South Korea’s Deep-Sea Diving (including pregnant) Women Show Genetic Traits for Cold Water Endurance

Amazing stuff! Genetics influences phenotype and vice versa. Some of these women appear to be working until high age (see photo below).

"Just off South Korea’s southern coast lies Jeju Island, home to a community of women divers known as Haenyeo, or “women of the sea.” These women are trained at a young age in free diving into the frigid sea to harvest shellfish, even while pregnant. As Tibetans adapted to high altitudes and Bajau divers developed underwater endurance, researchers wondered if generations of diving shaped Haenyeo physiology through training, genetics, or both. ...

a team of researchers found two gene variants associated with cold tolerance and decreased blood pressure that likely aid Haenyeo while diving. ..."

"Highlights

• Evidence of selection that may increase the safety of diving during pregnancy

• Regular diving increases the magnitude of bradycardia in response to dive stimulus

• The Haenyeo may represent the second known population evolved for diving

Summary

Natural selection and relative isolation have shaped the genetics and physiology of unique human populations from Greenland to Tibet.

Another such population is the Haenyeo, the all-female Korean divers renowned for their remarkable diving abilities in frigid waters. Apnea diving induces considerable physiological strain, particularly in females diving throughout pregnancy.

In this study, we explore the hypothesis that breath-hold diving has shaped physiological and genetic traits in the Haenyeo. We identified pronounced bradycardia during diving, a likely training effect.

We paired natural selection and genetic association analyses to investigate adaptive genetic variation that may mitigate the effects of diving on pregnancy through an associated reduction of diastolic blood pressure.

Finally, we identified positively selected variation in a gene previously associated with cold water tolerance, which may contribute to reduced hypothermia susceptibility. These findings highlight the importance of traditional diving populations for understanding genetic and physiological adaptation."

Korea’s Deep-Sea Diving Women Show Genetic Traits for Cold Water Endurance | The Scientist "Nature and nurture give Korea’s women divers, known as Haenyeo, an edge in deep-sea diving with high cold tolerance and low blood pressure."

Genetic and training adaptations in the Haenyeo divers of Jeju, Korea (open access)

Graphical abstract

Jung Sun-ja, 84, Yoon Yeon-ok, 74, and Ko Keum-sun, 69, pose after working in the sea in Busan, South Korea