The Bajau, also known as “Sea Nomads”, have adapted so much to ocean living that their bodies have genetically modified to allow them to dive to depths of 230 ft. for up to 13 minutes with nothing but a spear

Scientists have found evidence that some humans have genetically adapted to diving by studying the Bajau, a group of people indigenous to parts of Indonesia. The Bajau, also known as ‘Sea Nomads’, have enlarged spleens that allow them to dive to depths of up to 70 m (230 ft.).

Melissa Ilardo spent several months in Jaya Bakti, Indonesia taking genetic samples and performing ultrasound scans of the spleens of both the Bajau and their land-dwelling neighbors, the Saluan. She had a hunch that the Bajau had genetically adapted in order to be able to dive to staggering depths. Carrying only a spear, some weights, and wood goggles, some Bajau divers can stay underwater routinely for 15 minutes. They have been living this hunter-gatherer way of life for thousands of years.

The spleen is directly related to how long a person can dive. When the human body is submerged under cold water, even for just a few seconds, it triggers the so-called ‘human dive response.’ During this state, the heart rate slows down, blood vessels in the extremities shrink, and the spleen contracts. This latter action of the spleen gives the body an oxygen boost — up to 9% extra O2 — by ejecting oxygenated red blood cells into the bloodstream, thereby prolonging dive time.