Note

These are highlights imported from my kindle, Probably makes a lot more sense if you have read the book.

The Red Queen

Sex and the Evolution of Human Nature

Author: Mat Riddley

  • Like engineers telling bumble bees they could not fly,

Meiosis

  • One more technical term is essential: [[Meiosis]], which is simply the procedure by which the male selects the genes that will go into a sperm, or the female selects the genes that will go into an egg. The man may choose either the 75,000 genes he inherited from his father, or the 75,000 he inherited from his mother, or, more likely, a mixture. During meiosis something peculiar happens. Each of the 23 pairs of chromosomes is laid alongside its opposite number. Chunks of one set are swapped with chunks of the other in a procedure called recombination. One whole set is then passed on to the offspring to be married with a set from the other parent: a procedure known as outcrossing.

  • [[Coelacanth]], a fish that lives off Madagascar and looks exactly like its ancestors of 300 million years ago,

  • teleology

  • A gazelle on the African savannah is trying not to be eaten by cheetahs, but it is also trying to outrun other gazelles when a cheetah attacks.

  • dichotomy.

  • grasses that only set seed when fertilized by pollen from a related species, but the seed inherits no genes from the pollen. It is called pseudogamy.

  • Strawberry plants and the animals that build coral reefs sit in the same place all their lives, but they send out runners, or coral branches so that the individual and its clones gradually spread over the surrounding space. However, when they want to send their young much further away, in search of a new, pristine habitat, the strawberries produce sexual seeds and the corals produce sexual larvae called planulae. The seeds are carried away by birds; the planulae drift for many days on the ocean currents. To Williams, this looked like a spatial version of the lottery: those who travel furthest are most likely to encounter different conditions, so it is best that they vary in the hope that one or two of them will suit the place they reach. Elm trees and oysters, which are sexual, produce millions of tiny young that drift on breezes or ocean currents until a few are lucky enough to land in a suitable place and begin a new life. Why do they do this? Because, said Williams, both elms and oysters have saturated their living space already. There are few vacancies on an oyster bed and few clearings in an elm forest. Each vacancy will attract many thousands of applicants in the form of new larvae or seeds.

  • Sex gives variety, so sex makes a few of your offspring exceptional and a few abysmal, whereas asex makes them all average.7

  • Aphids and monogonont rotifers both turn sexual not when winter or drought threaten, but when overcrowding affects the food supply. You can make them turn sexual in the laboratory just by letting them get too crowded.

  • Ghiselin suggested that most creatures compete with their brothers and sisters, so if everybody is a little different from their brothers and sisters, then more can survive. The fact that your parents thrived doing one thing means that it will probably pay to do something else because the local habitat might well be full already with your parents’ friends or relatives doing their thing.10 Graham Bell has called this the ‘tangled bank’ theory,

  • Mixtures of different varieties generally yield more than a single variety does; plants transplanted to different sites generally do worse than in their home patches, as if genetically suited to their home ground; if allowed to compete with each other in a new site, plants derived from cuttings or tillers generally do worse than plants derived from sexual seed, as if sex provides some sort of variable advantage.13

  • To conclude anything from such observations would be to fall into the trap that philosophers call ‘the fallacy of affirming the consequent’.

  • In the 1970s, evolutionary biologists realized that species do not change much. They stay exactly the same for thousands of generations, to be suddenly replaced by other forms of life.

  • The discovery was that the probability that a family of animals will become extinct does not depend on how long that family has already existed. In other words, species do not get better at surviving (nor do they grow feeble with age, as individuals do). Their chances of extinction are random.

  • The Red Queen is a formidable woman who runs like the wind but never seems to get anywhere: ‘Well, in our country,’ said Alice, still panting a little, ‘you’d generally get to somewhere else – if you ran very fast for a long time, as we’ve been doing.’ ‘A slow sort of country!’ said the Queen. ‘Now, here, you see, it takes all the running you can do, to keep in the same place. If you want to get somewhere else, you must run at least twice as fast as that!’20

  • Sex, according to the Red Queen theory, has nothing to do with adapting to the inanimate world – becoming bigger, or better camouflaged, or more tolerant of cold, or better at flying – but is all about combating the enemy that fights back.

  • The things that kill animals or prevent them reproducing are only rarely physical factors. Far more often they are other creatures – parasites, predators and competitors.

  • The ‘great war’ of 1914–18 killed twenty-five million people in four years. The influenza epidemic that followed it killed twenty-five million in four months.23

  • Europe was laid waste by measles after AD 165, by smallpox after AD 251, by bubonic plague after 1348, by syphilis after 1492, by tuberculosis after 1800.24 And those are just the epidemics.

  • The success of the genes that defended you so well in the last generation may be the best of reasons to abandon these same gene combinations in the next. By the time the next generation comes around, the parasites will have surely evolved an answer to the defence that worked best in the last generation.

  • A rabbit running from a fox is running for its life, so it has the greater evolutionary incentive to be fast. The fox is merely after its dinner. True enough, but what about a gazelle running from a cheetah? Whereas foxes eat things other than rabbits, cheetahs eat only gazelles, so a slow cheetah never catches anything and dies. A slow gazelle might never be unlucky enough to meet a cheetah. So the down-side is greater for the cheetah. As Dawkins and Krebs put it, the specialist will usually win the race.

  • Parasites are supreme specialists, but

  • it dies. Gary Larson once drew a cartoon of a flea walking through the hairs on a dog’s back carrying a placard that read: ‘The end of the dog is nigh’: the death of the dog is bad news for the flea, even if the flea hastened it.

  • Sisyphus,

    • Like naranth branthan
  • one ingenious theory holds that sperm are small specifically so that they have no room to carry bacteria with them to infect eggs.33

  • A human embryo indulges in a frenzy of cell division soon after it is fertilized, perhaps to leave behind any viruses and bacteria stuck in one of the compartments.

  • Plants and many insects and amphibians have an additional method, chemical defence: they produce chemicals that are toxic to their pests; some species of pest then evolve ways of breaking down the toxins, and so on; an arms race has begun.

