As a result of rising ocean levels, humans may be forced to adapt to an aquatic lifestyle. However, the human body is not equipped to handle the pressure and oxygen demands of underwater life. Scientists are working on technologies such as perfluorocarbon and artificial gills to enable humans to breathe underwater. There are also some human populations, like the Bajaw people, who have evolved to live semi-aquatic lifestyles. The Aquatic Ape Theory suggests that humans may have evolved from semi-aquatic ancestors, and some scientists predict that humans may evolve to live in water again due to global warming. However, significant physical changes would be required for humans to survive full-time underwater, and it's unclear if humans can adapt quickly enough to keep up with the rapid pace of global warming.
Here are the key facts extracted from the text:
1. The first creatures emerged from the oceans to live on land around 530 million years ago.
2. By the year 2100, ocean levels are expected to rise by around 2 feet (66 cm).
3. Amphipods, crustaceans that live at the bottom of the ocean, can withstand deep-sea pressure of 1125 kilograms per square centimeter.
4. The average ocean depth is around 4,023 meters below sea level.
5. At this depth, the pressure is equivalent to the weight of 14 loaded cement trucks.
6. Humans are made mostly of water, which is why we would die from gas compression in our blood and lungs at great depths, not from the pressure itself.
7. Decompression sickness, also known as the bends, occurs when nitrogen in the blood boils due to decreased pressure.
8. The surface area of human lungs is too small to extract oxygen from liquids, except for perfluorocarbon, which is 4 times richer in oxygen and carbon dioxide than human blood.
9. The Bajaw people, also known as sea gypsies, have adapted to live semi-aquatic lives for centuries.
10. The Bajaw people have a spleen that is 2 times larger than that of ordinary humans, which allows them to store more oxygen in their blood.
11. The Bajaw people can hold their breath for up to 13 minutes without equipment.
12. The Bajaw people have better underwater vision than Europeans, possibly due to their eyes adapting to life in muddy waters.
13. The Bajaw people are adapted to cold water temperatures and do not shiver due to hypothermia.
14. Some Bajaw people intentionally rupture their eardrums at a young age to improve their diving skills, resulting in many adults being hard of hearing.
15. There are other tribes, such as the Moken, Orang laut, and Urak Lawoi, that have also adapted to life in the water.
16. The Aquatic Ape Theory, proposed by marine biologist Alistair Hardy, suggests that humans are descended from semi-aquatic ancestors.
17. According to this theory, humans' straight posture and upright walking may be the result of a semi-aquatic lifestyle.
18. Human lungs capture only 17% of the oxygen in a breath, compared to 80% for marine mammals.
19. To survive 100% in the depths of the sea, humans would need dramatic and all-encompassing changes, including real gills, increased lung capacity, and a separated respiratory system.