How the human species changed, within a short time, from just another species of big mammal to a world conqueror; and how we acquired the capacity to reverse all that progress overnight.


~ Just Another Species of Big Mammal
~ A Tale of Three Chimps
~ The Great Leap Forward
~ The Evolution of Human Sexuality
~ The Origin of Human Races
~ Why Do We Grow Old and Die?
~ Uniquely Human
~ Animal Origins of Art
~ Alone in a Crowded Universe
~ The Last First Contacts
~ World Conquerors
~ The Golden Age That Never Was
~ (External Resources)


It is obvious that humans are unlike all animals. It is also obvious that we are a species of big mammal, down to the minutest details of our anatomy and out molecules. That contradiction is the most fascinating feature of the human species. It is familiar, but we still have difficulty grasping how it came to be and what it means.
On the one hand, between ourselves and all other species lies a seemingly unbridgeable gulf that we acknowledge by defining a category called 'animals'. It implies that we consider centipedes, chimpanzees, and clams to share decisive features with each other but not with us, and to lack features restricted to us.
Among these characteristics unqiue to us are our abilities to talk, write, and build complex machines. We depend completely on tools, not just on our bare hands, to make a living. Most of us wear clothes and enjoy art, and many of us believe in a religion. We are distributed over the whole Earth, command much of its energy and production, and are beginning to expand into the ocean depths and into space. We are also unique in our darker attributes, including genocide, delight in torture, addictions to toxic drugs, and extermination of other species by the thousands. While a few animal species have one or two of these attributes in rudimentary form (like tool use), we still far eclipse animals even in those respects.
Thus, for practical and legal purposes, humans are not animals. On the other hand, we obviously are animals, with the usual animal body parts, molecules and genes. It is even clear what particular type of animal we are. Externally, we are so similar to chimpanzees... just imagine taking some normal people, stripping off their clothes, taking away all their other possessions, depriving them of the power of speech, and reducing them to grunting, without changing their anatomy at all. Put them in a cage in the zoo next to the chimp cages, and let the rest of us clothed and talking people visit the zoo. Those speechless caged people would be seen for what we all really are: a chimp that has little hair and walks upright. A zoologist from outer space would immediately classify us as just a third species of chimpanzee, along with the pygmy chimp of Zaire and the common chimp of the rest of tropical Africa.

Molecular studies over the last half a dozen years have shown that we continue to share over 98% of our genes with the other two chimps. The overall genetic distance between us and chimps is even smaller than the distance between such closely related bird species as red-eyed and white-eyed vireos, or willow warblers and chiffchaffs. So we still carry most of our old biological baggage with us.
Since Darwin's time, fossilized bones of hundreds of creatures variously intermediate between apes and modern humans have been discovered, making it impossible for a reasonable person to deny the overwhelming evidence. What once seemed absurd - our evolution from apes - actually happened.
Yet the discoveries of many missing links have only made the problem more fascinating, without fully solving it. The few bits of new baggage we acquired - the 2% of our genes that differ from those of chimps - must have been responsible for all our seemingly unique properties. We underwent some small changes with big consequences rather quickly and recently in our evolutionary history.
In fact, as recently as 100,000 years ago that zoologist from outer space would have viewed us as just one more species of big mammal. Granted, we had a couple of curious behavioural habits, notably our control of fire and our dependence on tools, but those habits would have seemed no more curious to the extraterrestrial visitor than would the habits of beavers and bowerbirds. Somehow, within a few tens of thousands of years (a tiny fraction of our species' separate history) we had begun to demonstrate the qualities that makes us unique and fragile.
What were those few key ingredients that made us human? Since our unique properties appeared so recently and involved so few changes, those properties or at least their precursors must already be present in animals. What are those animal precursors of art and languages, of genocide and drug abuse?
Our unique abilities have been responsible for our present biological success as a species. No other large animal is native to all the continents, or breeds in all habitats from deserts and the Arctic to tropical rainforests. No large wild animal rivals us in numbers. But among our unique qualities are two that now jeopardise our existence: our propensities to kill each other and to destroy our environment.
Of course, both propensities occur in other species: lions and many other animals kill their own kind, while elephants and others damage their environment. However, these propensities are much more threatening in us than in other animals because of our technological power and exploding numbers.


Humans and apes are more closely related to each other than either are to monkeys. The chimpanzees' closest relative is not the gorilla but the human. Humans differ from both common chimps and pygmy chimps in about 1.6% of their (our) DNA, and share 98.4%. Gorillas differ somewhat more, by about 2.3%, from us and both of the chimps. The human and 'other chimp' evolutionary lines diverged around 6-8 million years ago.
Our important visible distinctions from the other chimps - our upright posture, large brains, ability to speak, sparse body hair, and peculiar sex lives - must be concentrated in a mere 1.6% of our genes.