  • Antibiotics are chemicals produced naturally by fungi to kill their rivals: bacteria. But when man began to use antibiotics he found that, with disappointing speed, the bacteria were evolving the ability to resist the antibiotics. There were two startling things about antibiotic resistance in pathogenic bacteria. One, the genes for resistance seemed to jump from one species to another, from harmless gut bacteria to pathogens, by a form of gene transfer not unlike sex. And two, many of the bugs seemed to have the resistance genes already on their chromosomes; it was just a matter of re-inventing the trick of switching them on. The arms race between bacteria and fungi has left many bacteria with the ability to fight antibiotics, an ability they no longer ‘thought they would need’ when inside a human gut.

  • Because they are so short-lived compared with their hosts, parasites can be quicker to evolve and adapt. In about ten years, the genes of the AIDS virus change as much as human genes change in ten million years. For bacteria, thirty minutes can be lifetime. Human beings, whose generations are an eternal thirty years long, are evolutionary tortoises.

  • house mice appear to choose as mates only those house mice that have different histocompatibility genes from their own. They do this by smell. This preference maximizes the variety of genes in mice and makes the young mice more disease-resistant.

  • Just as the rabies virus makes the dog want to bite anything, thus subverting the dog to its own purpose of spreading to another dog, so a gene might make its owner have sex,

  • It is a curious statistical fact that between them all forty-two presidents of the United States have had ninety sons and only sixty-one daughters. A sex ratio of sixty per cent male in such a large sample is markedly different from the population at large, though how it came about nobody can guess – probably by pure chance. Yet presidents are not alone. Royalty, aristocrats and even well-off American settlers have all consistently produced slightly more sons than daughters. So do well-fed opossums, hamsters and coypus and high-ranking spider monkeys. The Trivers–Willard theory links these diverse facts.48

  • If males are polygamous, a successful son can give you far more grandchildren than a successful daughter, and an unsuccessful son will do far worse than an unsuccessful daughter because he will fail to win any mates at all. A son is a high-risk-high-reward reproductive option compared to a daughter.

  • A mother in good condition gives her offspring a good start in life, increasing the chances of her sons winning harems as they mature. A mother in poor condition is likely to produce a feeble son who will fail to mate at all, whereas her daughters can join harems and reproduce even when not in top condition.

  • So you should have sons if you have reason to think they will do well and daughters if you have reason to think they will do poorly – relative to others in the population.49

  • said Trivers and Willard, especially in polygamous animals, parents in good condition probably have male-biased litters of young; parents in poor condition probably have female-biased litters. Initially this was scoffed at as far-fetched conjecture, but gradually it has received grudging respect and empirical support.

  • Consider the case of the Venezuelan opossum, a marsupial that looks like a large rat and lives in burrows. Steve Austad and Mel Sunquist of Harvard were intent on disproving the Trivers–Willard theory. They trapped and marked forty virgin female opossums in their burrows in Venezuela. Then they fed twenty of them each with 125 gram of sardines every two days by leaving the sardines outside the burrows, no doubt to the delight and astonishment of the opossums. Every month thereafter they trapped the animals again, opened their pouches and sexed their babies. Among the two hundred and fifty-six young belonging to the mothers who had not been fed sardines, the ratio of males to females was exactly one to one. Among the two hundred and seventy from mothers who had been fed sardines, the sex ratio was nearly 1.4 to 1. Well-fed opossums are significantly more likely to have sons than poorly fed ones.50

  • Hamsters reared in the laboratory can be made to have female-biased litters by keeping them hungry during adolescence or pregnancy.

  • Among coypus (large, aquatic rodents), females in good condition give birth to male-biased litters; those in poor condition give birth to female-biased litters. In white-tailed deer, older mothers or yearlings in poor condition have female fawns more often than by chance alone. So do rats kept in conditions of stress. But in many ungulates (hoofed animals), stress or poor habitat has the opposite effect, inducing a male-biased sex ratio.51

  • Some of these effects can be easily explained by rival theories. Because males are often bigger than females, male embryos generally grow faster and are more of a strain on the mother. Therefore it pays a hungry hamster or a weak deer to miscarry a male-biased litter and retain a female-biased one. Moreover, proving biased sex ratios at birth is not easy and there have been so many negative results that some scientists maintain the positive ones are merely statistical flukes (if you toss a coin for long enough, sooner or later you will get twenty heads in a row). But neither explanation can address the opossum study and others like it. By the late 1980s, many biologists were convinced that Trivers–Willard was right at least some of the time.52

  • The most intriguing results, however, were those that concerned social status. Tim Clutton-Brock of Cambridge University studied red deer on the island of Rhum off the Scottish coast. He found that the mother’s condition had little effect on the gender of her calves, but her rank within the social group did have an effect. Dominant females were slightly more likely to have sons than daughters.

  • Among baboons, howler monkeys, rhesus macaques and bonnet macaques, the opposite preference prevailed: high-ranking females gave birth to female offspring and low-ranking females give birth to male offspring. In the eighty births to twenty female Kenyan baboons studied by Jeanne Altmann of the University of Chicago, the effect was so pronounced that high-ranking females were twice as likely to have daughters as low-ranking ones. Subsequent studies have come to less clear conclusions and a few scientists believe that the monkey results are explained by chance. But one intriguing hint suggests otherwise.55

  • This may be no accident. In most monkeys (including howlers, baboons and macaques) males leave the troop of their birth and join another at puberty – so-called male exogamy. In spider monkeys the reverse applies: females leave home. If a monkey leaves the troop it is born into, it has no chance to inherit its mother’s rank. Therefore high-ranking females will have young of whatever gender stays at home in order to – pass on the high rank to them. Low-ranking females will have young of whatever gender leaves the troop in order not to saddle the young with low rank. Thus high-ranking howlers, baboons and macaques have daughters; high-ranking spider monkeys have sons.56

  • local-resource competition model.57 High rank leads to a sex bias in favour of the gender that does not leave at puberty. Could it possibly apply to human beings?

  • human society, like ape society but unlike most monkey society, is a female-exogamous patriarchy and sons inherit their father’s (or mother’s) status more than daughters inherit their parents’ status. Therefore, says Trivers–Willard, it would pay high-ranking fathers, or dominant women, or both, to have sons and subordinates to have daughters. Do they? The short answer is that nobody knows.

  • Almost no subject is more steeped in myth and lore than the business of choosing the gender of children. Aristotle and the Talmud both recommended placing the bed on a north–south axis for those wanting boys. Anaxagoras’ belief that lying on the right side during sex would produce a boy was so influential that centuries later some French aristocrats had their left testicles amputated. At least posterity had its revenge on Anaxagoras, a Greek philosopher and client of Pericles. He was killed by a stone dropped by a crow, no doubt a retrospective reincarnation of some future French marquis who cut off his left testicle and had six girls in a row.

