DNA tests reveal the genetic underpinnings of this adaptation in the ethnic Bajau divers
In turquoise waters off the Indonesian coast, evolutionary geneticist Melissa Ilardo watched as the diver, wearing handmade, wooden goggles, spotted a giant clam meters below and darted down to retrieve it.
The diver was one of the Bajau people of Southeast Asia, known for holding their breath for long periods while spearing fish and gathering other seafood. During a typical day, these “sea nomads” spend up to five hours in total underwater. And Ilardo had heard that some can hold their breath for as long as 13 minutes during a dive. Their comfort with breath-hold diving may be due to having unusually large spleens, which provides a bigger supply of oxygenated red blood cells, Ilardo and colleagues report online April 19 in Cell.
“Many Bajau children learn to swim before they learn to walk,” says Ilardo, who did the research while at the University of Copenhagen.