Scientists have discovered that the Bajau people in Indonesia - who've been free diving with spears to catch fish for centuries - have developed extra-large spleens. This boosts the oxygen levels in their bodies and enables them to dive much deeper. Their spleens have been found to be 50 percent bigger than those of their land-dwelling neighbours. The scientists hope the findings could offer lessons for the treatment of people who suffer from hypoxia - or a sudden loss of oxygen - during operations. Melissa Ilardo from the University of Copenhagen is the lead author of the study.

Picture: A Bajau diver hunts fish underwater. Credit: Melissa Ilardo