  • Among zebra finches, as Nancy Burley of the University of California at Santa Cruz discovered, ‘attractive’ males mated with ‘unattractive’ females usually have more sons than daughters, and vice versa. Attractiveness in this species can be altered by the simple expedient of putting red (attractive) or green (unattractive) bands on the male’s legs, and black (attractive) or light blue (unattractive) on the female’s legs. This makes them more or less desirable to other zebra finches as mates.

  • The Chinese, deprived of the chance to have more than one child, killed more than 250,000 girls after birth between 1979 and 1984.65 In some age groups in China, there are 122 boys for every 100 girls.

  • recent study of clinics in Bombay, of 8,000 abortions, 7,997 were of female foetuses.

  • But it seems a wasteful way

  • There are many well-established natural factors that bias the sex ratio of human offspring, proving that it is at least possible. The most famous is the returning-soldier effect. During and immediately after major wars, more sons are born than usual in the belligerent countries as if to replace the men that died (this would make little sense: the men born after wars will mate with their contemporaries, not with those widowed by the war). Older fathers are more likely to have girls, but older mothers are more likely to have boys. Women with infectious hepatitis or schizophrenia have slightly more daughters than sons. So do women who smoke or drink. So did women who gave birth after the thick London smog of 1952. So do the wives of test pilots, abalone divers, vicars and anaesthetists. In parts of Australia that depend on rainfall for drinking water, there is a clear fall in the proportion of sons born three hundred and twenty days after a heavy storm fills the dams and churns up the mud. Women with multiple sclerosis have more sons as do women who consume small amounts of arsenic.

  • Valerie Grant’s theory suggests a hormonal explanation for the returning-soldier effect: that during wars women adopt more dominant roles, which affects their hormone levels and their tendency to have sons.

  • How the hormones work nobody knows, but it is possible that they change the consistency of the mucus on the cervix, or even that they alter the acidity of the vagina. Putting baking soda in the vagina of a rabbit was proved to affect the sex ratio of its babies as early as 1932.

  • Instead rank determines hormones, which determine the sex ratio of offspring.

  • female infanticide that the British tried and failed to stamp out coincided with relatively high social rank in the distinctly stratified society of nineteenth-century India.

  • In Dickemann’s analysis, dowries are merely a distorted echo of the Trivers-Willard effect in a female-exogamous species: sons inherit the status necessary for successful breeding; daughters have to buy it. If you have no wealth to pass on, use what you have to buy your daughter a good husband.

  • (‘a hen is only an egg’s way of making another egg’),

  • The goal for every female animal is to find a mate with sufficient genetic quality to make a good husband, a good father or a good sire. The goal for every male animal is often to find as many wives as possible, and sometimes to find good mothers and dams, only rarely to find good wives. In 1972 Robert Trivers noticed the reason for this asymmetry, which runs right through the animal kingdom; the rare exceptions to his rule prove why it generally holds. The sex that invests most in rearing the young – by carrying a foetus for nine months in its belly, for example – is the sex that makes least marginal profit from an extra mating. The sex that invests least has time to spare to seek other mates. Therefore, broadly speaking, males invest less and seek quantity of mates, while females invest more and seek quality of mates.2 The result is that males compete for the attention of females, which means that males have both a greater opportunity to leave large numbers of offspring than females and a greater risk of fathering none. Males act as a kind of genetic sieve: only the best males get to breed and the constant reproductive extinction of bad males constantly purges bad genes from the population.3 From time to time, it has been suggested that this is the ‘purpose’ of males, but that commits the fallacy of assuming that evolution designs what is best for the species. The

  • that is usually the way of the world: males seduce, females are seduced.

  • In the 1980s a new version of this theory was adapted to birds, suggesting that colourful birds are the fastest fliers and are flaunting the fact to hawks and other predators: I’m fast, so don’t even think of trying to chase me. When a scientist put stuffed male and female pied flycatchers out on perches in a wood, it was the dull females that were attacked first by hawks, not the colourful males.

  • Cyrano de Bergerac

  • Females choose; their choosiness is inherited; they prefer exaggerated ornaments; exaggerated ornaments are a burden to males. That much is now uncontroversial. Thus far, Darwin was right.

  • Sir Ronald Fisher had suggested then that females need no better reason for preferring long tails than that other females also prefer long tails. At first, such logic sounds suspiciously circular, but that is its beauty. Once most females are choosing to mate with some males rather than others and are using tail length as the criterion – a big once, granted, but we’ll return to that – then any female who bucks the trend and chooses a short-tailed male will have short-tailed sons.

  • Each peahen is on a treadmill and dare not jump off lest she condemn her sons to celibacy.

  • Early nesting females rear more young than late nesting ones and the most vigorous songster or gaudiest dandy tends to catch the early female.

  • butterflies and other insects also indulge in lekking. A lek is a place where males gather in the breeding season, mark out little territories that are clustered together and parade their wares for visiting females. The characteristic of the lek is that one or a few males, usually those that display near its centre, achieve most of the matings. But the central position of a successful male is not the cause of his success so much as the consequence: other males gather around him.

  • The Fisher (sexy-son, good-taste) advocates are those who insist that the reason peahens prefer beautiful males is because they seek heritable beauty itself to pass on to their sons, so that those sons may in turn attract females. The Good-geners (healthy-offspring,

  • good-sense) are those who believe that peahens prefer beautiful males because the beauty is a sign of good genetic qualities – disease resistance, vigour, strength – and that these are the qualities that the females seek to pass on to their children.

  • Their position is that, especially on leks, females choose males according to the gaudiness of their colours, the length of their plumes, the virtuosity of their songs or whatever, because the species is ruled by an arbitrary fashion for preferring beauty that none dares buck.

