A brand new DNA evaluation of Korea’s all-women extreme divers has uncovered genetic variations that uniquely shield them from the extraordinary stresses of plunging into coastal waters with out oxygen.
The Haenyeo women dwell their complete lives diving off Jeju Island, 50 miles south of mainland South Korea, spending hours every day harvesting seaweed, abalone, and different meals objects from the seafloor.
The ladies, typically dubbed real-life mermaids, have been diving to the ocean floor, with out oxygen, for tons of of years. The apply is waning, nevertheless, and most completed divers at the moment are of their 60s and 70s.
“The apply of breath-hold diving is so integral to Jeju’s tradition that the shortening of phrases attribute of the Jeju language is colloquially attributed to the necessity for divers to speak rapidly on the water’s floor,” scientists who performed the brand new evaluation say.
Some Haenyeo divers soar into the ocean even throughout being pregnant when girls should keep away from probably deadly blood pressure situations like preeclampsia.
What precisely permits the Haenyeo girls to outlive such excessive situations has remained elusive.
Research have proven that components like relative isolation form the genetics and physiology of human populations resembling these in Greenland and Tibet.
Now, scientists have confirmed that the Haenyeo, famend for his or her outstanding diving skills in frigid waters, are one other such inhabitants that has “developed for diving”.
Usually, holding the breath whereas diving not solely limits the physique’s oxygen provide but additionally raises blood stress. In different contexts, resembling sleep apnea, holding the breath is related to pregnancy-related blood stress issues.
“This isn’t one thing that each human or each girl can do,” says evolutionary biologist Diana Aguilar-Gómez from the College of California, Los Angeles. “It’s type of like they’ve a superpower.”
“They’re completely extraordinary girls. On daily basis, they head out and get within the water, and that’s the place they work all day. I noticed girls over 80 diving off a ship earlier than it even stopped transferring,” genetics researcher Melissa Ilardo from the College of Utah provides.
The brand new examine examined whether or not the Haenyeo girls’s diving skills had been aided by genetic variations. It measured components associated to their diving means resembling blood stress and coronary heart fee and sequenced their DNA.
The examine, revealed in Cell Reviews, discovered two modifications associated to diving physiology that appeared to offer the Haenyeo benefits underwater.
One change makes the ladies over 4 occasions extra seemingly than mainland Koreans to have a genetic change linked to decrease blood stress whereas diving, retaining them and their unborn youngsters protected even once they dive throughout being pregnant.
The second genetic adaptation seems to offer them better tolerance to ache, particularly in opposition to cold-based ache.
Even when air temperatures off Jeju Island drop to round freezing level within the winter, the Haenyeo don’t cease diving.
“I requested them as soon as if they’d cease diving if it bought chilly sufficient,” Dr Ilardo stated. “They stated that so long as the wind alarm doesn’t go off, they’ll nonetheless get within the water. The wind alarm is to maintain them from blowing out to sea.”
As well as, a lifetime of apply seems to be central to what makes the Korean girls’s diving skills particular. Earlier research have discovered that lifetime divers, whether or not Haenyeo or not, expertise refined coronary heart fee modifications to preserve oxygen for longer.
However whereas an untrained particular person may even see their heartbeat decelerate by about 20 beats per minute over a simulated dive, an completed Haenyeo diver experiences a drop as much as twice that quantity, researchers say.
The most recent examine linking genetic variations to diving means may advance well being look after hypertension situations, like stroke.
“If there’s one thing about it that truly reduces the danger of stroke mortality, then we may assist individuals in all places by understanding what’s particular about these girls,” Dr Ilardo stated.