What do these results imply about our position in the animal kingdom? Biologists classify living things in hierarchial categories, each less distinct than the next: subspecies, species, genus, family, superfamily, order, class, and phylum. The Encyclopedia Britannia and all the biology texts on my shelf say that humans and apes belong to the same order, called Primates, and the same superfamily, called Hominoidea, but to separate families, called Hominidae and Pongidae.
However another school of taxonomy, called cladistics, argues that classification should be objective and uniform, based on genetic distance or times of divergence. All taxonomists agree now that red-eyed and white-eyed Vireos belong to together in the genus Vireo, willow warblers and chiffchaffs in the genus Phylloscopus, the various species of gibbons in the genus Hylobates. Yet the members of each of these pairs of species are genetically more distant from each other than are humans from the other two chimpanzees, and diverged longer ago.
On this basis, then, humans do no constitute a distinct family, nor even a distinct genus, but belong in the same genus as common and pygmy chimps.
Since our genus name Homo was proposed first, it takes priority, by the rules of nomenclature, over the genus name Pan coined for the 'other chimps'. Thus there are not one but three species of genus Homo on Earth today: the common chimpanzee, Homo troglodytes; the pygmy chimpanzee, Homo paniscus; and the third chimpanzee or human chimpanzee, Homo sapiens.

While scientists understand well the function of numerous genes that specify known individual proteins, we know much less about the function of genes involved in more complex determinations of traits, such as most behavioural features. It would be absurd to think that human hallmarks such as art, language, or aggression depend on a single gene. Behavioural differences among individual humans are obviously subject to enormous environmental influences, and what role genes play in such individual differences is a controversial question. However, for those consistent behavioural differences between chimps and humans, genetic differences are likely to be involved in those species' differences, even though we cannot yet specify the genes responsible.
For instance, the ability of humans but not chimps to speak surely depends on differences in genes specifying the anatomy of the voice box and the wiring of the brain. A young chimp brought up in a psychologist's home along with the psychologist's human baby of the same age still continued to look like a chimp and did not learn to talk or walk erect. But whether an individual human grows up to be fluent in English or Korean is independent of genes and dependent solely on its childhood linguistic environment, as proved by the linguistic attainments of Korean infants adopted by English-speaking parents.


Our lineage diverged from that of apes millions of years ago. For most of that time, we have remained little more than glorified chimpanzees in the way we have made our living. As recently as 40,000 years ago, Western Europe was still occupied by Neanderthals, primitive beings for whom art and progress scarcely existed. Then there was an abrupt change, as anatomically modern people appeared in Europe, bringing with them art, musical instruments, lamps, trade and progress. Within a short time, the Neanderthals were gone. Insofar as there was any single point in time when we could be said to have become human, it was at the time of that great leap forward. What happened at that magic moment in evolution?
Like some other scientists who have speculated about this question, I can think of only one pluasible answer : the anatomical basis for spoken complex language.

Today we take cultural differences among people inhabiting different areas for granted. Every human population alive today has its characteristic house-style, implements, and art. No such cultural variation is apparent for Neanderthals, whose tools look much the same whether they come from Russia or France.
We also take cultural progress with time for granted. The wares from a Roman villa, medieval castle, and modern apartment differ obviously. But Neanderthal tools had no variation in either time or space to suggest that most human of characteristics, innovation.
The most important innovation that came with our rise to humanity is the capacity for innovation itself. To us today, who cannot picture a world in which Nigerians and Latvians in 1991 have virtually the same possessions as each other and as the Romans in 50 BC, innovation is utterly natural. To Neanderthals, it was evidently unthinkable.

New Guinea material culture was until recently primitive (that is, stone age) for historical reasons, but New Guineans are fully modern humans. New Guineans whose fathers lived in the Stone Age now pilot aeroplanes, operate computers, and govern a modern state. If we could carry ourselves back 40,000 years in a time machine, I expect that we would find Cro-Magnons to be equally modern people, capable of learning to fly a jet plane.

What happened when invading Cro-Magnons met the resident Neanderthals in Europe? We can be certain only of the end result : within a short time, no more Neanderthals. I guess that Cro-Magnon diseases, murders and displacements did in the Neanderthals. It may at first seem paradoxical that Cro-Magnons prevailed over the far more muscular Neanderthals, but weaponry rather than strength would have been decisive. Similarly, its not gorillas that are now threatening to exterminate humans in Central Africa, but vice versa. People with huge muscles require lots of food, and they therefore gain no advantage if slimmer, smarter people can use tools to do the same work.

Until the Great Leap Forward, human culture had developed at a snail's pace for millions of years, That pace was dictated by the slow rate of genetic change. After the Leap, cultural development no longer depended on genetic change. Despite negligible changes in our anatomy, there has been far more cultural evolution in the past 40,000 years than in the million of years before.
Had a visitor from outer space come to the Earth in Neanderthal times, humans would not have stood out as unique among the world's species.


Human pairing is more or less monogamous in most modern political states, but is 'mildly polygynous' among most surviving hunter-gatherer bands, which are better models for how mankind lived over the last million years. By 'mildly polygynous' I mean that most hunter-gatherer men can support only a single family, but a few powerful men have several wives.

Monogamy is essential for the survival and education of human offspring. That's because our elaborate, tool-dependent methods of obtaining food make weaned human infants incompetent to feed themselves. Our infants first require a long period of food provisioning, training, and protection; an investment much more taxing than that facing the ape mother. Human babies continue to have all food brought to them by their parents even after weaning, whereas weaned apes gather their own food. Like seagulls but unlike apes or most other mammals, we live in dense breeding colonies of monogamous couples, some of whom also pursue extramarital sex.

