The Aquatic Ape (homo sapiens)?
On March 5, 1960, professionally renowned and knighted marine biologist Alister Hardy delivered a speech proclaiming that humans evolved in an aquatic environment. Thus was borne what is today known as the ‘aquatic ape hypothesis’ of human evolution. And while there are many doubts as to this theory’s veracity, the modern version is quite compelling. As explained by the abstract to Niemitz 2010:
During the last century, approximately 30 hypotheses have been constructed to explain the evolution of the human upright posture and locomotion. The most important and recent ones are discussed here… The Amphibian Generalist Theory, presented first in the year 2000, suggests that bipedalism began in a wooded habitat. The forests were not far from a shore, where our early ancestor, along with its arboreal habits, walked and waded in shallow water finding rich food with little investment. In contrast to all other theories, wading behaviour not only triggers an upright posture, but also forces the individual to maintain this position and to walk bipedally. So far, this is the only scenario suitable to overcome the considerable anatomical and functional threshold from quadrupedalism to bipedalism. [bold added]
Niemitz goes on to show that this form of the ‘aquatic ape hypothesis’ is consistent with paleoanthropological findings, functional anatomy, energetic calculations, and evolutionary psychology. And then of course…you have all the great evidence from modern human experience.
Consider babies, neuroscience, and freedivers.
Babies. Did you know that newborns are able to hold their breath upwards of 45 seconds? It’s true, and studies suggest that newborns aren’t even apprehensive about it. Though babies lose this ability after about six months, they go on to develop a considerable amount of control over their breathing as adults, which is an involuntary reflex for many other mammals.
Then there is the evidence of ‘blue neuroscience’, or what the beautiful marine biologist Wallace J Nichols has positively termed ‘neuroconservation’. Nichols has found some really compelling evidence that suggests that our proximity to water impacts our performance, increases calm, diminishes anxiety, and increases professional success. (Keep an eye out for Wallace’s book this summer.)
Finally, freedivers. About fifty years of sport freediving has led physiologists to rewrite their text books on several occasions. For the first part of the 20th century, in fact, it was believed that freedivers could go no deeper than about 50 meters because any deeper and the pressure could crush the rib cage. Then in 1961 famed Sicilian diver Enzo Maiorca hit 50 meters, and he began a much mythologized competition with Frenchman Jacques Mayol, who later hit 100 meters in 1976.
How did they do it? We now know water pressure and temperature induce the ‘mammalian dive reflex’, consisting of bradycardia, peripheral vasoconstriction, and, perhaps most amazingly, a defensive pooling of blood in the lungs during really deep dives. And freediving continues to reveal; only recently it was found that freedivers are more adept at maintaining blood acidity levels.
So are we all just uninformed aquatic apes? We’ll perhaps never know, but what we do know is we are only scratching the surface of humanity’s potential to explore the ocean.