The Bajau's Body Has Adapted to Hypoxic Conditions

The body of the Bajau people can adapt to a lack of oxygen so they can dive tens of meters into the sea without the aid of a breathing apparatus. This is because they have specific genetic variations.

The following article was translated using both Microsoft Azure Open AI and Google Translation AI.

KOMPAS/AHMAD ARIF

The Bajau people in Wuring, Alok Barat sub-district, Sikka district, East Nusa Tenggara, are preparing to sail on Wednesday (19/7/2023). The Bajau have adapted to low oxygen conditions, allowing them to dive tens of meters into the sea without respiratory aids due to their specific genetic variation.

MAUMERE, KOMPAS - The bodies of Bajau people are able to adapt to low oxygen conditions, allowing them to dive dozens of meters into the sea without the aid of respiratory equipment due to their specific genetic variations. However, the negative consequences on their health when their lifestyle changes and they no longer dive need to be further studied.

"The distinctive genetic variations found in the Bajau people were acquired through generations of their ancestors practicing diving lifestyles in the ocean," stated genetic expert from the Mochtar Riady Institute for Nanotechnology (MRIN), Herawati Supolo Sudoyo, in Maumere, East Nusa Tenggara, on Wednesday (19/7/2023)."

Herawati and her team are currently examining the genetic and health samples of the Bajau people in Wuring, Alok Barat District, Sikka Regency. The study includes the mechanisms of Bajau people's adaptation to oxygen deficiency (hypoxia) conditions and its implications for health.

Previous research by Melissa A Ilardo from the Center for GeoGenetics University of Copenhagen and her team in the journal Cell in 2018 on the Bajau people in Southeast Sulawesi found that there was special selection in the PDE10A gene. This gene increases spleen size in the Bajau, giving them a larger reservoir of oxygenated red blood cells.

Also read: The genetic manifestations of the Bajau people who can dive longer are examined

Other varied genes among the Bajau people are linked to how the body responds to diving, such as BDKRB2. One of these genes causes blood to flow more efficiently from non-essential body parts to the brain, heart, and lungs so they can continue to receive oxygen. Another benefit of this gene is the prevention of high levels of carbon dioxide build-up in the blood.

The distinct genetic variation found in the Bajau people was acquired through generations of their ancestors' lifestyle of diving in the ocean.

According to Herawati, in addition to the ability to hold their breath, the bodies of the Bajau people have also adapted to the immense water pressure. "They dive without equipment, so the pressure experienced by their bodies, including their ears, is undoubtedly very significant. In addition, their eyes may have also adapted to the minimal light conditions at great depths," she said.

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As many as 250 adult Bajau residents from Wuring Village, Alok Barat District, Sikka Regency, East Nusa Tenggara, on Monday (17/7/2023), had their genetic samples taken. In addition to blood tests, examinations were also conducted on their eyesight, hearing, lungs, neurological symptoms, muscle strength, as well as how they respond to sensitivity to taste and touch.

Lifestyle change

Currently, some of the Bajau people have undergone a lifestyle change, as seen in the Wuring Village, Alok Barat District, Sikka Regency. Even though there are still those who continue to live as divers, their frequency has decreased.

Many Bajau people work in fishing using various catching tools. Even when diving, many use compressor tools. "Those who still dive without equipment are mostly elderly. Younger people often use compressors and many of them have accidents. It's safer to do it naturally," said Dona Salong (59), a Bajau fisherman from Wuring.

Astuti Angke (76), a Bajau diver, said she was still diving without a respirator to look for sea cucumbers and spears until she is in her 50s. “I used to be able to dive up to 20 fathoms (about 20 meters). However, my sister can go much deeper, up to 30 fathoms or more. In order to go down to the bottom, we usually carry ballast, which can be from stones or debris," he said.

Read also: Sea Nomads Forced to Land

Schagatay E and Abrahamsson E's report in the journal Human Evolution in 2014 stated that the Bajau spend an average of 60 percent of their daily work time underwater. Meanwhile, the record for the deepest dive was recorded in August 2013 during a diving competition held in the city of Davao, Philippines, in the "no limits" category by the Philippine Freediving Social Network and Sinama for Sama and Bajau Laut.

The competition was participated by 18 contestants, 12 of whom are Bajau Laut men. All men in this competition can dive up to 33 meters or more. The deepest dive reached 79 meters and the longest time spent underwater was 3 minutes and 1 second. The second place finisher in the competition, a Bajau Laut from Matina Aplaya, dove up to 73 meters using only a pair of small wooden goggles.

KOMPAS/AHMAD ARIF

Young Bajau children in Wuring, Alok Barat District, Sikka Regency, East Nusa Tenggara, are currently sea fishing on Wednesday (19/7/2023). Some Bajau people have left their profession as divers and opted to catch fish using various fishing equipment.

Implication of change

Herawati explained that genetic variations found in the Bajau tribe have been proven to aid them in hypoxic conditions or lack of oxygen while diving in the sea. "Further research is needed to understand the implications of these genetic variants when the Bajau lifestyle changes and they no longer engage in diving, for example, whether it could trigger other health risks," she said.

For example, there is a thrifty gene variant in the mitochondrial genome which is thought to have arisen as a response to the human body while living as a hunter-gatherer. This gene variant helps protect against food shortages before prey is found. "However, this thrifty gene function changes when food availability is abundant and is now associated with an increased risk of diabetes mellitus," he said.

Read also: Avatar ”Born” from Bajo

Another example is experienced by people who also live in hypoxic conditions in the highlands. Almaz A Aldashev's study from the National Center for Cardiology and Internal Medicine, Kyrgyzstan, and a team at the American Journal of Respiratory and Critical Care Medicine (2022) shows that the Kyrgyz population lives in hypoxic environments due to altitudes above 3,000 meters from the sea have a higher cardiovascular risk.

“They have a higher level of hemoglobin which is needed to bind more oxygen. However, on the other hand, it turns out that it has a higher prevalence of HPH (high-altitude pulmonary hypertension failure)," said Safarina G Malik, an MRIN researcher.