  • Proving that Fisher’s runaway selection could happen and the ornaments get bigger with ‘ever-increasing speed’ does not prove that it does happen. Computers are not the real world. Nothing but an experiment could satisfy the naturalists: an experiment that demonstrated that the sexiness of sons drove the evolution of an ornament. Such an experiment has never been devised, but those, like me, with a bias towards the Fisherians find several lines of argument fairly persuasive. Look around the world and what do you see? You see that the ornaments we are discussing are nothing if not arbitrary. Peacocks have eyes

  • the phenomenon of copying. If you watch a lek carefully you will see that the females often do not just make their own minds up individually; they follow each other. Sage grouse hens are more likely to mate with a cock who has just mated with another hen. In black grouse, which also lek, the cocks tend to mate several times in a row if at all. A stuffed female black grouse (known in this species as a greyhen), placed in a male’s territory, tends to draw other females to that territory – though not necessarily causing them to mate.29

  • In guppy fish, females that have been allowed to see two males, one of which is already courting a female, subsequently prefer that male to the other, even if the female that was being courted is no longer present.

  • It is hardly surprising to find that the males best at seduction tend to be the best at other things as well; it does not prove that females are seeking good genes for their offspring. They might be avoiding feeble males lest they catch a virus from them. Nor do such observations damage the idea that the most important thing a sexy male can pass on to his sons is his sexiness – the Fisher idea. They merely suggest that he can also pass on other attributes.

  • ‘that she has located a dominant male who is terrific at finding or stealing rare objects and defeating would-be thieves’.

  • the more a peacock’s tail or a bird of paradise’s plumes handicapped the male, the more honest was the signal they sent to the female. She could be assured by the very fact of his survival that the long-tailed male in front of her had been through a trial and passed. He had survived despite being handicapped. The more costly the handicap, the better it would be as a signal of his genetic quality;

  • the weaker the male, the harder it would be to produce or maintain a tail of a given length. And, indeed, experiments on swallows have shown that birds promoted above their station, by being given longer tail streamers than they grew naturally, could not next time around grow as long a tail as before: carrying the extra handicap had taken its toll.

  • That claim has been challenged and much debated, but it seems to hold up. Zuk found the same in a survey of five hundred and twenty-six tropical birds, and others found it to be true of birds of paradise and some species42 of fresh-water fish: the more parasites, the more showy the species.

  • Even among human beings, the more polygamous a society is, the greater its parasite burden,

  • Since then, Pomiankowski has returned to the subject from a different angle, arguing that Fisher and many ornaments are likely to predominate when the cost to females of choosing is cheap; Good-genes will predominate when the cost of choosing is high. Again we reach the same conclusion: peacocks are Fisherian; swallows are Good-geners.51

  • When a man wants to seduce a woman, he does not send her a copy of his bank statement, but a pearl necklace. He does not send her his doctor’s report, but he lets slip that he runs ten miles a week and never gets colds. He does not tell her what degree he got, but he dazzles her with wit. He does not display testaments to how thoughtful he is, but he sends her a bunch of red roses on her birthday. Each gesture has a message: I’m rich, I’m fit, I’m clever, I’m nice.

  • cockerel’s comb is red because of the carotenoid pigments in it. A male guppy fish is rendered orange by carotenoids also, and a house finch’s or a flamingo’s red plumage depends on carotenoids, too. The peculiar thing about carotenoids is that birds and fish cannot synthesize them within their own tissues; they extract them from their food – from fruit or shellfish, or other plants and invertebrates. But their ability to extract carotenoids from their food and deliver it to their tissues is much affected by certain parasites.

  • The size and brightness of such combs may be affected by parasites, but they are effected by hormones. The higher the level of testosterone in the blood of a cockerel, the bigger and brighter will be his comb and wattles. The problem for the cockerel is that the higher his level of testosterone, the greater will be his parasite infestation. The hormone itself seems to lower his resistance to parasites.

  • Once again nobody knows why, but cortisol, the ‘stress’ hormone that is released into the bloodstream during times of emotional crisis, also has a marked effect on the immune system.

  • Cortisol and testosterone are both steroid hormones and they have a remarkably similar molecular structure: of the five biochemical steps needed to make cholesterol into either cortisol or testosterone, only the last two steps are different.

  • This immune effect of testosterone is the reason that men are more susceptible to infectious disease than women, a trend that occurs throughout the animal kingdom.

  • It is as if male animals have a finite sum of energy, which they can spend on testosterone or immunity to disease, but not both at the same time.

  • ‘Males are thus necessarily more vulnerable to disease as they acquire the accoutrements of maleness.’

  • If a woman of twenty or so puts on weight, however, it takes the form largely of fat on the breasts and buttocks; her waist can remain remarkably narrow.

  • for example, fat is inconvenient if it competes for space about the waist with a foetus.

  • A man looking for a wife is likely to be descended from men who found two things attractive (among many others): big breasts, for feeding his children, and wide hips for bearing them. Death during infancy from a mother’s milk shortage would have been common before modern affluence – and still is in some parts of the world. Death of the mother and infant from too narrow a birth canal must also have been common. Birth complications are peculiarly frequent in man, for the obvious reason that his head size at birth has been increasing fast in the past five million years. The only way birth canals kept up (before Julius Caesar’s mother was cut open) was through the selective death of narrow-hipped women. Grant,

  • fat breasts do not produce more milk than lean ones of the same size, and fat hips are no further apart than lean ones of the same bone structure. Low thinks women who gained fat in those places may have deceived men into thinking they had milk-full breasts and wide hip-bones. Men fell for it,

  • The peacock’s tail for vision, the nightingale’s song for hearing, the scent of the musk deer for smell;69 the pheromones of a moth for taste;

  • the ‘morphological exuberance’ of some insect ‘penises’ for touch;

  • As every bird-watcher knows, the beauty of a bird’s song is inversely correlated with the colourfulness of its plumage.

  • The operatic male nightingales, warblers and larks are brown and usually almost indistinguishable from their females.

  • Birds of paradise, pheasants – in which the males are gorgeous, the females dull – are monotonous, simple songsters given to uninspired squawks. Intriguingly, the same pattern holds among the bowerbirds of New Guinea and Australia: the duller the bird, the more elaborate and decorated is its bower.

  • Fish have magnificent colour vision; whereas we use three different types of colour-detecting cell in the eye (red, blue and green), fish have four and birds have up to seven. Compared to the way birds see the world, our lives are monochrome.

  • idiosyncratic

  • The female preference did not evolve: it just is that way.

  • The connection between sex and power is a long one.

  • For a man, women are vehicles that can carry his genes into the next generation. For a woman, men are sources of a vital substance (sperm) that can turn their eggs into embryos. For each gender, the other is a sought-after resource to be exploited. The question is, how? One way to exploit the other gender is to round up as many as possible of them and persuade them to mate with you, then desert them, as bull elephant seals do. The opposite extreme is to find one individual and share all the duties of parenthood equally, as albatrosses do. Every species falls somewhere on that spectrum, with its own characteristic ‘mating system’. Where does humanity fall?

