean, being underwater, that's diving. Whatever this is, this isn't diving," recalls Ilardo. "But they still held their activity agelong capable that we were capable to elicit a response."

That consequence was significant: The Haenyeo bosom complaint fell by astir 50% much than their non-diving peers. "We had 1 diver whose bosom complaint dropped complete 40 thumps per infinitesimal successful 15 seconds," says Ilardo.

She concludes that this is classical physiological adaptation. That's because nan cohort of different women from Jeju — nan non-divers pinch akin familial constitution — didn't acquisition nan aforesaid driblet successful bosom rate. The quality betwixt nan 2 groups is owed to a life of diving experience.

Pushing nan assemblage to its limits

Next, nan researchers took saliva samples to look for familial differences betwixt nan different groups. Everyone from Jeju — some nan Haenyeo and nan non-divers — had fundamentally nan aforesaid genes, meaning that nan group of this land look to person been genetically sculpted by generations of divers.

"What this suggests is that everybody successful Jeju has an arsenic apt chance of being a descendant of a diver," says Ilardo.

Two genes stood retired successful nan analysis. The first 1 seems to beryllium related to acold tolerance. "Maybe that protects them from hypothermia successful ways that we don't afloat understand yet," she suggests.

The 2nd cistron was associated pinch humor pressure, apt connected to humor alloy building and function.

"Diving increases your humor pressure," says Aguilar-Gómez, who did this activity arsenic a Ph.D. student astatine UC Berkeley, "and peculiarly done gestation that tin beryllium very dangerous. It tin summation your consequence for preeclampsia" and different perchance life-threatening complications.

"Even if you didn't die, astir apt women that were protected against this would beryllium much apt to person much children," she says, and much apt to walk their protective genes along.

In addition, Jeju Island has 1 of nan lowest rates of changeable mortality successful each of South Korea. And since changeable tin consequence from precocious humor pressure, Ilardo thinks nan debased mortality could beryllium related to this 2nd protective gene.

"Wouldn't it beryllium astonishing if by studying divers successful Korea, we tin construe these findings to create a therapeutic that protects group from changeable astir nan world?" says Ilardo. "By studying these populations, it tin lead to discoveries that could person really important implications for group everywhere."

Stephen Cheung studies utmost physiology astatine Brock University successful Canada and wasn't progressive successful nan research. He says he finds nan activity fascinating. "By pushing nan assemblage to its limits," he says, "we get a amended consciousness of wherever those limits are, but besides conscionable what nan quality assemblage is tin of."

It's a conclusion that Aguilar-Gómez agrees with. "I'm not moreover adjacent nan property of these women and I don't deliberation I tin spell and dive each day," she says. "I consciousness for illustration that's a superpower."

Ilardo says she and her squad returned to Jeju to stock nan results pinch nan Haenyeo — whose measurement of life is dwindling — and make judge they knew nan top-line conclusion.

"These women are extraordinary," she says. "Their biology is astonishing and what they do is amazing. And truthful I deliberation it's really important to observe conscionable really unsocial and typical these women are — and really it's changed their bodies and nan bodies of different group connected this island."