Elaine Morgan, a notable anthropologist, proposed a fascinating and unconventional theory known as the “aquatic ape hypothesis.” This hypothesis challenges conventional ideas about human evolution by suggesting that at some point in our distant past, our ancestors may have experienced a unique evolutionary past as island exiles, isolated after a significant event like a great flood. According to this theory, these isolated ancestors adapted to a semi-aquatic lifestyle, which led to distinctive physical and behavioral changes that set us apart from other primates.

Morgan’s hypothesis points to several key adaptations that may have developed in response to this aquatic environment:

1. Loss of Body Hair: One of the most noticeable differences between humans and other primates is our lack of body hair. Morgan suggests that this loss of body hair could be an adaptation for better buoyancy and thermoregulation in a water-based environment. Hairlessness would reduce drag when swimming and help maintain body temperature more effectively when in water.

2. Salty Tears: Humans are unique among primates in producing tears with a high salt content. This could be an adaptation to help maintain the proper balance of electrolytes in the body, which may have been disrupted by the consumption of primarily aquatic foods.

3. Subcutaneous Fat: The presence of a layer of subcutaneous fat in humans, shared with other warm-blooded aquatic creatures like dolphins and seals, could have served as an insulation layer to help regulate body temperature in a water-based lifestyle. This fat layer could have also acted as a buoyancy aid.

4. Flexible Spine: Humans possess a more flexible spine compared to other primates, which could be advantageous for a lifestyle that involves swimming and diving. A flexible spine would allow for more efficient movement in water.

5. Streamlined Body: The human body shape is often described as streamlined, with relatively narrow hips and a relatively large head. This body shape may be better suited for swimming, as it reduces resistance in water and allows for efficient movement.

6. Seal at the Back of the Nose: Humans have a soft palate at the back of the nose, which seals off the nasal passages during swallowing. This adaptation could have prevented water from entering the lungs when diving or swimming underwater.

It’s important to note that the aquatic ape hypothesis remains highly controversial within the field of anthropology. Critics argue that there is limited direct evidence to support this theory and that other factors could explain the observed traits and behaviors in humans. Nevertheless, Elaine Morgan’s theory continues to stimulate debate and further research into the evolutionary history of our species, offering a unique perspective on the potential influences of water on human evolution.