Humanity is fissile: everywhere it goes, it forms clans, Yoruba and Yanomamo, Mods and Rockers; so powerful is the urge to diverge, even shared ethnicity is optional. No wonder humanity is so hard to define. Taxonomy, designed to resolve such issues, is helpless where it matters most. Every species of animal and plant is uniquely defined as such on the basis of an objective description of its form and habits. All, that is, except one, Homo sapiens. Our entry in the Systema Naturae, devised by Linnaeus, says (more or less) ‘reader, know thyself,’ thus admitting the impossibility of seeing ourselves as others see us.
Thanks to the discovery of fossils of extinct relatives of humanity, and the application of Darwinian evolution, the boundary between humanity and the animal world, once thought unbridgeable, has been all but erased. The Darwinian emphasis has become a weapon in physical anthropology against the Post-Modernist tendency that sees the scientific worldview as one myth among many. That this is nonsense is self-evident: when one set of fashionable posturings has given way to another, the fossils will still exist.
The story the fossils have to tell is that our ancestry split from that of other African apes around five million years ago. These early hominids, best thought of as bipedal chimps, evolved into a multiplicity of specialised forms. Which, if any, can be described as the first representative of Homo is debatable. The first that was recognisably human was Homo erectus. This species appeared around two million years ago in Africa, and was the first of its kind to spread beyond that continent into Eurasia. Local populations evolved to give a number of distinct regional forms. The European variant became Neanderthal Man. The earliest Neanderthal-like creatures appeared around 300,000 years ago, and the last died out sometime after 30,000 years ago, a few thousand years after modern humans appeared in Europe.
The migration of Homo erectus out of Africa is accompanied by a sharp divergence of scientific opinion about what happened next. Some believe that the racial diversity in modern human form can be traced back to the regional variants of Homo erectus, more than a million years ago. For example, modern Europeans evolved from Neanderthals; modern Chinese from Asiatic Homo erectus. This ‘multiregionalist’ school is challenged by the so-called ‘Noah’s Ark’ school, whose adherents contend that all modern humans descend from a small population of fully modern humans living in Africa around 200,000 years ago. These people spread throughout the world, reaching the Levant 90,000 years ago, Australia around 60,000 years ago, and Europe 40,000 years ago. Indigenous populations were quickly replaced, and contributed no genes to modern humanity. Neanderthal blood courses in no one’s veins.
At the moment, the evidence favours the ‘Noah’s Ark’ school. Genetics, as well as examination of the fossils, points to a recent common origin in Africa. Physical differences between races are superficial, and any human can, in principle, mate with any other to produce viable offspring. ‘Noah’s Ark’ accords with current thinking in zoology, that new species arise in small populations which then spread more widely, competing with similar forms and often replacing them.
The multiregionalist view supposes that several distinct lineages evolved in parallel for a long time. A small amount of exchange between neighbouring populations would keep the entire species inter-fertile. This, not the recent common ancestry, is why the Yoruba and Yanomamo are capable of intermarriage, despite hundreds of thousands of years of separate evolution. Although this may be possible in principle, it is unlikely in practice, because of the zoological observation that species with extensive ranges tend to fray at the edges. There are several examples of animals which belong to the same species, but to opposite ends of its range, proving incapable of interbreeding should they meet, and behaving as members of distinct species. That this is not the case among humans speaks against multiregionalism, but in favour of a recent common ancestry.
Chris Stringer of the National History Museum in London is the best-known exponent of the Noah’s Ark idea, which he argues for in African Exodus. The two competing views are thrown into sharp contrast by what happened in Europe, where modern humans replaced the indigenous Neanderthals. Stringer’s star rose dramatically when new dating techniques showed that caves on Mount Carmel in Israel were occupied by modern humans almost 100,000 years ago, before the Neanderthals. Indeed, Neanderthals and moderns seem to have occupied the same caves but at different times, as if they were two separate species, with no sign of intermingling, or of evolution between one form and the other.
