in Blog

I’m just not feeling the aquatic ape hypothesis

Reconstruction Elisabeth Daynes Paris, Photographer P. Plailly
Look at an ape and you see this furry thing that yells a lot and runs around on its knuckles. Look at a person and you see an upright creature with practically no hair and a brain that lets it write blog posts. Physiological similarities indicate there’s common ancestor, but one big question remains unanswered: what made early humans stand upright?

There are a few theories that attempt to explain why hominins abandoned walking on four limbs. The most prominent is the Savannah-based theory. Simply put, it states that early man was forced into the open grassland and had to stand upright to take in the surroundings. Hairlessness came later to help regulate body temperature. It doesn’t explain everything, but it fits the evidence comfortably enough to make everyone shrug and move along.

Back in 1942, a German scientist put forth the idea that maybe early humans were forced to live in a swamp-like environment for an extended time. We stood up to wade across the water, we lost our hair to reduce drag, we even developed a voluntary/involuntary breathing apparatus so we could dive. The Aquatic Ape Hypothesis (AAH) was born.

AAH floated around for a bit but never gained much traction in the scientific community. It wasn’t until 30 years later when Elaine Morgan got ahold of it that AAH became a “thing”. She released a book and started a life-long crusade to get everyone to believe in AAH. She used the twin tools of sarcasm and feminism to sell the message, which is exaclty how you get scientists to take you seriously. Also, that’s how you sell books. (Mental note: do those things so I can sell books.)

I won’t pick apart the rudimentary flaws of the AAH, as people better suited to do so have already done it. Instead, I’ll quote Dr. Todd Rae who had this to say about the Aquatic Ape Hypothesis:

Adding in an aquatic phase to the evolution of people is like adding yo-yo strings to gravity to explain the movement of the planets. Because the idea ‘makes sense’ to them, the data are irrelevant. That is the opposite of science.

The more I read about paleoanthropology, the more I bump into Morgan and her AAH arguments. The more I hear her arguments, the more invalid they become. She seems to spend most of her time complaining that no one takes her seriously. Her 2013 TED talk about AAH was two thirds “Scientists are daft because they won’t listen to me” and one third “Here are the main points of AAH you could have read on Wikipedia”. It came across as desperate, pushing me deeper into the “AAH=BS” camp.

I’m all for flipping the tables and rewriting theories from the ground-up, but only if there’s a damn good reason to do so. The Savannah-based theory doesn’t sufficiently explain why we’re hairless bipeds and it needs a good table turning, but AAH won’t be the one doing that. Of course, in 20 years when another fossil is uncovered, all of this could change. Heck, we could find out we were a burrowing species or that we used to have wings. Honestly, is that any less far-fetched than water apes?