I would like to extend the Aquatic Ape Theory a bit. The Aquatic-Ape Theory conjectures that the reason humans evolved an omnivorous diet, lost their fur, developed subcutaneous fat for insulation, developed breath management capability, developed the dive reflex, developed a more streamlined upright posture and changed their sexual anatomy, was all due to the requirement to move from life in the trees or on the savanna, to an aquatic life in order to survive a severe prolonged drought resulting from climate change.
We may not have extensive fossil evidence of aquatic apes because of the radical changes in the shoreline of the oceans that have occurred over time. Some of these ocean level & shoreline changes have been very extreme & rapid due to extreme changes in average temperatures in short periods of time. Much of the fossil record has probably been lost, particularly for a semi-aquatic species living near the seashore; their bones would likely be under hundreds of feet of ocean.
First of all, I call it the Semi-aquatic Ape Theory. Protohumans didn’t become fully aquatic which is evidenced by our need to have the entire brain sleep deeply while we are asleep . Dolphins, also aquatic mammals, allow one hemisphere of their brain to sleep while the other hemisphere is awake so they can always stay at least partially awake, to surface to breath and avoid predators. We sleep deeply and thus semi-aquatic protohumans had to return to land at least in the evenings to sleep and to avoid predators. Thus these protohumans were semi-aquatic, not fully aquatic.
I believe one of the biggest drivers of evolutionary change experienced by these semi-aquatic protohumans was due to the change in diet and corresponding parasite load.
Stay with me; suspend your disbelief! It is my contention that most animals communicate with close companions via mental communication i.e. telepathy. I know this is considered a crazy idea. I believe animals use their relatively limited vocalizations to communicate over distances and to communicate threats. For close quarter interactions with companions they experience each others’ mental states directly in the moment. We have all experienced at one time or the other when the mental energy from others in the area around us has been strong ie. threats, fear, anger, grief, euphoria, etc., maybe at a funeral, a sporting event, a verbal or physical fight, or in war. We were experiencing other peoples’ mental state in that moment. Humans that reach a high state of mental, physical and emotional health and are clean living with meditation, raw foods, fasting, etc. achieve a similar ability to experience even others very subtle mental states regularly. Ok, you can return to your normal sneering skeptical state now!
When protohumans came down out of the trees or maybe left the savanna and went to the seashore during the desertification that occurred, they had to gather foods that they were not accustomed to. Chimpanzees now eat maybe 5% of their diet that is not vegetarian. But suddenly on a very short evolutionary time scale, these semi-aquatic protohumans had to convert to consuming a largely omnivorous diet – any birds, rodents, eggs, fish, roots, seaweed or fruits and leaves that they were lucky enough to catch or find. This radical change in diet had severe consequences.
The biggest problems for them were the new parasites that these new animal foods in their diet provided. This had a huge impact on their health. Brains of sick beings don’t function well. Semi-aquatic protohumans under this load of parasitism had weak cognitive function. They lost the ability to communicate mentally. They were reduced to verbal communication while, at the same time, they developed the ability to control their breath due to the requirements of an aquatic environment. The urgent need to cooperate in this new environment necessitated that they communicate verbally. This is the origin of language.
Once they were communicating by voice instead of by in-the-moment mental communication, it gave these protohumans the ability to communicate about the present, future and the past. Communicating in multiple time domains facilitated urgent complex cooperation and transmission of knowledge.
The protohumans living in, what was for them, an alien environment had to develop new skills or die. Weapons were one of those urgent skills. They were not fast enough to grab a fish, or big enough to take on a saltwater croc or shark. There was limited ability to avoid predators either on land or sea, when they lived on the seashore. They needed simple weapons to compete, ie a sharpened stick for a spear or a knife. So this new environment forced them to weaponize.
Another skill was an upgrade in shelter. Without fur and limited to the insulation of subcutaneous fat, and spending large periods of the day wet hunting for food, they needed better shelter. They had to return to land at night to sleep. So they had to find shelter for safety and to stay warmer. Particularly suitable shelter would have been caves which gave them protection on four sides from weather and predators. Thus the change in shelter from living in trees to shelter in a home-like environment like a cave.
The big turning point was the discovery of fire. Prior to this, their weakened parasitised state made them susceptible to night attacks by predators while they slept.
Developing fire technology had at least three benefits for these semi-aquatic protohumans. First, it gave them protection. Light a fire at the opening to a cave and you no longer spend the night fearing predator attacks, thus better sleep and more energy!
Second, they started cooking their food which solved most of the parasite problem and gave them a wider range of food choices. Now they could digest meat and fish more easily. And without the parasite load, and being more digestible they extracted more calories and protein from these foods. Cooking gave them the ability to eat what they couldn’t before, such as some hard indigestible roots or seaweed, and to extract more nutrition from some other foods that needed to be broken down to be more digestible.
Finally it gave them a way to process their tools, such as hardened wooden spear points and hardened clay for pots.
Cooking enhanced the digestibility of foods for protohumans who didnt have the extremely acidic stomachs of a natural carnivorous predator. While releasing the amino acids and calories cooking also adds certain toxins and removes many enzymes from the food. Better sleep is very salutatory. All of this put these semi-aquatic protohumans in a state of better health with more energy, that allowed them to function on a much higher level than before. Unfortunately fire and a cooked food diet didn’t allow them to recover fully their ability to communicate mentally.
The rest is common history. You had tool-making, weaponized, communicating, cooperating, strategizing (talking about past, present and future), energetic omnivorous bipedal apes, adaptable to any environment. with manual dexterity, that took over the world. They were ready and able to migrate when the climate changed again and the deserts changed to forests and savannas.
I have a funny side theory that the reason we retained thick long hair on our heads was for three reasons. One is protection from overhead intense sunlight. Another advantage is that one could tie one’s baby into the long hair freeing up the one’s arms for swimming, hunting and searching. Finally, imagine one has made a dive and is searching for fish underwater. A fish would only see this amorphous mass of hair which might look like seaweed, and thus the hair would act as camouflage allowing this semi-aquatic protohuman to sneak up on their prey with their spear, to eat and live another day.
Roger C. Barr
August 16, 2020