The social system we evolved to accomodate our un-apelike food habits seems utterly normal to us, but is bizarre by ape standards and is virtually unique among mammals. Our peculiar societies instead have their closest parallels in colonies of seabirds, like gulls and penguins, which also consist of male/female pairs.

Pursuit of extramarital sex is obviously greatly influenced by each individual's particular upbringing and by the norms of the society in which the individual lives. Despite all that cultural influence, we are left with having to explain the facts that both the institution of marriage and the occurence of extramarital sex have been reported from all human societies : but that extramarital sex is unknown in gibbons, although they do practise 'marriage'; and the question of extramarital sex is meaningless to chimps because they do not practise 'marriage' (that is, lasting male/female pairing to rear offspring).

This social organization shapes the bodies of men and women. Take first the fact that adult men are slighly bigger than similarly aged women (about 8% taller and 20% heavier on average). A zoologist from outer space would take one look at my 5ft8 wife next to me (5ft10), and would instantly guess that we belonged to a mildly polygynous species.

If a man could recognize signs of ovulation, he could use that knowledge to fertilize his wife by copulating with her only while she is ovulating. He could then safely neglect her the rest of the time and go off and philander, secure in the knowledge that the wife left behind was unreceptive.
Concealed ovulation cements the bonds between a particular man and woman, thereby laying the foundations for the human family. A woman remains sexually attractive and receptive so she can satisfy a man sexually all the time, bond him to her, and reward him for help in rearing her baby.

Our concealed ovulation, constant receptivity, and brief fertile period in each menstrual cycle ensure that most copulations by humans are at the wrong time for conception. Even young newlyweds who omit contraception and make love at maximum frequency have only a 28% probability of conception in each menstrual cycle. Whatever the main biological function of human copulation, it is not conception, which is just an occasional by-product.
One of the most ironic tragedies of this is the Catholic Church's claim that human copulation has conception as its natural purpose, and that the rhythm method is the only proper means of birth control. The rhythm method would be terrific for gorillas and most other mammal species, but not for us. In no species besides humans has the purpose of copulation become so unsuited to copulation.

In the 1940s an American doctor studied the genetics of human blood groups, which we acquire only be inheritance. He collected blood samples from 1,000 newborn babies and their mothers and fathers. To his shock, the blood groups revealed nearly 10% of those babies to be the fruits of adultery. Absence of a blood group from both its mother (there could be no question of mistaken maternity) and father shows conclusively that the baby had been sired by some other man, extramaritally. The true incidence of extramarital sex must have been considerably higher than 10%, since most bouts of intercourse do not result in conception. it is clear that extramarital sex is an integral, albeit unoffical, part of the human mating system.

Yet, throughout history, adultery has had few rivals as a cause of human murder and human misery. It is impossible not to be revolted at the sadistic institutions by which societies have attempted to deal with extramarital sex - virtual imprisonment of women, female circumcision, infibulation. These behavioural habits are unique to the human species, defining humanity as much as does the invention of the alphabet. More exactly, they are new means to the old evolutionary goal of males promoting their genes. Some of the other means to this goal are ancient ones shared with many animals, including jealous murder, rape, infanticide, inter-group warfare, and adultery itself.
The role of sexual jealousy as one of the commenest causes of homicide emerges from studies in many American cities and in many other countries. Until the formation of centralized political states provided soldiers with loftier motives, sexual jealousy also loomed large in human history as a cause of war. It was the seduction (abduction,rape) by Paris of Menelaus's wife Helen that provoked the Trojan War. In the modern new Guinean highlands, only disputes over ownership of pigs rival disputes over sex in triggering wars.

The man who sires a baby by one woman is biologically capable of siring a baby by another women the same day. For women, however, the minimum effort consists of copulation plus pregnancy plus (throughout most of human history) several years spent nursing. Thus a man can potentially sire far more offspring than a woman. The record lifetime number of offspring for a man is 888, sired by Emperor Moulay Ismail the Bloodthirsty of Morocco, while the corresponding record for a woman is only 69 (a 19th century Moscow woman specializing in triplets). Few women have topped 20 children, whearas some men easily do so in polygynous societies. Among the polygynous Tenne people of Sierra Leone, a man's average number of children increases from 1.7 to 7 as his number of wives increases from one to five.

The other sexual asymmetry relevant to the best game strategy involves confidence that one really is the biological parent of one's offspring. Barring a switch of babies in the nursery, women cannot be cuckolded, they see their baby emerge from their bodies. An extreme solution to this simple asymmetry is the one formerly adopted by southern India's Nayar society. Among the Nayar, women freely took many lovers simultaneously, and husbands accordingly had no confidence in paternity. To make the best of a bad lot, a Nayar man did not live with his wife or care for his supposed children, but he instead lived with his sisters and cared for his sisters' children. At least, those nieces and nephews were sure to share 1/4 of his genes.