  • There is only one truly polyandrous society on earth, in Tibet, and it consists of women who marry two or more brothers simultaneously in an attempt to put together a family unit that is economically viable in a harsh land where men herd yaks to support women. The junior brother’s ambition is to leave and obtain his own wife, so polyandry is plainly

  • Throughout history powerful men have usually had more than one mate each, even if they have had only one legitimate wife.

  • And in the matter of seduction itself, once more it is the male that is expected to make the first move. Women may flirt, but men pounce.

  • It is a fair bet that Casanova left more descendants than the Whore of Babylon.

  • This fact suggests that a highly polygamous human society represents a victory for men, whereas a monogamous one suggests a victory for women. But this is misleading. A polygamous society represents, primarily, a victory for one or a few men over all other men. Most men in highly polygamous societies are condemned to celibacy because, remember, sex ratios are equal.

  • Donald Symons of the University of California at Santa Barbara has argued that the reason that male homosexuals on average have more sexual partners than male heterosexuals, and many more than female homosexuals, is that male homosexuals are acting out male tendencies or instincts unfettered by those of women.

  • ‘Which woman would not rather be John Kennedy’s third wife, than Bozo the Clown’s first?’ says one (female) evolutionist.

  • He has been agricultural for less than ten thousand. These are mere eyeblinks. For more than a million years before that he was recognizably human and living, mostly in Africa, probably as a hunter-gatherer, or forager,

  • inside the skull of a modern city dweller there resides a brain designed for hunting and gathering in small groups on the African savannah.

  • By 1.6 million years ago, when Homo erectus, the first truly recognized human being, was living in Africa, he was without question the most carnivorous monkey or ape the world had ever known. That much is known from the bones he left at his camp sites. He

  • Our brains grew so big not to make tools but to psychologize each other.

  • From Hannibal to Bill Clinton, men gain power by putting together coalitions of allies. In mankind wealth became a way of putting together such alliances of power.

  • India, high castes practised more female infanticide than low, because there were fewer opportunities to export daughters into still higher castes. In other words, mating was a trade: male power and resources for female reproductive potential.

  • hypothesized that a rich man (or woman) in a polygamous society would tend to leave his money to a son rather than a daughter, because a rich son could give him more grandchildren than a rich daughter.

  • Therefore, the more polygamous a society is, the more likely it will be to show male-biased inheritance. A survey of four hundred societies found overwhelming support for his hypothesis.

  • There is a cautionary tale that scientists tell each other about a man who cuts the legs off a flea to test his theory that fleas’ ears are on their legs. He then tells the flea to jump and it does not, so he concludes that he was right: fleas’ ears are on their legs.

  • were sung about in Sumerian lullabies. The Tang Dynasty emperors of China kept careful records of dates of menstruation and conception in the harem so as to be sure to copulate only with the most fertile concubines. Chinese emperors were also taught to conserve their semen so as to keep up their quota of two women a day, and some even complained of their onerous sexual duties. These harems could hardly have been more carefully designed as breeding machines, dedicated to the spread of emperors’ genes.

  • Betzig’s point is that it is one thing to find that powerful emperors were polygamous, quite another to discover that they each adopted similar measures to enhance their reproductive success within the harem: wet nursing, fertility monitoring, claustration of the concubines, and so on. These are not the measures of men interested in sexual excess. They are the measures of men interested in producing many children.

  • In other words, they always raised one mate above all the others as a ‘queen’. This is characteristic of human polygamous societies. Wherever there are harems, there is a senior wife, treated differently from the others. She is usually noble-born, and, crucially, she alone is allowed to bear legitimate heirs. Solomon had a thousand concubines, and one queen.

  • ‘The charge of being a womanizer stuck, and as an elderly man he is said to have still harboured a passion for deflowering girls – who were collected for him by his wife’. Tiberius’ ‘criminal lusts’ were ‘worthy of an oriental tyrant’ (Tacitus). Caligula ‘made advances to almost every woman of rank in Rome’ (Dio), including his sisters. Even Claudius was pimped for by his wife, who gave him ‘sundry housemaids to lie with’ (Dio). When Nero floated down the Tiber, he ‘had a row of temporary brothels erected on the shore’ (Suetonius). As in the case of China, though not so methodically, breeding seems to have been a principal function of concubines.

  • ‘Ordinary’ Roman nobles kept hundreds of slaves. Yet, while virtually none of the female slaves had jobs around the house, female slaves commanded high prices if sold in youth. Male slaves were usually forced to remain celibate, so why were the Roman nobles buying so many young female slaves? To breed other slaves, say most historians. Yet that should have made pregnant slaves command high prices; they did not. If a slave turned out not to be a virgin, the buyer had a legal case against the seller.

  • There is little doubt that those Roman writers who equate slaves with concubines were telling the truth. The unrestricted sexual availability of slaves ‘is treated as a commonplace in Graeco-Roman literature from Homer on; only modern writers have managed largely to ignore

  • Moreover, Roman nobles freed many of their slaves at suspiciously young ages and with suspiciously large endowments of wealth. This cannot have been an economically sensible decision. Freed slaves became rich and numerous. Narcissus was the richest man of his day. Most freed slaves were born in their masters’ homes, whereas slaves in the mines or on farms were rarely freed.

  • When Betzig turned her attention to medieval Christendom, she discovered that the phenomenon of monogamous marriage and polygamous mating was so entrenched that it required some disinterring. Polygamy became more secret, but it did not expire. In medieval times, the census shows a sex ratio in the countryside that was heavily male-biased because so many women were ‘employed’ in the castles and monasteries. Their jobs were those of serving maids of various kinds but they formed a loose sort of ‘harem’, whose size depended clearly on the wealth and power of the castle’s owner. In some cases, historians and authors were more or less explicit in admitting that castles contained ‘gynoeciums’, where lived the owner’s harem in secluded luxury.

  • Count Baudouin, patron of a literary cleric named Lambert, ‘was buried with twenty-three bastards in attendance as well as ten legitimate daughters and sons’. ‘His bedchamber had access to the servant girls’ quarters, and to the rooms of adolescent girls upstairs. It had access, too, to the warming room, “a veritable incubator for suckling infants”.’ Meanwhile many medieval peasant men were lucky to marry before middle age and had few opportunities for fornication.

