The Scars of Evolution

by Elaine Morgan

  For the orang-utan has not yet entirely lost oestrus. It is not easy to detect because, being arboreal, the animals display no visual signs of it in the shape of sexual swellings. However, its presence was demonstrated in a neatly designed study. Male and female orang-utans were placed in two separate compartments of a test cage, and the doorway between the compartments was of such a size that the female could pass through it at will but the male, being larger, could not go through it at all. In previous experiments where the male had free access, copulation took place every day. When the female was able to regulate access, it took place only during a brief period in the middle of her 29-day cycle – that is, around the time of ovulation.

  This clearly indicates that the anthropological conception of being ‘permanently receptive’ has very little to do with the female and her own inclinations. In the case of orang-utans the male ignores the presence or absence of the oestrous signal because it no longer serves one of its primary purposes – that of assuring him of a welcoming and co-operative response to his advances. The chances are that he will have a fight on his hands at any time of the month, especially in the case of younger females, whenever he approaches them. Once that situation arose, the males which left most offspring would have been those which were least inhibited from using force to effect copulation, and that has become characteristic of the species. In such circumstances, frequency of copulation does not indicate that the female is permanently receptive, but merely that the male is permanently appetitive and not easily deterred. For all practical purposes, the oestrus system has broken down, and in course of time may eventually cease to exist.

  In humans it has already ceased to exist. Desire in women is no longer triggered from the inside by cyclical change in their hormonal balance. In biological terms it became irrelevant to species survival: male desire was sufficiently active and dominant to ensure that females reproduced their kind whether or not they invited or welcomed the process of procreation. When any biological feature becomes irrelevant to survival, the forces of natural selection cease to exercise any influence over it, whether in the direction of changing it or stabilising it. One result of this may be a wide degree of variation in the feature as between individuals. An example is the vermiform appendix – a hollow blind-ended tube attached to the large intestine. In man, since it has ceased to perform its original function (the digestion of cellulose), it has become vestigial and relatively unpredictable in form. Its average length is between three and four inches, but it may in some cases be as long as seven inches, and in others virtually non-existent.

  It is highly likely that the strength of sexual desire in women is subject to innate variation. But this is hard to quantify because of the powerful influence of social conditioning. The conditioning factors include early upbringing, education, social and cultural backgrounds, peer group pressures and life events, especially those experienced during childhood and puberty. The same factors affect males but to a lesser degree because the instinctive component in their sex behaviour is less eroded.

  Women discussing their experiences of love and sex are liable to encounter barriers of incomprehension when talking to women from very different cultures – or even, in an era of rapid social change, to women of different generations. There is a prevalent idea that somewhere in the world there must be, or have been, a subsection of womankind which got it right, exercising simple natural sexual responses, able to illustrate the ‘real truth’ about what makes all women tick. If that were true, the corollary would be that all other women before them – or after them, or living elsewhere, or dissenting from them – have always been self-deluded, or brain washed, or telling lies.

  That is a fallacy. It is like believing that somewhere in the world is a tribe or race speaking the language that Nature intended people to speak, from which all the rest of us have deviated. But it is a fallacy widely believed in, and women are under pressure to conform to the current stereotype for fear of being castigated in one century for unnatural depravity, in another for unnatural frigidity.

  To return to the question of frontal sex, the signs are that in Homo the transition to this mode happened much earlier than in the orang-utan, so that we have had several million years in which to adjust to it, both behaviourally and physically. We have evolved subtler methods, verbal and non-verbal, of communicating our intentions to one another. And in the course of evolution the human vagina has swung forward to accommodate ventro-ventral copulation, so that its axis now forms an angle of more than 90 degrees with that of the uterus instead of being in a straight line with it, as in most quadrupeds.

  If, as this suggests, the change occurred at an early stage of hominid speciation – possibly before Lucy – it is conceivable that when it first took place the females’ responses could have been as disturbed and resistant as the orang-utan’s, and equally disruptive of sexual harmony. Perhaps we should count among the scars of our evolution the atavistic psychological link between sex and violence which appears to be a human characteristic but is certainly not part of the general mammalian inheritance.

  In most wild animals sex and hostility are incompatible. Sexual activity may give rise to hostility between males, but not between the partners in the sex act. In the majority of quadrupeds rape is unknown. Not only is there no incentive for it (because of oestrus), but it is a physical impossibility. If a mare or a vixen or a she cat does not want to be mated, she has only to hold her tail down and keep running – or even keep walking – and it cannot happen. If she is receptive, she stands still. We belong to the small minority of animal species in which rape is possible, and to the still smaller minority in which it occasionally takes place.

  Some people find it distasteful even to think of these matters in terms of our own animal origins. Humans are endowed with intelligence, and foresight, and sensitivity. We are not at the mercy of our instincts. Loving relationships between humans are of infinitely greater complexity than relationships between animals.