We tend to marry someone who looks like us. But, the men who look most similar to a woman are the men who share half of her genes - her father or brother. Yet most of us obey the incest taboo. We learn, however unconsciously, between the age of birth and six, that our intimate childhood associates from that period (normally our closest relatives) are ineligible as sex partners when we become mature.
The reason we tend to resemble our mates is that many of us are looking for someone who reminds us of our parent or sibling of the opposite sex, who in turn resembles us. As children, we have already begun to develop our search image of a future sex partner, and that image is heavily influenced by the people of the opposite sex whom we see most often - for most of us that is our mother (or father) and sister (or brother), plus close childhood friends.


Natural selection surely explains some geographic variation in humans. Many black Africans, but no Swedes have the sickle-cell haemoglobin gene, because the gene protects against malaria, a tropical disease that would otherwise kill many Africans. Other localized human traits that surely evolved through natural selection include the big chests of Andean Indians (good for extracting oxygen from thin air at high altitudes), the compact shapes of Eskimos (good for conserving heat), the slender shapes of southern Sudanese (good for losing heat), and the slit-like eyes of northern Asians (good for protecting eyes against cold). Do freckles and red hair help Irishmen catch leprechauns?
Can natural selection similarly explain the racial differences that we think of first, those in skin colour, eye colour and hair? If so, one might expect that the same trait (for instance, blue eyes) would reappear in different parts of the world with similar climates.
However, the heaviest objection to any theory based on natural selection is that the association between dark skins and sunny climates is a very imperfect one. No American Indians have black skins, not even in the sunniest parts of the New World.
Facts such as these were what made Darwin despair of imputing human racial variation to his own concept of natural selection. Dawrin came up with a theory that he preferred instead, and termed it sexual selection.


Slow aging is crucial to the human lifestyle because the latter depends on transmitted information. Until the invention of writing, old people acted as repositories of that transmitted information and experience, just as they continue to do in tribal societies today. Under hunter-gatherer conditions, the knowledge possessed by even one person over the age of 70 could spell the difference between survival and starvation or defeat for a whole clan. Thus, our long lifespan was important for our rise from animal to human status.
Our ability to survive to a ripe old age depended ultimately upon advances in culture and technology. It is easier to defend yourself against a lion if you are carrying a spear than just a hand-held stone. However, advances in culture and technology alone would not have been enough, unless our bodies had become redesigned to last longer. No caged ape in a zoo, enjoying all the benefits of modern human technology and veterinary care, reaches 80. Our biology became remoulded to the increased life-expectancy that our cultural advances made possible. Around the time of the Great Leap Forward our biology must have changed so that we aged more slowly. That may even have been the time when menopause, the concomitant of aging that paradoxically functions to let women live longer, evolved.

The way in which scientists think about aging depends on whether they are interested in so-called proximate explanations or ultimate explanations. To appreciate this difference, consider the question, 'Why do skunks smell bad?' A chemist or molecular biologist would answer :
'Its because skunks secrete chemical compounds with certain molecular structures. Those particular chemicals would smell bad no matter what the biological function of their bad smell was.'
But an evolutionary biologist would instead reason :
'Its because skunks would be easy victims for predators if they didnt defend themselves with bad smells. Natural selection made skunks evolve to secrete bad-smelling chemicals.'
The chemist has offered a proximate explanation, that is, the mechanism immediately responsible for the observation that was to be explained. The evolutionary biologist has instead offered am ultimate explanation - the function or chain of events that caused the mechanism to be present.
Similarly, studies of aging are pursued independently by two groups of scientists who scarcely communicate - one seeking a proximate explanation, the other an ultimate explanation. I shall argue that aging cannot be understood unless we seek both explanations simultaneously. I expect that the evolutionary (ultimate) explanation will help us find the physiological explanation of aging that has so far eluded scientists.


The mystery of human language origins is the most crucial in understanding how we became uniquely human. After all, it is language that allows us to communiate with each other far more precisely than any animal can. Language enables us to formulate joint plans, to teach one another, and to learn from what others have experienced elsewhere or in the past. Without language we could never have conceived and built Chartres Chapel - or V2 rockets. For these reasons, I speculate that the Great Leap Forward (the stage in human history when innovation and art at last emerged) was made possible by the emergence of spoken language as we know it.

Pidgin languages arise as a second language for colonists and workers who speak different first languages and need to communicate with others. Compared to normal languages, pidgins are greatly impoverished in the sounds, vocabulary and syntax. However, pidgins evolve rapidly into creoles when a generation of one of the groups contributing to a pidgin begins to adopt the pidgin itself as its native language. Creoles can express virtually any thought expressible in a normal language.
The process of creolization is a natural experiment in language evolution that has unfolded independently dozens of times in the modern world - from South America and the Pacific, to Africa, China and New Guinea, from at least the 17th to 20th centuries. What is striking is that the linguistic outcomes of all these independent natural experiments share so many similarities, both in what they lack and possess. Most creoles agree in placing a sentence's subject, verb and object in that particular order.
Creolization is accomplished by children in the process of acquiring the ability to speak, hearing the pidgin language as the dominant one. Presented with an inconsistent and impoverished model of human language in the form of pidgin, children spontaneously expand pidgin into a consistent and complex creole within a generation. They create their own language, for creoles possess grammatical features absent from the parent languages.

