Last week I postulated the theory of being on tippy toes leading to the shape of our foot. I laid out a hypothesis that supports the aquatic ape theory of evolution. The theory holds that we are the way we are as a result of our ancestry as creatures who spent time in water.
By its name you may have guessed the theory. As a kid I spent many hours at the Smithsonian Museum of Natural history. We lived within driving distance of Washington D.C. and my dad was always ready to take me to the mall to visit the vast rooms filled with skulls, dinosaurs and images of cavemen with raised clubs.
Whenever we saw the dioramas filled with those fur clothed cavemen, the setting was dry grassland complete with angry animals and trees somewhere in the distance. I accepted the scenes as gospel. It took a moment after a SCUBA dive that I began to question the wisdom of the “savannah theory.” I’ve worked outside in a field in the middle of summer and, even in my peak years of both age and health; I knew that I’d be more food than hunter millions of years ago. However, the time I spent at the water’s edge, or better yet, diving seemed a more natural state for my hairless, perspiring bipedal form.
Many anthropologists argue that our hairlessness actually cools our body, but science (and the sunburn that I have as I write) seems to negate that theory. If we follow Morgan’s hypothesis she claims that it was the male hunter who was out in the open, yet the slower agrarian woman is the one who became the most hairless. Anthropologists also claim parasites as a reason for the loss of hair. But, one only has to enter the dry savannah to see hairy and fur covered animals.
Morgan states, “Put [hairless bipeds] among the aquatic mammals and [they] become a conformer, obeying the laws of evolution instead of running contrary to them.” The average amount of subcutaneous fat as related to size is closer to our cetaceous relatives than our primate ones. The amount of fat that we carry also makes more sense in water as an insulating device than a heat insulator which would slow us down from predators and prey.
Morgan talks at length about the nature of the bipedal primate. We are built that way. My back hurts after a day of walking. Not so if I’m wading in water. Bipedalism in a savannah environment exposes the primate to prey and lays open those vital organs that are otherwise covered as a four-legged animal.
Both sides lend the building of the size of the brain, skull and facial structure to our upright posture. But the savannah theory falls apart with some points overlooked by Morgan. One point which I unearthed was the evolution of the septum. For those of you who have never had to have an operation on the deviated septum, or woke up with one nose completely closed up – the septum is a space in the nasal cavity which restricts airflow. What makes us unique is the horizontal alignment of the septum. Most animals have a vertical alignment to the septum. In fact many animals have a “stereoscopic” sense of smell. Each nostril, unlike we humans, run through its own chamber allowing them to identify the direction of another animal. Our unified nasal system would be a detriment to the savannah. So how does this help the aquatic ape theory? Combining the septum with our unique esophagus (I’ll talk about that in another blog) allows us to hold our breath. This is a singular talent among primates.
Finally, and what is often lost in the controversy is the very site upon which most anthropologist build their theories. One of the most popular collection of bones found by the famous Leaky has been dubbed ‘Lucy.’ These bones help build the savannah hypothesis, but not much is discussed about the artifacts that surrounded the small primate. The remains were surrounded by crocodile eggs, turtle eggs and crab claws.
I, of course, could go on. There are many other examples supporting Morgan’s theory. Her hypothesis predates much of the DNA discoveries. Indeed, there are new methods of DNA research which allows us to stitch together a detailed view of our evolution in a whole new way. In my next installment, I’ll discuss how the DNA forensics advances the Aquatic Ape Theory.