The word Sama-Bajau refers to various ethnic groups found in the Austronesian zone of Southeast Asia. This name is used for a collective of people who call themselves ” Sama “. Their lifestyle is coastal, and they usually use small wooden sailboats for fishing.
They are found on the islands of Tawi-Tawi in the Philippines and others found in the Sulu Archipelago, east of Indonesia. This tribe is usually called “Sea Gypsies” or “Sea Nomads”. This is not only due to these people’s way of life but also because of some genetic characteristics that not everyone knows.
Generally, a familiar person can hold their breath for 1 to 2 minutes. With training, this can go up to approximately 5 minutes. However, the Bajau have spent years taking diving to an extreme that few, if any, can achieve. Its ability to hold its breath can exceed 10 minutes, even reaching 13 minutes at depths of up to 60 meters. Hence, its main modus vivendi is fishing and obtaining natural resources from the sea.
This incredible feat is not something that all of us can achieve. In the case of the Bajau, a study of their DNA carried out in 2018 revealed that this tribe has a mutation in their spleen, making them slightly larger than the human average, which gives them the advantage to dive.
The spleen regulates the number of red blood cells in the bloodstream and their recycling. This contributes to the distribution of oxygen throughout the body. Previous research has found that seals and marine mammals tend to have larger spleens due to their maritime lifestyle. Melissa Lladro, who carried out the study, decided to test her theory that if this could happen to animals, humans could develop something similar. Still, she never expected what she would find.
During a trip to Thailand, she came across the “Sea Nomads” and was impressed by their abilities. After verifying part of her theory, it was then that Melissa visited this community accompanied by an ultrasound machine and material to collect DNA. There she obtained images of the spleen of the people of this tribe. By comparing the samples from the Bajau with those found in the other related tribes, called the Sultan, who live on the main island of Indonesia, he found that the spleen of the Bajau is 50% larger, on average, than those belonging to the Bajau. Saluan.
They also found a different gene, called PDE10A, which they assume controls a hormone that allows the Bajau to have a spleen with this growth. Melissa’s new theory argues that, through centuries and natural selection, this tribe developed this genetic enhancement that benefits them with these extra minutes underwater.
While this mutation could explain the number of minutes they can spend underwater, it may also indicate why they can dive to great depths. In an average human being, the depths can increase pressure, causing the blood vessels in the lungs to fill with more blood, but on occasion, these can rupture, causing fatality. In the case of the Bajau, this does not happen due to their lifelong training and genetic improvement, experts explain.
This is why Melissa argues that these findings may have significant medical implications. The immersion reflex is similar to a common condition in hospitals called “Acute Hypoxia”. This causes humans to experience a rapid loss of oxygen. In emergency rooms, this condition claims the lives of many people. Studying the Bajau can reveal many details about this condition.
However, this tribe is outside of social norms, so most of them are illiterate, which compromises their ability to communicate with people outside their community. Although peaceful and hospitable, their way of life is threatened.
The arrival of fishing groups has threatened the environments of the Bajau, forcing them to seek other sources of food and employment, even going so far as to beg for coins that tourists throw into the sea, which they recover and keep.
Please share this note with your friends so that more people consider how little we know about our world. What do you think of these impressive humans? Let us know in the comments!