These similarities among croles seem likely to stem from a genetic blueprint that the human brain possesses for learning language during childhood. Such a blueprint has been widely assumed ever since the linguist Noam Chomsky argued that the structure of human language is far too complex for a child to learn within just a few years, in the absence of any hard-wored instructions. Such difficulties convinced Chomsky that children learning their first language would face an impossible task unless much of language's structure were already pre-programmed into them - he reasoned that we are born with a universal grammar. This pre-wired universal grammar would be like a set of switches, each with various alternative positions, which become fixed to match the grammar of the local language.
Derek Bickerton goes further than Chomsky and concludes that we are pre-programmed with a universal grammar with a particular set of switch settings - the settings that surface again and again in creole grammars. The pre-programmed settings can be overridden if they turn out to conflict with what a child hears in the local language around it. If Bickerton is correct one would expect children to learn creole-like features of their local language earlier and more easily than features conflicting with creole grammar. This reasoning might explain the notorious difficulty of English-speaking children in learning how to express negatives, or with word order in questions.


Modern studies of animal beahviour have been shrinking the list of features once considered uniquely human, so much so that most differences between us and so-called animals now appear to be only matters of degree. Vervet monkeys have a rudimentary language. You may not have considered vampire bats allied with us in nobility, but they prove to practise reciprocal altruism regularly (towards other vampire bats, of course). Among our darker qualities, murder has now been documented in innumerable animal species, genocide in wolves and chimps, rape in ducks and orangutans, and organized warfare and slave raids in ants.

Not until the Cro-Magnons, beginning around 40,000 years ago, do we have unequivocal evidence for art surviving in the form of the famous cave-paintings, statues, necklaces, and musical instruments. If we are going to claim that true art is unique to humans, then in what ways do we claim that ir differs from superificially similar productions of animals, like bird-songs, or elaborate bowers (nests)? Supposed distinctions are often put forward : that human art is non-utilitarian, that it is only for aesthetic pleasure. Lets scrutinize these claims more closely :

Bower-building provides a comprehensive test of male genes. It is as if the women put each of their suitors in sequence through a weight-lifting contest, sewing contest, chess tournament, eye test, and boxing tournament, and finally went to bed with the winner. Think of all the human suffering caused by the sad truth that beautiful sexy women or handsome Porsche-owning men often prove to have miserable genes for other traits.

There are several ways in which art helps us to survive and to pass on our genes. Art often brings direct sexual benefits to its owner. It is not just a joke that men bent on seduction invite a woman to view their etchings. In real life, dance and music and poetry are common preludes to sex.
Art brings indirect benefits to its owners - it is a quick indicator of status, which - in human as in animal socities - is a key to acquiring food, land and sexual partners. New Guinea villagers today decorate their bodies with shell, fur, and bird-of-paradise plumes. We know that New Guinea art signal superiority and wealth, because birds of paradise are hard to hunt, beautiful statues take talent to make, and both are very expensive to buy.
Elsewhere, as well, art is often viewed as a signal of talent, money, or both. Where once we signalled our stauts with bird feathers on our bodies, we now do it with diamonds and a Picasso on our wall. Nowadays we read increasingly often of art sold at auction for tens of millions of dollars, and of art theft. In short, precisely because it serves as a signal of good genes and ample resources, art can often be cashed in for still more genes and resources.

Art helps define human groups. Human have always formed competing groups whose survival is essential if the individuals in that group are to pass on their genes. Human history largely consists of the details of groups killing, enslaving, or expelling other groups. The winner takes the loser's land, sometimes also the loser's women, and thus the loser's opportunity to pass on genes. Group cohesion depends on the group's distinctive culture - especially its language, religion, and art (including stories and dances), hence art is a significant force behind group survival. Even if you have better genes than most of your fellow tribesmen, it will do you no good should your whole tribe (including you) get annihilated by some other tribe.
By now, you're probably protesting that I have gone completely overboard in ascribing utility to art. Is private satisfaction not a (the?) main reason for our art? Of course. To maintain that art is useful is not to deny that art provides pleasure. Indeed, if we were not programmed to enjoy art, it could not serve most of its useful functions for us.


How many civilizations of intelligent beings like ourselves must be out there? There are two signs of intelligent beings elsewhere in the universe that might be detectable on earth - space probes and radio signals. We ourselves are already becoming effective at sending out both, so surely other other intelligent creatures have mastered the necessary skills. Where, then, are the expected flying saucers? Given the billions of stars, and given the abilities that we know did develop in our own species, we ought to be detecting flying saucers or at least radio signals.

Think again of those astronomers who beamed radio signals into space from Arecibo, describing Earth's location and its inhabitants. In its suicidal folly that act rivalled the folly of the last Inca emperor, Atahuallpa, who described to his gold-crazy Spanish captors the wealth of his capital and provided them with guides for the journey. If there really are any radio civilizations within listening distance of us, then for heaven's sake let's turn off our own transmitters and try to escape detection, or we are doomed. Any advanced extraterrestrials who discovered us would surely treat us in the same way we treat chimpanzees, or techincally less advanvced human cultures.
Fortunately for us, the silence from outer space is deafening. Yes, out there are billions of galaxies with billions of stars. Out there must be some transmitters as well, but not many, and they do not last long. Probably there are no others in our galaxy, and surely none within hundreds of light-years of us.
What woodpeckers (they are the only species on the planet to have developed means to dig holes in living trees to eat insects living under bark) teach us about flying saucers is that we are unlikely to ever see one. For practical purposes, we are unique and alone in a crowded universe. Thank God!