  • In 1790, nine mutineers from HMS Bounty landed on Pitcairn along with six male and thirteen female Polynesians. Thousands of miles from the nearest habitation, unknown to the world, they set about building a life on the little island. Notice the imbalance: fifteen men and thirteen women. When the colony was discovered eighteen years later, ten of the women had survived and only one of the men. Of the other men, one had committed suicide, one had died and twelve had been murdered.

  • a village that is too small is likely to be raided for women, but a village that is too large usually breaks up over adultery. Women are the currency and reward of male violence in the Yanomamö.

  • Chagnon now believes that the conventional wisdom – people only fight over scarce resources – misses the point. If resources are scarce, then people fight over them. If not, they do not. ‘Why bother,’ he says, ‘to fight for mongongo nuts when the only point of having mongongo nuts is so that you can have women. Why not fight over women?’ Most human societies, he believes, are not touching some ceiling of resource limitation.

  • Then teach me, Echo, how shall I come by her? Buy her. Jonathan Swift, ‘A Gentle Echo on Woman’

  • The Herod Effect

  • ‘sperm competition theory’.

  • First, women most commonly seek monogamous marriage – even in societies that allow polygamy. Rare exceptions notwithstanding, they want to choose carefully and then, so long as he remains worthy, monopolize a man for life, gain his assistance in rearing the children and perhaps even die with him. Second, women do not seek sexual variety per se. There are exceptions, of course, but fictional and real women regularly deny that nymphomania holds any attractions for them and there is no reason we should disbelieve them. The temptress interested in a one-night stand with a man whose name she does not know is a fantasy fed by male pornography. Lesbians, free of constraints imposed by male nature, do not suddenly indulge in sexual promiscuity; on the contrary, they are remarkably monogamous. None of this is surprising: female animals gain little from sexual opportunism, for their reproductive ability is limited not by how many males they mate with but by how long it takes to bear offspring. In this respect men and women are very different.

  • But third, women are sometimes unfaithful. Not all adultery is caused by men. Though she may rarely or never be interested in casual sex with a male prostitute or stranger, a woman, in life as in soap opera, is perfectly capable of accepting or provoking an offer of an affair with one man whom she knows, even if she is ‘happily’ married at the time.

  • In Short, the bigger the testicles, the more polygamous the females.12

  • some male damsel flies use their penis to scoop out sperm that was there first; male dogs and Australian hopping mice both ‘lock’ their penis into the female after copulation and cannot free it for some time, thus preventing others having a go; male human beings seem to produce large numbers of defective ‘kamikaze’ sperm that form a sort of plug that closes the vaginal door to later entrants.

  • This theory is supported by the facts: females always choose more dominant, older, or more ‘attractive’ (i.e., ornamented with longer tail feathers) lovers than their husbands; they do not have affairs with bachelors (i.e., presumably, those that have been rejected by other females), but with other females’ husbands; and they sometimes incite competitions between potential lovers and choose the winners.

  • So he speculates that the sexual division of labour, the institution of child-rearing marriages and the invention of language – three of the most fundamental human characteristics that we share with no other ape – all depended on each other.

  • Although women are more likely to initiate sex, masturbate, have an affair with a lover, or be accompanied by their husband on the day of ovulation than on other days,

  • research shows that people are strangely more apt to say of a baby, ‘he (or she) looks just like his father’ than to say ‘he (or she) looks just like his mother’ – and that it is the mother’s relatives who are most likely to say this.

  • from a parent is not unique to man. There are

  • Indeed, in more stratified societies, the poor often favour their daughters over their sons. But this is not because of certainty of paternity, but because poor daughters are more likely to breed than poor sons.

  • Just like meadow voles, men are better at spatial tasks than women. When asked to compare the shapes of two objects seen from different angles, and judge whether they are the same shape, or to judge whether two glasses of different shapes are equally full, or any such task that involves spatial judgement, men generally do better than women. Polygamy and spatial skills seem to go together in several species.

  • When people are asked to rotate a diagram of an object mentally to see if it is the same as another object, only about one in four women score as highly as the average man.

  • that, during the Pleistocene period, when early man was an African hunter-gatherer for a million years or more, men were the hunters. So men needed superior spatial skills to throw weapons at moving targets, to make tools, to find their way home to camp after a long trek, and so on.

  • On every measure of object memory and location memory, the women students did sixty to seventy per cent better than the men. The old jokes about women noticing things and men losing things about the house and having to ask their wives are true.

  • just as the social and verbal skills of women begin to exceed those of men at puberty.

  • When a family in a car gets lost, the woman wants to stop and ask the way, while the man persists in trying to find his way by map or landmarks. So pervasive is this cliché that there must be some truth in it. And it fits with what we know of the sexes. To a man, stopping to ask the way is an admission of defeat, something status-conscious males avoid at all costs. To a woman, it is common sense and plays on her strengths in social skills.

  • There is no evidence for genes for different brains, but there is ample evidence for genes for altering brains in response to male hormones (for reasons of historical accident, the ‘normal brain’ is female unless masculinized). So the mental differences between men and women are caused by genes that respond to testosterone.

  • Its concentration determines aggressiveness so exactly that in birds with reversed sex roles such as phalaropes, and in female-dominated hyaena clans, it is the females that have higher levels of testosterone in the blood.

  • Inject all pregnant women with the right dose of hormones and the result would be men and women with normal bodies, but identical feminine brains. War, rape, boxing, motor racing, pornography, beer and hamburgers would soon be distant memories. A feminist paradise would have arrived.

  • ‘Education is almost a conspiracy against the aptitudes and inclinations of a school boy’, wrote psychologist Dianne McGuinness, a sentiment to which almost every man with a memory of school will raise a hearty cry of assent.

  • But another fact begins to emerge at school. Girls are simply better at linguistic forms of learning, boys at mathematical and some spatial skills. Boys are more abstract, girls more literal. Boys with an extra X chromosome (XXY instead of the normal XY) are much more verbal than other boys. Girls with Turner’s syndrome (no ovaries) are even worse at spatial tasks than other girls, but just as good at verbal ones. Girls who were exposed to male hormones in the womb are better at spatial tasks. Boys who were exposed to female hormones are worse at spatial tasks. These facts have been first disputed and then actively suppressed by the educational establishment, which continues to insist that there are no differences in learning ability between boys and girls. According to one researcher, such suppression has done both boys and girls far more harm than good.18

  • Yet, at five, the testosterone levels in the average boy are identical to those of the average girl, and a fraction of what they were at birth. The pulse of testosterone in the womb is a distant memory, and there will be little difference between the sexes in testosterone levels until the age of eleven or twelve.

