The Descent of Woman: A Critique

(The Descent of Woman, Elaine Morgan 1972, Stein and Day, New York)

There is an unfortunate tendency among humans to reject ideas out-of-hand that come from people who are not part of whatever group we have created. This is unfortunate because we become parochial in our views and knowledge and can make very good use of ideas and information from other disciplines.

One of the reasons why Morgan’s AAH was not well received by the scientific community was because she was an “outsider.”  It is true, Elaine Morgan (1920-2013) was an outsider to the scientific community.  She was well educated with a B.A. and an M.A. in English literature and had a successful career as a BAFTA-winning writer for television. Well versed in English literature and a competent writer she had no knowledge of science, how to think as a scientist and how a scientist presents his/her arguments to support their hypothesis, citing their sources, etc.

Morgan has made a valuable contribution to paleoanthropology by forcing us (most of whom are men) to consider the part women played in hominid evolution, and by making us rethink our theories. However, her hypothesis should not be accepted solely because it is “non-sexist” or feminist but on its ability to explain and or predict evidence and its logical consistency. Here she fails and in a large part because she is an “outsider.” She lacks an in-depth knowledge of the literature of the various disciplines she draws from neither does she have a broad background in any of them. Furthermore the way she structures her argument, the facts she uses, and the way she uses them shows her lack of understanding.

Morgan came up with the theory first then went looking for the facts to support it. Unfortunately this is how most of us do it. It is like the paranoid person, if you accept the first premise (they are being persecuted), everything else it readily explainable, or else just ignored. Supposedly the way to do it, is to collect facts and see what they show. Realistically we do start with a theory and then gather the evidence. This can work if you consider all the evidence and correct your theory to fit the new evidence. You do not adjust your evidence to fit your theory. Morgan points out, quite correctly, that proponents of the savanna hypothesis are sometimes vague about how or why hominids became bipedal or began using tools, that their theories are “just-so-stories.” However she then creates a just-so-story of her own. Some of her arguments are circular, some of her examples are irrelevant,and the sequence of when adaptations happened is confused. She picks and chooses what supports her theory and ignores the rest. She points out facts the contradict the savanna hypothesis but never the ones that might support it.

According to her, the “torrid” Pliocene set in so rapidly there was not enough time to adapt to the new conditions and survive on the savanna (all the other savanna mammals were able to adapt). Only retreating to the sea provided a buffer to give time to evolve, but we adapted to the sea instead. We became bipedal, naked, and very human in shape. There was enough time for that but no enough for more than partial webbing of the digits (for a few humans) and then the beginnings of glands to remove excess salt (tear ducts). Ten million years and “she” had hardly begun to adapt. Whales went from four-legged terrestrial mammals to a totally marine mammal in the same amount of time. Also, hominids lost their fur because it was uncomfortable when wet, tails were dispensed with because they were in the way, buttocks became enlarged because sitting on sand and rocks was uncomfortable. Things evolve because the hominids want them. This is not how evolution works. Morgan is a Lamarckian. Her theory is “simpler” than others, and that is why it is true. Her explanations are just as simplistic as the others and for the same reason. She glosses over, doing the same thing she, rightly, complains others do.

She does not understand evolution, she does not understand how to construct a logical argument. She contradicts herself and is circular. What happens early hasn’t happened yet later, her sequence of events isn’t clear and consistent. Many things occur because of a helpless, slow-growing, naked infant (apparently she assumes this to be a fact because contemporary infants are), although in the beginning the infant was similar to any other primate infant. The helpless, slow-growing part only comes with the big brain, with a bipedal female giving birth to a large-brained infant. Morgan herself says these hominids had small brains. They were ancestors to the australopithecines who had chimpanzee-sized brains and infants that grew at the same rate as chimpanzees.

Morgan explains the evolution of the human nose as an adaptation to keeping water out of our sinuses when swimming and diving. If we had noses like gorillas we could not keep water out, so we grew noses that extended out from our face and had nostrils pointed downward. This supposedly keeps water out. Seals and most (all?) other aquatic mammals use muscles to close their noses. You would think that after ten million years we would have come up with something better than a nose with slightly downward opening nostrils. I get water up my nose frequently when in the water so my nose doesn’t work real well keeping water out. Morgan points to the proboscis monkeys as an example that this is a natural way for primates to adapt to an aquatic habitat. Actually she does not claim that they are aquatic. Proboscis monkeys live in lowland rain forests and mangrove swamps and they have been seen swimming and diving in the water. They even have partially webbed feet. The noses of adults are well developed, extending beyond the lips becoming pendulous in males. The nostrils of the adults open downward, in infants the nose still turns upward. The fact that the nose does not fully develop its characteristics until adulthood and is much larger in males than in the females (sexual dimorphism) has led primatologists to assume that it is a secondary sexual characteristic (like human beards, female breasts, etc.) and is the result of sexual selection. The primary “use” of the nose is to attract the opposite sex. Why hominids with ten million years of aquatic life developed a nose no where near as large or downward pointing as the proboscis monkey, or a little bit of “webbing” between the thumb and index finger (so little I bet you never even thought of it as a web) and a small percentage of people have a little bit of webbing between their fingers, while the proboscis monkey which is not aquatic has partial webbing between all the fingers and the toes, I don’t understand. They are much more adapted to the aquatic life Morgan hypothesizes for our ancestors than we are. Maybe our nose is more of an adaptation to humidifying and removing the dust from the air of the arid and dusty savanna. The lengthen nasal passage provides more space for more hairs to trap the dust and more membranes to moisturize the dry air before it reaches the sinuses, this keeps the sinus membranes from getting excessively dry and they are more efficient at moisturizing the air before it gets to the lungs. The angle of the nostrils is just a result of what happens when a primate nose begins to protrude from the face. As for the “webbing” (that piece of skin) between the digits of our hands and feet, maybe it is just a “convenient” way to arrange the skin between fleshy digits. Morgan would say it is a holdover from our aquatic days, maybe she is right—our aquatic amphibian days.

