Deep Diving Aquatic Nomads

[GordMay]

The evolution of the Bajau people
A recent study [1] found that, a nomadic people [the Bajau], living in the Philippines, Malaysia and Indonesia, in Southeast Asia, may have genetically evolved, to be better divers.

Unlike most humans, the Bajau live in the waters of the sea, and visiting land only occasionally, and spend 60% of their time submerged.

For this reason, the Bajau have developed an extraordinary diving ability, and can spend 13 minutes submerged, at depths of up to 60 meters

The researchers suspected the Bajau of having a biological advantage, and decided to study one organ, in particular: the spleen.

The lead author of the study, Dr Melissa Ilardo, used a portable ultrasound machine to study the Bajau’s spleens.
They found that it was 50% larger, among the Bajau, than among their agricultural neighbours, the Saluans, who live on dry land, and only enter the water occasionally.
The researchers also observed that Bajau individuals who had other activities, and therefore did not dive, had spleens the same size as their family members.

The Bajau, and possibly, other diving populations, provide a new opportunity to study human adaptation to hypoxia tolerance.

They are so familiar with their water environment, that in 2004, they were able to warn tourists of imminent danger, protecting them from the tsunami, which ravaged the coasts.

According to rough estimates, Southeast Asia has around one million Bajau people. Unfortunately, their way of life is under threat.

[1] “Physiological and Genetic Adaptations to Diving in Sea Nomads” ~ by Dr. Melissa Ilardo et al
➥ https://www.cell.com/cell/pdf/S0092-8674(18)30386-6.pdf

”Highlights
Genetic and physiological adaptations enable the remarkable breath-holding
ability of marine nomads.
The Bajau, or ‘‘Sea Nomads,’’ have engaged in breath-hold diving for thousands of years.
Selection has increased Bajau spleen size, providing an oxygen reservoir for diving.
We find evidence of additional diving-related phenotypes under selection.
These findings have implications for hypoxia research, a pertinent medical issue. ...”