'Sea Nomads' Are First Known Humans Genetically Adapted to Diving
If you hold your breath and plunge your face into a tub of water, your body automatically triggers what's called the diving response. Your heart rate slows, your blood vessels constrict, and your spleen contracts, all reactions that help you save energy when you're low on oxygen. Most people can hold their breath underwater for a few seconds, some for a few minutes. But a group of people called the Bajau takes free diving to the extreme, staying underwater for as long as 13 minutes at depths of around 200 feet.