The Bajaus, a unique Southeast Asian community, are challenging traditional scientific concepts with their exceptional diving skills and surprising biological adaptation. With an estimated population of around one million people, the Bajaus inhabit the coastal waters of Malaysia, the Philippines' Sulu archipelago, Mindanao, Borneo, and eastern Indonesian islands.
Since Antonio Pigafetta first mentioned them in 1521, the Bajaus, known as “sea nomads,” have lived and survived predominantly by fishing and collecting crustaceans and natural elements for crafts. Some groups still follow a traditional lifestyle, residing in houseboats or huts on wooden stilts.
The Bajaus can dive up to 60 meters deep and remain submerged for up to 13 minutes, using only rudimentary equipment such as wooden masks and weight belts. This ability aroused the interest of researcher Melissa Llardo from the Center for Geogenetics at the University of Copenhagen. In 2018, Llardo published a groundbreaking Cell study investigating the genetic and physiological adaptations that allow Bajaus these extraordinary abilities.
The study compared 59 Bajau saliva samples with 34 samples from a neighboring farming community, the Saluan, for DNA analysis and ultrasound examinations of the spleens, revealing that the Bajau organ is, on average, 50% larger.
The spleen, an organ responsible for filtering microorganisms from the blood and producing defense cells, also acts as a reservoir of oxygenated red blood cells, essential for providing oxygen during long underwater excursions.
When we hold our breath, several physiological changes occur in our bodies: our heart rate slows, blood vessels constrict, and the spleen contracts, releasing oxygenated red blood cells into the bloodstream. Thus, the larger the spleen, the greater the oxygen available during underwater activity. Previous studies have indicated that marine mammals such as seals also have disproportionately large spleens, an adaptation that appears to apply to the Bajaus.
Genetic analysis identified 25 significant differences in the Bajau genome compared to other groups. The discovery of genes such as PDE10A, associated with increased spleen size in mice, suggests a unique evolutionary adaptation in the Bajaus. This trait results from the environment and a genetic advantage developed over millennia of natural selection.
“The Bajaus are almost like superhumans living among us, with extraordinary capabilities,” comments Melissa Llardo. “Natural selection is a powerful force that has shaped these adaptations and may offer valuable insights for future treatments of respiratory disorders.”
These findings highlight not only the extraordinary adaptability of the Bajaus but also the importance of exploring natural selection in modern human populations. The study sheds light on the complexity of human evolution and offers promising prospects for future medical and biological research.
This study honors the Bajaus' inherent curiosity. It promises to bridge the gap between Western science and the traditional knowledge of Indigenous communities, celebrating the rich diversity and human resilience in the modern world. Indigenous communities' traditional knowledge
References:
Comments