  But the fact that they are not purely instinctive behaviour patterns is no guarantee of a foolproof system – rather the contrary. Instinctive behaviour can exhibit a remarkable degree of efficiency and reliability. The near-perfection of a swallow’s navigation, a spider’s web, or a weaver bird’s nest is achieved precisely because these functions depend on an innate capacity and do not have to be learned. In lower species the same is true of sex.

  But in many primates, including man, sex is a learned activity, and not one for which they are fully programmed at birth. If monkeys are reared in isolation from their own kind up to the age of two years and then brought into contact with one another, they never discover by themselves through trial and error how to copulate. Some of the female isolates may finally mate successfully if partnered by a proficient male, but the male isolates never achieve intromission.

  Much the same is true of Homo sapiens. In Victorian days there were rare cases (documented in medical records) of young men strictly reared who grew to adulthood without ever having been told the facts of life, and when they married young women equally ill-informed the union remained unconsummated. In a species where so powerful an urge is accompanied by so little instinctive knowledge of what to do about it, there is a tendency for the elders of the tribe to issue their own list of instructions and proclaim that any who depart from it are accursed.

  People who try to prescribe or reform sexual mores often claim that the behaviour they advocate is what Nature intended, as if that were in itself a sufficient recommendation. It is not really a very good criterion. ‘Nature’ – as the personification of our own evolutionary inheritance – is not all-wise. She proceeds by devising ad hoc solutions to environmental crises and vicissitudes, and they are often remarkably successful. But in the sphere of sexual relationships she has endowed us with a confused and messy legacy.

  The human problem is how to make the best of it in the rapidly changing modern world. Perhaps it is time to ignore where we have come from and concentrate on wh
ere we want to go. After all, the peculiar weaknesses of our species are more than counter-balanced by its peculiar strengths which are still under-exploited – the ability to think, to communicate, and to foresee the long-term consequences of our decisions on our own well-being and that of our successors.

  13

  The Aquatic Ape Theory – the Counterarguments

  ‘Often the older scientists of the discipline

  are unable to make the switch; they feel

  strong hostility to the new paradigm and its

  supporters; and matters are only resolved as

  the old-timers die off (Plank’s Principle).’

  Michael Ruse

  Plank’s Principle means that a whole generation frequently elapses before the scientific community is prepared to consider a new hypothesis dispassionately, on its merits. In that intervening period the reception accorded to the unfamiliar idea has little to do with merit. Stephen Jay Gould has described the early reactions to Wegener’s theory of Continental Drift (see p.50)

  During the period of nearly universal rejection, direct evidence for continental drift – that is, the data gathered from rocks exposed on our continents – was every bit as good as it is today. It was dismissed because no one had devised a physical mechanism that would permit continents to plow through an apparently solid oceanic floor … Since drift seemed absurd in the absence of a mechanism, orthodox geologists set out to render the impressive evidence for it as a series of unconnected coincidences.

  That is happening again today in the life sciences. There is an impressive list of unusual features in the human body which need to be accounted for – nakedness, bipedalism, fat, tears, the sebaceous glands, the descended larynx, the vanished apocrines, and so on. The Aquatic Ape Theory (AAT) suggests that a single factor may account for the great majority of them. Orthodox theories leave a number of them unaccounted for, and for the rest they persist in attributing the multiplicity of unique features to a multiplicity of possible causes, as a ‘… series of unconnected coincidences’.

  A theory which obviates the need to postulate unconnected coincidences is said to possess the scientific virtue of parsimony. It was this aspect of his own theory which kept Darwin going when his ideas met with scepticism. He wrote: ‘I must freely confess, the difficulties and objections are terrific; but I cannot believe that a false theory would explain, as it seems to me it does, so many classes of facts.’

  One kind of response to an unwelcome idea is to ignore it, and this can be very effective. If the new concept has nothing going for it except the vividness of the creator’s imagination, it will sink into oblivion. This policy was initially applied to AAT and appeared at first to be successful.

  In 1930, when Alister Hardy as a young marine biologist conceived the idea of an aquatic phase in human evolution, his friends warned him that publishing such a heresy would mean committing professional suicide. As he admitted in later years, ‘I wanted a good professorship. I wanted to be a member of the Royal Society.’ So he kept quiet about it for the next thirty years. When he finally published his idea in 1960 the response from the scientific community was nil.

  Meanwhile, the same possibility had been considered in Europe. It is not unusual, in the case of an idea whose time has come, for it to occur independently to more than one person. (The most famous example is that of Natural Selection, which was developed independently by Charles Darwin and the naturalist Alfred Russel Wallace.) A German professor, Max Westenhöfer, wrote a book on human evolution in 1942, which included a chapter on the aquatic hypothesis. It was ignored so successfully that few people outside Germany learned about it, and Hardy died without ever knowing that he had not been the first to publish the idea.

  Nevertheless, the aquatic hypothesis refused to go away. Despite the chilly reception accorded to it, it survived and gained adherents. The time came when tutors in Anthropological seminars began to complain of a recurring nuisance – the kind of enquiring student who would stand up and ask questions about AAT.

