Quite a few years ago I ran across a book – I can’t recall where – called The Descent of Woman, by Elaine Morgan. Published in 1972, it puts forward a most unusual idea about human evolution, and it’s worth a mention here. I’m curious to know if any of you are familiar with it.
I think that Morgan, a Welsh feminist writer, wrote the book as a response to what she saw as an androcentric bias in Desmond Morris’s The Naked Ape. But the book attracted more attention for its defense of an idea that had been knocking about for about thirty years at the time: the “aquatic ape” theory, which says that the ancestors of modern humans spent a critical period of their evolutionary history living in the water.
Morgan adduces an impressive list of observations to buttress the claim. Here are a few:
- Of almost two hundred species of monkeys and apes, every one but us is covered with hair. Aquatic mammals, however, tend to be hairless.
- The voluntary control that humans have over their breathing is apparently unusual among mammals, again with the exception of those that live in the water. This voluntary control of the breath, Morgan argues, was a necessary precursor to the complexities of human language.
- Humans further resemble aquatic mammals in their distribution and retention of body fat. Also, central body fat in humans is not attached to the muscles, as in most land mammals, but to the skin, as in aquatic mammals.
- Humans are the only mammals that are capable of truly upright bipedal locomotion, and Morgan suggests that the transition occurred during the period that our body weight was being supported by water. Monkeys and gorillas walk upright when wading.
- Human babies at birth are covered in the waterproof and waxy substance vernix, a trait we share with seals.
Morgan was not trained as an anthropologist, and her book was greeted with scorn and derision from the professional community. Shortly after reading the book, which I have to say I found quite persuasive, I had an opportunity to mention it to Stephen Jay Gould, who said, with a contemptuous snort, “Oh no – not that awful book!” When I replied that it seemed to me to make quite a few cogent arguments, he pointed out one serious objection to the theory, namely that mammals that become aquatic quickly lose leg strength and size, whereas humans have very large and powerful legs.
One recollection that has just swum into mind (I can’t recall for certain if it came from this book – actually I think it might not have, but now that I’ve thought of it, it’s interesting enough to mention) is an explanation of why the hair on our bodies is arranged in the way it is. For example, the hair on our legs points down, toward our feet, but the hair on our forearms and the backs of our hands tends to lie pointing up the arm, away from our fingers. The suggestion I recall being given was to imagine a naked human covering himself in a rainstorm, seated on the ground in the most abject position. With knees drawn up, elbows together, hands upon the head, and the head tilted forward, all the hair, from the crown of the head on down, is aligned earthward.
Elaine Morgan has, in later years, taken aim at what she considers “right-wing” science, as exemplified by Pinker, Dawkins, et al. In fact her newest book is called Pinker’s List, and is a direct response to The Blank Slate.