Morgan brings up elephants and rhinos in the chapter on the hominids’ return to land (which she very casually and cursorily passes over). She uses them as possible examples of mammals which probably were aquatic and have returned to land (her own idea). Anyway she explains the baggy skin of rhinos, and also elephants, as being caused by their having lost a lot of weight. She says that if you were to “inflate them” (her words)until the skin was tight, they would resemble dugongs or seals, so they must have been aquatic and when they returned to land they lost a lot of weight and the skin hung in loose folds the same way that an obese human’s skin does when he or she loses a lot of weight rapidly. Humans are not born fat or with baggy skin. Those of us who have gained excessive weight do not have tight skin. As we get bigger (fatter) the skin grows and if we lose a lot of fat quickly, the skin does not shrink as fast and it does become loose and baggy. Apparently Morgan thinks that this becomes a gene that is past down (okay, maybe not in humans but in rhinos at least, told you she was a Lamarckian) and continues to be past down millions of years later, even though it is maladaptive. This particular point is one of the more ridiculous and senseless ones she makes. However most of the others are only a little less senseless, a little less illogical.

She also uses the pig as an example of an aquatic animal that returned to the land. The “evidence for this is the animal’s hairless-ness and fondness for wallowing when it gets hot. She is talking about the modern breeds of pigs, the ones bred by humans over the past thousand years or so, not their wild ancestor the European wild boar which is hairy. Oh wait, she did sort of mention them. Wild pigs are hairy—a coarse, sparse, scruffy fur because they “forgot” how to grow a decent fur coat while they were aquatic and now that they are terrestrial again they can’t remember how. If wallowing is a sign of an aquatic past then buffalo and elk, as only two examples of animals that wallow, must have been aquatic at one time using her logic. She picks certain examples to support her theory and ignores others that counter her examples. She ignores the implications of her own logic.

Morgan states early in her book that the savanna hypothesis for the beginnings of tool use (throwing rocks for defense) would not work because a rock would only be picked up if it happens to be there, in the field-of-view, when needed. Furthermore, it takes practice to throw accurately enough to hit your target of predator. The first time an ape throws a rock, he (her choice of gender) will miss and think that there is no point in doing that again (negative feedback/reinforcement). Without immediate success the behavior would not be repeated, the ape would never experiment and practice enough to discover the benefits, the potential of using tools (experimenting is a lot of failures, negative feedback). The savanna hypothesis does not explain the evolution of tool using behavior.

Towards the end of the book, Morgan describes how she (her choice of gender) invented containers, clay pots to be exact. (I believe that there is a very high likelihood that it was a female that invented the container, a skin bag, I have no problem with her choice of gender.) It seems Ms. Naked Ape got tired of carrying seeds, nuts, tubers, etc. back to camp a few small handfuls at a time. Then one day down at the waterhole she noticed hoof prints in the dried mud and how they held water. In a flash of inspiration, she realized that they could hold seeds and if she could dig the dried print up, she could carry it about, holding the seeds, etc. After several failed attempts because the dried mud broke (negative feedback) she gave up on that. She decided instead to make her own “footprint” that wasn’t part of the ground. She experimented with mud of various consistencies and dried in the sun (probably for varying lengths of time) to make containers. Eventually she succeeded, in spite of all the negative feedback (and the fragility of sun-dried mud). Every reason she gives for why the savanna hypothesis’s explanation for the start of tool use is not valid, applies at least as strongly in this case. She contradicts herself.

When I saw the documentary on Morgan’s AAH, I thought that the producers had probably summarized some of the major points of the theory, simplified it all to fit into the hour length of the show. The vagueness of details and the lack of good supporting data, I thought was the product of fitting the book into the medium of a TV show, and the book would be much more detailed, with more supporting facts. I was both right and wrong. The documentary was a very sympathetic presentation of the AAH. Too sympathetic in a way, the producers left out the more senseless parts, like the invention of pottery or language, and added a new fact or two, like the Danakil Depression originally having been underwater, implying that this is where the aquatic ape lived. However, the vagueness of details and lack of supporting data was not solely a result of condensing the book to a one hour TV documentary for the general public. The examples used in the show are the same ones, the only ones, presented in the book. The book itself is a bit vague, simple, and lacking in good supporting data. The book was rather clear about when we were supposedly aquatic. It was in the 10 million year long Pliocene, after the end of the Miocene and before the Pleistocene and the australopithecines. And we were marine animals not riverine, lacustrine, or esturine.

The show was wise to skim over the details of when, we have new dates on the Miocene, Pliocene, and Pleistocene, and on the australopithecines. The Miocene ended about 5mya and Pleistocene began by 2mya, if not 2.5mya. The Pliocene was no more than 3 million years long and we have australopithecine fossil as old as 4.2my and a probable ancestor 5my old or more. Oh yeah, the older fossils have been found even further from any ocean, deeper in the sub-Saharan savanna. Morgan cannot be held at fault for these changes in dates and the finding of more fossils. As a good scientist she would take these new facts into consideration and correct her theory as needed. She just ignores these, this is not science.

One last comment: the ocean was not a safe refuge from a predators. It may true that
leopards will not go into the water, but they (and lions, hyenas, and jackals) will patrol the shore for whatever they can eat. Sharks will come into shallow water at least occasionally for prey. But there is a far more dangerous and common predator that nobody has mentioned: Crocodylus niloticus. The Nile crocodile lives (or did live) in all of Africa’s rivers south of the Sahara and can live along the coasts. They still kill hundreds of humans every year, hundreds of terrestrial humans.