  • A boy of eleven is far more similar to a girl of the same age than he has been before or will be again. He is academically her equal for the first time and his interests are not so far apart.

  • Intriguingly, men who were conceived and born in periods of great stress, such as towards the end of the Second World War in Germany, are more often gay than men born at other times. (The stress hormone, cortisol, is made from the same progenitor as testosterone; perhaps it uses up the raw material, leaving less to be made into testosterone.)

  • ‘Our repressed impulses are every bit as human as the forces that repress them.’

  • When watching pornography, men and women are both interested in the women actors. But porn is designed for, marketed to, and sought out by, men not women.

  • There is also good evidence that the gene is inherited from the mother and not from the father.1 How could such a gene survive, given that gay men generally do not have children? There are two possible answers. One is that the gene is good for female fertility when in women, to the same extent that it is bad for male infertility when in men.

  • If new theories are right, the evolution of man’s big head was the result of a Red Queen sexual contest between individuals of the same gender.

  • She can learn that the word for a cow is vache, or cow or any other word. And likewise, in knowing that she must blink or duck when a ball approaches her face at speed, a child need have no plasticity at all. To have to learn such a reflex would be painful. So the blink reflex is prepared, and the vocabulary store in her brain is plastic.

  • position of the apocryphal explorer who points at a never-before-seen animal and says to hi local guide: ‘What’s that?’ The guide replies: ‘Kangaroo’, which means, in his own language, ‘I don’t know.’

  • almost all linguists now agree with Noam Chomsky that there is a ‘deep structure’ that is universal to all languages and it is programmed into the brain rather than learnt.

  • Just because language is acquired after birth does not mean that it is cultural. Teeth are also acquired after birth.

  • Infant New Yorkers find it far easier to acquire a fear of snakes than of cars, despite the far greater danger posed by the latter: their brains are simply predisposed to fear snakes. Fearing snakes and assuming that

  • Nor is, for example, the unwillingness of adults to have sex with people with whom they have lived as children

  • The astonishing symbiotic relationship between the African honeyguide bird and people, in which the bird leads a man to a bees’ nest and then eats what remains of the honey when he leaves, depends on the fact that people know because they have been told that honeyguides lead them to honey.

  • and whether to eat centipedes and snakes. Chimpanzees actually seek out a special plant whose leaves can cure them of worm infections, and they have cultural traditions about how to crack nuts. Any animal whose generations overlap and which lives in groups can accumulate a store of knowledge of natural history that is passed on merely by imitation.

  • ‘neoteny’ – the retention of juvenile features into adult

  • ‘Man is born and remains more immature and for a longer period than any other animal,’

  • Mankind is not the learning ape, he is the clever ape with more instincts more open to experience.

  • Humphrey began an essay on the topic with the story of how Henry Ford once asked his representatives to find out which parts of the Model T never went wrong. They came back with the answer that the kingpin had never gone wrong; so Ford ordered it made to an inferior specification to save money. ‘Nature,’ wrote Humphrey, ‘is surely at least as careful an economist as Henry Ford.’

  • Indeed novelists themselves saw this first. In George Eliot’s Felix Holt, the Radical, she gives a concise summary of the Alexander-Humphrey theory: Fancy what a game of chess would be if all the chessmen had passions and intellects, more or less small and cunning; if you were not only uncertain about your adversary’s men, but a little uncertain also about your own … You would be especially likely to be beaten, if you depended arrogantly on your mathematical imagination, and regarded your passionate pieces with contempt. Yet this imaginary chess is easy compared with a game a man has to play against his fellow-men with other fellow-men for instruments. The Alexander–Humphrey theory, which is widely known as the Machiavellian hypothesis,41

  • In 1978, Richard Dawkins and John Krebs pointed out that animals use communication principally to manipulate each other, rather than transfer information. A bird sings long and eloquently to persuade a female to mate with him, or a rival to keep clear of his territory. If he were merely passing on information, he need not make the song so elaborate. Animals’ communication, said Dawkins and Krebs, is more like human advertising than like airline timetables. Even the most mutually beneficial communication, like that between a mother and a baby, is pure manipulation, as every mother who has been woken in the night by a desperate sounding infant that merely wants company knows. Once scientists had begun thinking in this way, they looked at animal social life in an entirely new light.

  • It consists of four cards placed on the table. Each card has a letter on one side and a number on the other. At present the cards read as follows: D; F; 3; 7. Your task is to turn over only those cards that you need to in order to prove the following rule to be true or false: if a card has a D on one side, then it has a 3 on the other. When presented with this test, less than one-quarter of Stanford students got it right: an average performance. (The right answer, by the way, is D and 7.) But it has been known for years that people are much better at the Wason test if it is presented differently. For example, the problem can be set as follows: ‘You are a bouncer in a Boston bar and you will lose your job unless you enforce the following law: if a person is drinking beer then he must be over twenty years old.’ The cards now read: drinking beer; drinking Coke; twenty-five years old; sixteen years old. Now three-quarters of students get the right answer by turning over the cards marked drinking beer and sixteen years old. But the problem is logically identical to the first one. Perhaps the more familiar context of the Boston bar is what helps people do better. But other equally familiar examples elicit poor performance. The secret of why some Wason tests are easier than others has proved to be one of psychology’s enduring enigmas. What Cosmides and Gigerenzer have done is solve the enigma. It is simply this: if the law to be enforced is not a social contract, the problem is difficult – however simple its logic; but if it is a social contract, like the drinking-beer example, then it is easy.

  • one of Gigerenzer’s experiments, people were good at enforcing the rule, ‘If you take a pension then you must have worked here ten years’, by wanting to know what was on the back of the cards – ‘worked here eight years’ and ‘got a pension’ – so long as they were told they were the employer. But if told they were an employee and still set the same rule, they turned over the cards – ‘worked here twelve years’ and ‘did not get a pension’ – as if looking for cheating employers even though the logic clearly implies that cheating employers are not infringing the rule.

