Bajau Sea Nomads genetically adapted for freediving

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A new paper published in Cell finds that the spleens of the Bajau people, the Sea Nomads of Island Southeast Asia, are significantly larger than their land-based neighbours, which has been the result of many generations of natural selection. Larger spleen size helps in diving by providing extra oxygenated blood into the body.

Physiological and Genetic Adaptations to Diving in Sea Nomads
Cell, https://doi.org/10.1016/j.cell.2018.03.054

Understanding the physiology and genetics of human hypoxia tolerance has important medical implications, but this phenomenon has thus far only been investigated in high-altitude human populations. Another system, yet to be explored, is humans who engage in breath-hold diving. The indigenous Bajau people (“Sea Nomads”) of Southeast Asia live a subsistence lifestyle based on breath-hold diving and are renowned for their extraordinary breath-holding abilities. However, it is unknown whether this has a genetic basis. Using a comparative genomic study, we show that natural selection on genetic variants in the PDE10A gene have increased spleen size in the Bajau, providing them with a larger reservoir of oxygenated red blood cells. We also find evidence of strong selection specific to the Bajau on BDKRB2, a gene affecting the human diving reflex. Thus, the Bajau, and possibly other diving populations, provide a new opportunity to study human adaptation to hypoxia tolerance.

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Spotlight on Sabah's stone age culture

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22 April 2007 (New Straits Times) – Today’s NST features a special spotlight on the stone age culture – past and ethnographic present. The first story is about the prehistory ceramics industrial site at Bukit Tengkorak (Tengkorak Hill).

New Straits Times, 22 Apr 2007

SpotLight: Stone Age Potters

Tampi villagers today don’t think twice about using clay from the foot of Bukit Tengkorak and nearby areas in southeastern Sabah for their pottery, digging wells for fresh water, burning wood for fuel and eating a wide range of fish, shellfish and molluscs.

But most of them are unaware that from about 3,000 until 2,000 years ago, people at the summit of the 600-foot hill did the same–when the Semporna peninsula was a late Stone Age population hub and craft centre.

Experts from Universiti Sains Malaysia (USM), the Sabah Museum Department and the Department of Natural Heritage have found millions of sherds which show that the site about five kilometres from Semporna town was one of the largest, if not the largest, pottery making sites in Island Southeast Asia (SEA) and the Pacific during the Neolithic era (the last part of the Stone Age, beginning 8,000 BC).

Their findings have overturned some theories about how prehistoric people lived and traded in the region.

Until the excavations here, archaeologists believed that long-distance sea trade and migration of people in insular SEA and the Pacific moved east from Melanesia (near Papua New Guinea) to Polynesia, leaving behind what is known as the “Lapita culture” of pottery, stone tools and ornaments.

“Our research at Bukit Tengkorak shows that 3,000 years ago, people were not only moving east towards New Britain in Melanesia but also westwards towards Sabah,” explains Dr Stephen Chia of USM’s Centre for Archaeological Research Malaysia, who based his PhD thesis on the site.

“This is one of the longest trading routes in the world during the Neolithic period,” says the archeochemist who found obsidian (a volcanic glass used to make tools) at the site and traced it chemically to Talasea in New Britain, 3500 kilometres away. His fieldwork in Southeast Asia also found stone tools and pottery similar to Bukit Tengkorak in the Zamboanga Peninsula, the Sulu Archipelago and Sulawesi.

The second story covers the Bajau people who live in the vicinity of Bukit Tengkorak on the Semporna peninsula of Sabah – the clay stoves produced by the Bajau are remarkably similar to the 3,000-year-old stoves unearthed nearby, implying an unbroken ceramics manufacturing tradition.

New Straits Times, 22 Apr 2007

Bajaus carrying on a long tradition

The finished handiwork of this Bajau woman in Sabah’s southeastern Semporna peninsula looks exactly like the 3,000-year-old stove unearthed at nearby Bukit Tengkorak.

“Pottery has been made like this for hundreds of years,” says Rogayah. “Each house has a stove to grill fish or satay and cook rice.”

“The way of life of the Bajaus today and the food they eat are similar to what we found on site,” says Dr Stephen Chia of Universiti Sains Malaysia’s Centre for Archaeological Research Malaysia.

“We think that the nomadic Bajau Laut may have landed here to trade, mend their nets, dry fish and bury their dead, but it was the settled coastal Bajaus who made the pottery.”
However, he cautions: “The people of Bukit Tengkorak could also be a totally different group of maritime people who shifted here and then moved on.”


Related Books:
Southeast Asia: From Prehistory to History by P. S. Bellwood and I. Glover (Eds)
Man’s conquest of the Pacific: The prehistory of Southeast Asia and Oceania by P. Bellwood