First contact patrols had a traumatic effect that is difficult for all of us living in the modern world to imagine. New Guinean highlanders 'discovered' in the 1930s, and interviewed fifty years later, still recalled perfectly where they were and what they were doing at that moment of first contact. Perhaps the closest parallel, to modern Americans and Europeans, is our recollections of one or two of the most important political events of our lives. Most Americans of my age recall that moment on 7 December 1941 when they heard of the Japanese attack on Pearl Harbor. We knew at once that our lives would be very different for years to come, as a result of that news. Yet even the impact of Pearl Harbor and the resulting war on American society was minor, compared to the impact of a first-contact patrol on New Guinea highlanders. On that day, their world changed forever.

New Guinea shows linguists what the world used to be like, with each tribe having its own language, until the rise of agriculture permitted a few groups to expand and spread their tongue over large areas. It was only about 6,000 years ago that the Indo-European expansion began, leading to the extermination of all prior western European languages except Basque. The Bantu expansion within the last few millennia similarly exterminated most other languages of tropical and sub-Saharan Africa, just as the Austronesian expansion did in Indonesia and the Phillipines. In the New World alone, hundreds of American Indian languages have become extinct in recent centuries.
The range of cultural practices in New Guinea also eclipses that within equivalent area elsewhere in the modern world, because isolated tribes were able to live out social experiments that others would find utterly unacceptable. Forms of self-mutilation and cannibalism varied from tribe to tribe. Styles of sculpture, music and dance varied greatly between villages.
Alternative models of human society are rapidly disappearing, and the time has passed when humans could try out new models in isolation. At some point within the last decade of the 20th Century, we can expect the last first contact, and the end of the last separate experiment at designing human society.
While the last first contact will not mean the end of human cultural diversity, much of which is proving capable of surviving television and travel, it will mean a drastic reduction. But when I try to think of reasons why nuclear weapons will not inexorably combine with our genocidal tendencies to break the records we have already set for genocide in the first half of the 20th century, our accelerating cultural homogenization is one of the chief grounds for hope that I can identify. Loss of cultural diversity may be the price that we have to pay for survival.

Tasmania is a mountainous island similar in area to Ireland and lying 200 miles off Australia's southeast coast. Whenn discovered by Europeans in 1642, it supported about 5,000 hunter-gatherers related to the Aborigines of the Australian mainland and with perhaps the simplest technology of any modern peoples. Tasmanians made only a few types of simple stone and wooden tools. Like the mainland Aborigines, they lacked metal tools, agriculture, livestock, pottery and bows and arrows. Unlike the mainlanders, they also lacked boomerangs, dogs, nets, knowledge of sewing, and ability to start a fire.
Since the Tasmanians' sole boats were rafts capable of only short journeys, they had no contact with any other humans since the rising sea level cut off Tasmania from Australia 10,000 years ago. Confined to their private universe for hundreds of generations, they had survived the longest isolation in modern human history - an isolation otherwise depicted only in science fiction. When the white colonists of Australia finally ended that isolation, no two peoples on Earth were less equipped to understand each other than were Tasmanians and whites.
The tragic collision of these two peoples led to conflict almost as soon as British sealers and settlers arrived around 1800. Whites kidnapped Tasmanian children as labourers, kidnapped women as consorts, mutilated or killed men, trespassed on hunting grounds, and tried to clear Tasmanians off their land. Thus, the conflict quickly focused on lebensraum, which throughout human history has been amond the commonest causes of genocide. The last Tasmanian, a woman named Truganini, died in 1876, in the resettlement camp on Flinders island.

Perhaps the commonest motive for genocide arises when a militarily stronger people attempt to occupy the land of a weaker people, who resist. Among the innumerable straightforward cases of this sort are not only the killing of Tasmanians and Australian Aborigines by white Australians, but also the killings of American Indians by white Americans, of Araucanian Indians by Argentineans, and of Bushmen and Hottentots by the Boer settlers of South Africa. Another common motive involves a lengthy power struggle within a pluralistic society [Rwanda/Burundi; ex-Yugoslavia; Zanzibar].
At the opposite extreme are scapegoat killings of a helpless minority blamed for frustrations of their killers. Jews were killed by fourteenth-century Christians as scapegoats for the bubonic plague, by early twentieth-century Russians as scapegoats for Russia's political problems, by Ukrainians after the First World War as scapegoats for the Bolshevist threat, any by the Nazis during the Second World War as scapegoats for Germany's defeat in the First World War. Racial and religious persecutions have served as the remaining class of motives.

