Mystery of sea nomads’ amazing ability to freedive is solved

“Scientists have uncovered the secrets of the Bajau people, long-famed for their ability to hold their breath for extraordinary lengths of time.”

From The Guardian:

The secret behind the ability of a group of “sea nomads” in Southeast Asia to hold their breath for extraordinary periods of time while freediving to hunt fish has finally been revealed – and it’s down to evolution.

The Bajau people are able to dive tens of metres underwater with no conventional diving aids. Instead they rely on weights, handmade wooden goggles — and a single breath of air.

But while the Bajau people’s talents have long been known, it was unclear whether the skill was the result of practice, as in the case of the excellent underwater vision of Thai “sea nomad” children, or the result of adaptations which have their roots in the Bajau people’s DNA.

Now experts say they have the answer: over time the Bajau people have undergone natural selection, resulting in certain versions of genes becoming widespread — many of which are linked to biological changes, including having a larger spleen, that could help the Bajau to hold their breath underwater for many minutes at a time. […]

Writing in the journal Cell, the scientists reveal how they unpicked the mystery following a clue from previous research: species of seals which can dive for longer have larger than expected spleens — an organ which, among its functions, can store oxygen-carrying red blood cells.

As a result the team used an ultrasound device to measure the spleen in 43 Bajau people and 33 people from a neighbouring group of farming people, the Saluan.

“The spleen size is about 50% larger in these sea nomads than it is in the [Saluan], so already it was like ‘Oh my God — it is really [an] extreme physiological characteristic,” said Prof Eske Willerslev, a co-author of the study from the University of Cambridge.

Read the whole thing …