  The strongest response would have been to say: ‘We can explain all the anomalies more elegantly and convincingly without needing to postulate an aquatic detour, and here are the explanations.’ Instead of that, students were liable to be told: ‘The explanations are all there in the literature – go away and look them up.’ One object of writing this book has been to come to the aid of such students by saving them a lot of time and trouble. To the best of my knowledge, all the non-aquatic explanations to be found in the literature have been indicated in the previous chapters.

  Another response is a refusal to discuss the matter on high philosophical grounds. AAT, it is claimed, does not merit attention because it is not, in the true sense, scientific. It makes no ‘verifiable predictions’; it ‘can never be falsified’; it changes its arguments in the light of new discoveries; the convictions of its adherents ‘cannot be shaken by contrary evidence’.

  This is an intimidating catalogue, indeed – until you apply the same criteria to the scientific credentials of the savannah theory. It, too, has made no verifiable predictions; it, too, alters its scenario with every new discovery. The savannah carnivore becomes a savannah seed-eater; the hominid slowly evolving on the plain becomes a hominid evolving there with spectacular speed; the large-brained tool-user gradually turning into a bipedalist is transformed into a weaponless biped gradually acquiring a large brain.

  Through all these vicissitudes nothing shakes the conviction of the savannah theory supporters that basically they have been right all along and are still right. There is no basis whatever for the claim that the savannah theory is in some mystic sense sounder or ‘more scientific’ than AAT.

  For some hard-working anthropologists, Hardy’s idea is disqualified from being taken seriously by the manner in which he arrived at it, and by the enthusiasm of some who accept his ideas. He came home from an Antarctic expedition, opened a book by Frederick Wood Jones, and almost at once all the things he knew about man and evolution rearranged themselves into a new pattern in his head.

  His critics feel that in this day and age scientists do not and should not receive enlightenment in this dramatic fashion, like St Paul on the road to Damascus. New truths, they maintain, should be vouchsafed only to those who have earned them by years of painstaking endeavour – and by themselves providing some of the new data paving the way to the new theory. After all, it is urged, we are not living in the age of Archimedes, and the man Hardy was not even an anthropologist. He was a marine biologist, and should have stuck to his own speciality.

  But the ‘Eureka’ experience did not go out of fashion with Archimedes. The idea of natural selection occurred to Alfred Russel Wallace during a bout of malaria in the East Indies in 1858, and the impact of it shot him out of his sickbed in search of pen and paper and a candle. When he related this to Charles Darwin, Darwin pointed out to him the precise spot where he himself, when riding in his carriage, had experienced the same excitement.

  Michael Ruse, in The Darwinian Paradigm, relates what happened in the present century when Wegener’s half-forgotten ideas resurfaced. ‘We have seen already how liberating and exciting geologists find their new theory, and it seems clear that many of them come to the theory by something very much akin to a conversion experience.’ One researcher, Tanya Atwater, who was in at the beginning of the geological revolution, recalls:

  It is a wondrous thing to have the random facts in one’s head suddenly fall into the slots of an entirely orderly framework. It is like an explosion inside … I took my ideas to John Crowell on Thanksgiving Day. I crept in feeling very self-conscious and embarrassed that I was trying to tell him about land geology starting from ocean geology, using paper and scissors. He was very patient with my long bumbling, but near the end he got terribly excited and I could feel the explosion in his head. He suddenly stopped me and rushed into the other room to show me a map of when and where he had evidence of activity on the San Andreas system. The predicted pattern was
all there. We just stood and stared.

  There may be scientists so austere that they would merely have lifted an eyebrow. But it is clearly untenable to imply that any idea which generates the sensation of an explosion in the head must ipso facto be invalid.

  More recently some scientists have abandoned these abstract admonitions and begun to address themselves to the evidence. Sometimes they repeat the error of bringing charges against AAT which could equally be levelled against orthodox theory.

  For example, it has been asserted that a naked skin cannot be regarded as an aquatic adaptation because not all aquatic mammals have lost their hair. By that same reasoning it certainly cannot be regarded as a savannah adaptation.

  Similarly, the argument that ‘man’s ancestors can never have been aquatic because some people fear water’ is no more valid than ‘man’s ancestors could never have been arboreal because some people are afraid of heights’. The more substantial arguments are advanced by those who are willing to try to analyse their instinctive rejection of AAT, and to give reasons why they think the aquatic interlude could never have taken place.

  One such contention is that an aquatic ape could never have survived because it would have died of cold. Primates, the argument runs, are homeotherms and have to maintain a minimal blood temperature or perish; in water they would be in danger because water conducts heat away from the body more rapidly than air does. Data are produced purporting to prove that in water at a temperature below 28°C the body’s core temperature will begin to decline, and that any figure below 23°C entails imminent danger of death from cardiac arrest.