Of particular in understanding our genocidal origins is the behaviour of two of our three closest relatives, gorillas, and common chimpanzees. Two decades ago any biologist would have assumed that our ability to wield tools and to lay concerted group plans made us far more murderous than apes - if indeed apes were murderous at all. Recent discoveries about apes suggest, however, that a gorilla or common chimp stands at least as good a chance of being murdered as the average human. Among gorillas, for instance, males fight each other for ownership of harems of females, and the victor may kill the loser's infants as well as the loser himself. Especially instructive, because it could be documented in detail was the extermination of one of the common chimp bands that Jane Goodall studied, carried out between 1974 and 1977 by another band.

In short, all of our human hallmarks - art, spoken language, drugs, and the others - the one that has been derived most straightforwardly from animal precursors is genocide. Chimpanzee behaviour suggests that a major reason ofor our human hallmark of group living was defence against other human groups, especially once we acquired weapons, and a large enough brain to plan ambushes. If this reasoning is correct, then anthropologists' traditional emphasis on 'man the hunter' as a driving force of human evolution might be valid after all - with the difference that we ourselves, not mammoths, were our own prey and the predator that forced us into group living.

When we consider early literate civilizations, written records testify to the frequency of genocide. The wars of the Greeks and the Trojans, or Rome and Carthage, and of the Asyrrians and Babylonians and Persians proceeded to a common end: the slaughter of the defeated irrespective of sex, or else the killing of the men and enslavement of the women. We all know the biblical account of how the walls of Jericho came tumbling down at the sound of Joshua's trumpets. Less often quoted is the sequel, Joshua obeyed the Lord's command to slaughter the inhabitants of Jerihco as well as Ai, Makkedeh, Libnah, Hebron, Debir and many other cities. This was considered so ordinary that the Book of Joshua devotes only a phrase to each slaughter, as if to say, of course he killed all the inhabitants, what else would you expect? The sole account requiring elaboration is of the slaughter of Jericho itself, where Joshua did something really unusual; he spared the lives of one family (because they had helped his messengers). We find similar episodes in accounts of the wars of the Crusaders, Pacific islanders, and many other groups.

That our urge to kill is restrained by our ethics almost all the time is obvious. The puzzle is : what unleashes it? Today, while we may divide the world's people into 'us' and 'them', we know that there are thousands of types of 'them', all differing from each other as well from us in language, appearance and habits. It is hard to transfer ourselves back into the frame of mind prevailing throughout much of human history. Like chimps, gorillas, and social carnivores, we lived in band territories. The known world was much smaller and simpler than it is today; there were only a few known types of 'them', one's immediate neighbours.
Humans, like hyena clans, practised a dual standard of behaviour, with strong inhibitions about killing one of 'us', but a green light to kill 'them' when it was safe to do so.
With time this ancient dichotomizing has become increasingly unacceptable as the basis for an ethical code. Instead, there has been some tendency towards paying at least lip-service to a universal code.
Despite this ethical conflict, numerous modern perpetrators of genocide have managed to take unabashed pride in their accomplishments. How do today';s practitioners of genocide wriggle out of the conflict between their actions and a universal code of ethics? They resort to one of three types of rationalizations, all of which are variations on a theme, 'Blame the victim'.
Firstly, most believers in a universal code still consider self-defence justified. This is a usefully elastic rationalization, because 'they' can invariably be provoked into some behaviour adequate to justify self-defence.
Possessing the 'right' religion or race or political belief, or claiming to represent progress or a higher level of civilization is a second traditional justification for inflicting anything, including genocide, on those possessing the wrong principle. There is an almost universal hierarchy of scorn, according to which literate peoples with advanced metallurgy (for instance, white colonialists in Africa) look down on herders (such as Tutsi, Hottentots), who look down on farmers (such as Hutu), who look down on nomads or hunter-gatherers (such as Pygmies,Bushmen).
Finally our ethical code rgards animals and humans differently. Hence modern perpetrators of genocide routinely compare their victims to animals in order to justify the killings.

What genocidal acts can we expect from Homo Sapiens in the future? A hopeful sign is that modern travel, television and photography enable us to see other people living 10,000 miles away as human, like us. Much as we damn 20th century technology, it is blurring the distinction between 'us' and 'them' that makes genocide possible. The modern spread of international culture and knowledge of distant peoples have been making it increasingly harder to justify.


Horses revolutionized warfare in a way that no other animal, not even elephants or camels, ever rivalled. Soon after their domestication, they may have enabled herdsmen speaking the first Indo-European languages to have begun the expansion that would eventually stamp their languages on much of the world. A few millenia later, hitched to battle chariots, horses became the unstoppable Sherman tanks of ancient war. After the invention of saddles and stirrups, they enabled Atilla the Hun to devastate the Roman Empire, Genghis Khan to conquer an empire from Russia to China, and military kingdoms to arise in West Africa. A few dozen horses helped Cortes and Pizarro, leading only a few hundred Spaniards each, to overthrow the two most populous and advanced New World states, the Aztec and Inca empires. With futile cavalry charges against Hitler's invading armies in September 1939, the military importance of this most universally prized of all domestic animals finally came to an end after 6,000 years.