  • Through a long series of experiments Cosmides and Gigerenzer proved that people are simply not treating the puzzles as pieces of logic at all. They are treating them as social contracts and looking for cheats. The human mind may not be much suited to logic at all, they conclude, but is well suited to judging the fairness of social bargains and the sincerity of social offers.

  • Richard Byrne and Andrew Whiten of the University of St Andrews studied baboons in East Africa and witnessed an incident in which Paul, a young baboon, saw an adult female, Mel, find a large root. He looked around and then gave a sharp cry. The call summoned Paul’s mother, who ‘assumed’ that Mel had just stolen the food from her young or threatened him in some way, and chased Mel away. Paul ate the root. This piece of social manipulation by the young baboon required some intelligence: a knowledge that its call would bring its mother, a guess at what the mother would ‘assume’ had happened, and a prediction that it would lead to Paul getting the food.

  • Byrne and Whiten went on to suggest that the habit of calculated deception is common in mankind, occasional in chimpanzees, rare in baboons and virtually unknown in other animals. Deceiving and detecting deception would then be the primary reason for intelligence. They suggest that the great apes acquired a unique ability to imagine alternative possible worlds as a means to deception.

  • Robert Trivers has argued that to deceive others well, an animal must deceive itself, and that self-deception’s hallmark is a biased system of transfer from the conscious to the unconscious mind. Deception is therefore the reason for the invention of the subconscious.

  • I suggest that the neocortex is not primarily or exclusively a device for tool-making, bipedal walking, fire-using, warfare, hunting, gathering, or avoiding savanna predators. None of these postulated functions alone can explain its explosive development in our lineage and not in other closely related species … The neocortex is largely a courtship device to attract and retain sexual mates: its specific evolutionary function is to stimulate and entertain other people, and to assess the stimulation attempts of others.51

  • ‘Just as the peahen is satisfied with nothing less than a visually brilliant display of peacock plumage, I postulate that hominid males and females became satisfied with nothing less than psychologically brilliant, fascinating, articulate, entertaining companions.’

  • Miller suggests that to keep a husband around for long enough to help in raising children, women would have needed to be as varied and creative in their behaviour as possible, which he calls the Scheherazade effect after the Arabian story teller who entranced the Sultan with one thousand and one tales so that he did not abandon her (and execute her) for another courtesan.

  • The same would have applied to males who wanted to attract females, which Miller calls the Dionysus effect after the Greek god of dance, music, intoxication and seduction. He might also have called it the Mick Jagger effect; he admitted to me one day that he could not understand what made strutting, middle-aged rock stars so attractive to women. In this respect, Don Symons noted that tribal chiefs are both gifted orators and highly polygamous men.

  • A human infant is born helpless and premature. If it were as advanced at birth as an ape it would be twenty-one months in the womb.

  • If men began selecting mates that appeared youthful, then any gene that slowed the rate of development of adult characteristics in a woman would make her more attractive at a given age than a rival. Consequently, she would leave more descendants, who would inherit the same gene. Any neoteny gene would give the appearance of youthfulness. Neoteny, in other words, could be a consequence of sexual selection, and since neoteny is credited with increasing our intelligence (by enlarging the brain size at adulthood), it is to sexual selection that we should attribute our great intelligence. The idea is hard to grasp at first, so a thought experiment may help. Imagine two primeval women, one of whom develops at the normal rate and the other of whom has an extra neoteny gene, so that she has a hairless body and is large brained, small jawed, late maturing and long lived. At the age of twenty-five, both are widowed; each has had one child by their first husband. The men in the tribe have a preference for young women and twenty-five is not young, so neither stands much chance of getting a second husband. But there is one man who cannot find a wife. Given the alternatives, he chooses the younger-looking woman. She goes on to have three more children, while her rival barely manages to rear the one she already had.

  • Christopher Badcock of the London School of Economics, who unusually combines an interest in evolution and an interest in Freud, has proposed a similar idea. He suggested that neotenous (or, as he calls it, paedomorphic) traits were favoured by female choice, rather than male choice. Younger males, he suggests, made more co-operative hunters and therefore females that wanted meat picked younger-looking men. The principle is the same: neotenous development is a consequence of a preference for it in one sex.59

  • Indeed, once these advantages became clear, men who were especially fussy about picking youthful-looking women would be most successful because they would sometimes be picking neotenous, big-brained women and therefore would have more intelligent children. But it does suggest an escape from the question: why did it not happen to baboons?

  • However, Miller’s sexual selection idea suffers from a near-fatal flaw. Remember it presupposes sexual choosiness by one or other sex. But what caused that choosiness? Presumably, the cause was the fact that men took part in parental care, which gave women an incentive to confine probable paternity to one man and gave men an incentive to enter into a long-term relationship so long as they could be certain of paternity. Why then did men take part in parental care? Because by doing so they could increase the chances of rearing a child more than by trying to seek new partners. The reason for this was that children, unusual for ape infants, took a long time to mature and men could help their wives during child-rearing by hunting meat for them. Why did they take a long time to mature? Because they had big heads! The argument is circular.

  • Know then thyself, presume not God to scan, The proper study of Mankind is Man. Plac’d on this isthmus of a middle state, A Being darkly wise, and rudely great: With too much knowledge for the Sceptic side, With too much weakness for the Stoic’s pride, He hangs between; in doubt to act, or rest; In doubt to deem himself a God, or Beast; In doubt his Mind or Body to prefer; Born but to die, and reas’ning but to err; Alike in ignorance, his reason such, Whether he thinks too little, or too much. Alexander Pope, from An Essay on Man

  • Mankind is a self-domesticated animal; a mammal; an ape; a social ape; an ape in which the male takes the initiative in courtship and females usually leave the society of their birth; an ape in which men are predators, women herbivorous foragers; an ape in which males are relatively hierarchical, females relatively egalitarian; an ape in which males contribute unusually large amounts of investment in the upbringing of their offspring by provisioning their mates and their children with food, protection and company; an ape in which monogamous pair bonds are the rule, but many males have affairs and occasional males achieve polygamy; an ape in which females mated to low-ranking males often cuckold their husbands in order to gain access to the genes of higher-ranking males; an ape that has been subject to unusually intense mutual sexual selection, so that many of the features of the female body (lips, breasts, waists) and the mind of both sexes (songs, competitive ambition, status seeking) are designed for use in competition for mates; an ape that has developed an extraordinary range of new instincts to learn by association, to communicate by speech and to pass on traditions. But still an ape.