Thanks to the global expansion of Europeans since 1492 - especially of people from England, Spain, Portugal, France and Russia - nearly half the world's present population of five billion now speaks an Indo-European language as its native tongue.
Given all the resemblances among Indo-European languages, how could the differences among them have arisen? A clue is that any language whose written documents span many centuries can be seen to change with time. For example, modern English-speakers find 18th century English quaint but completely understandable; we can read 16th century Shakespeare, though we need notes to explain many of his words; but Old English texts, such as the poen Beowulf (c.750 AD) are virtually a foreign language to us. English has changed over the last 1,000 years.
As speakers of different languages spread into different areas with limited contact, the independent change of words and pronunciations in each area inevitably lead to different dialects, such as those that have arisen in different parts of the US in the few centuries since permament English settlement began in 1607. With the passing of more centuries, dialects diverge to the point where their speakers can no longer understand each other and they now rank as distinct languages. One of the best documented examples of this process is the development of the Romance languages after the break-up of Latin around 500 AD. Surviving written texts from the 8th Century onwards show us how the languages of France, Italy, Spain, Portugal, and Romania graudually diverged from Latin - and from each other.
One can reconstruct a family tree of all the Indo-European language branches, based partly on ancient texts. Language evolution proceeds by descent and divergence, just as Darwin demonstrated for biological evolution. In their language as well as their skeletons, modern Englishmen and Australians, who began to diverge with the colonization of Australia in 1788, are much more similar to each other than either are to the Chinese, from whom they diverged tens of thousands of years ago.

Today we take plant diffusion so much for granted that we seldom stop to think where our foods originated. A typical American or European meal might consist of chicken (of Southeast Asian origin) with corn (from Mexico) or potatoes (from the southern Andes), seasoned with pepper (from India), accompanied by a piece of bread (from Near Eastern wheat) and butter (from Near Eastern cattle), and wshed down by a cup of coffee (from Ethiopia).


We cling to belief in a Rousseau-esque fantasy that the past was a Golden Age of environmentalism, when people lived in harmony with Nature. In reality, human societies, including those of stone-age farmers and possibly hunter-gatherers aswell, have been undermining their own subsistence by exterminating species and damaging environments for thousands of years. We differ from our supposedly conservationist forebears only in our greater numbers, more potent technology for inflicting damage, and access to written histories from which we refuse to learn.

To science, we owe dramatic changes in our smug self-image. Astronomy taught us that our earth is not the centre of the universe but merely one of nine planets circling one of a billion stars. From biology, we learned that humans were not specially created by God but evolved along with tens of millions of other species. Now, archeology is demolishing another sacred belief: that human history over the last million years has been a long tale of preogress.

Among our major cultural hallmarks, agriculture is especially recent, having begun to emerge only 10,000 years ago. None of our primate relatives practises anything remotely resembling agriculture. For the most similar animal precedents, we must turn to ants, which invented not only plant domestication but also animal domestication.

When the Maoris landed, they found an intact New Zealand biota of creatures so strange that we would dismiss them as science-fiction fantasies if we did not have their fossilized bones to convince us of their former existence. The scene was as close as we will ever get to what we might see if we could reach another fertile planet on which life had evolved. Within a short time, much of that community had collapsed in a biological holocaust, and some of the remaining community collapsed in a second holocaust following the arrival of Europeans. The end result is that New Zealand today has about half of the bird species that greeted the Maoris, and many of the survivors are either now at risk of extinction or else confined to islands with few introduced mammalian pests. A few centuries of hunting had sufficed to end millions of years of moa history.

Madagascar and Polynesia merely provide well-documented examples of the extinction waves that probably unfolded on all large oceanic islands colonized be people before the European expansion of the last 500 years. Like New Zealand and Madagascar, all such islands where life had evolved in the absence of human beings used to have unique species of big animals that modern zoologists never saw alive. Mediterranean islands like Crete and Cyprus had pygmy hippos and giant tortoises (just as did Madagascar), as well as dwarf elephants and dwarf deer. The West Indies lost monkeys, ground sloths, a bear-sized rodent, and owls of several sizes: normal, giant, collosal and titanic. It seems likely that these bigs birds, mammals and tortoises too somehow succumbed to the first Mediterranean peoples or American Indians to reach their islands.
In addition to these pre-industrial extermination waves on islands, other species may have fallen victim to extermination waves on continents, in the more distant past. About 11,000 years ago, around the probable time that the first ancestors of American Indians reached the New World, most large species of mammals became extinct throughout all of North and South America. The disappearances involved species as varied as lions, horses, giant armadillos, mammoths, and saber-toothed cats.


Jared Diamond has a way of making us see familiar things afresh by encouraging us to look at them sideways-on. On one occasion, after he'd won a literary prize, he commented that the austere award ceremony would be difficult to organise in societies of other animals because all the sexually mature males would be busy trying to copulate with the females. To win an award in those societies would, he said, be so much more enjoyable.


Much of 'Third Chimpanzee' is based on Professor Diamond's articles for Discover magazine. You can read them in full on the Discover website :

The Best Ways to Sell Sex : looking at how humans transmit signals of their sexual worth.
Sex and the Female Agenda : what concealed ovulation tells us.
Why Women Change : the female menopause.

A Question of Size : why are pygmies so small?
Building to Code : why do we have weak and breakable bones?

Humanity's Worst Mistake : switching to farming from hunting and gathering


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