Why it took another 50,000 years for modern humans to enter Europe is a puzzle. The solution may be connected with the appearance of modern human behaviour. Although the first modern humans looked just like ourselves, they behaved quite differently. Nothing distinguishes their tool-making ability from that of Neanderthals or Homo erectus. The appearance of Homo erectus coincided with that of the hand axe, the classic stone-age implement, whose precise function is unknown. For more than a million years, Homo erectus and its descendants knocked out hand axes of near-identical form all over the world. Discarded hand axes may litter entire landscapes: a flawed half-made implement was not bodged imaginatively into something else, it was discarded, and the craftsman would start again from the beginning, with a new piece of flint, as if the instructions for making a hand axe were hard-wired into the brain, and any deviation from them inconceivable.
This uniformity contrasts with the sudden appearance in Europe around 40,000 years ago (perhaps slightly earlier in Africa) of cultural phenomena which, unlike the hand axe, can be easily understood by people today – art, personal adornments and a wide variety of implements, associated with highly local and ephemeral cultural traditions and stimulated by long-range contacts between scattered populations. The monotony of the stone tools produced before the ‘cultural explosion’ suggests that the people who made them did not think of artefacts as ‘things’ in cultural terms, and rarely came into contact with people outside their own immediate clan. These tools were products of instinct, made in the same stereotyped way that birds make nests.
Nobody knows why the appearance of modern humans antedates modern human behaviour. Faint anticipations of this, in isolated communities, which came to nothing, suggest that long-range interchange was necessary to keep culture going. This kind of interaction, James Shreeve suggests in The Neanderthal Enigma, explains much of modern human behaviour, especially the tendency towards notions of tribal self-definition. Neanderthals did not range far from home, so never developed similar links with their own kind.
As Robert Foley shows in Humans before Humanity, Darwinian gradualism means that we crossed no particular cultural rubicon. Whatever it is that makes us human may depend on the complex interaction of all sorts of small changes in human reproductive and social behaviour. Foley exposes as facile those hypotheses that point to one particular characteristic – bipedalism, say, or a large brain – as the ‘key’ to humanity. Characteristics tend to reinforce or negate one another in complicated patterns of feedback, during the evolution of integrated organisms.
Darwin envisaged evolution as possible only over vast spans of time. But the passage of periods of time vastly greater than is conceivable in everyday terms, ‘deep time’ as it is now called, has a quality all its own. The difference between ‘three million years’ and ‘this time next week’ is more than simply arithmetical. Thomas Hardy’s use of ‘deep time’ in his novels has not been lost on scientists, and has been the subject of a recent reappraisal by the palaeontologist Kevin Padian. Hardy’s characters are often first seen as minuscule figures set against a vast backdrop of space and time. Colin Tudge follows this line in The Day before Yesterday, but his message, unlike Hardy’s, is that there is no destiny: humanity was not fated to happen as an inevitable link in the chain between apes and angels.
Evolution is often seen as progression – Stephen Jay Gould has assembled a collection of advertisements in which the advanced state of some product or other is compared with humanity’s relentless progression from the apes, by way of a number of missing links. That this image is ingrained is worrying, and stems from a widespread misreading of Darwin. Terms such as the ‘survival of the fittest’ and the ‘struggle for life’ give a picture of nature as a constant battleground, where species become better at fending off the competition. It is natural to think of the outcome in terms of linear progression.
Evolution on the scale of deep time doesn’t work like that. New species tend to emerge from small, peripheral populations, whose isolation from the mainstream depends on freak accidents rather than progressive evolution. These small populations evolve very quickly: the direction they take is governed more by chance than by natural selection. Natural selection is very good at the day-to-day genetic housekeeping that keeps species in tune with their environments, but it may be rather remote from the decisive steps in evolutionary change.
The products of evolution are less like a chain than an unkempt bush of lineages, most ending in extinction. That Homo sapiens is the only extant member of its family is unfortunate, for this reinforces the impression of progression, of one form of human giving way to the next. The truth is that, until recently, two or more types of human occupied the globe simultaneously – that we are sole residents today is highly unusual. This comes as a shock, because we are so used to thinking of humanity’s uniqueness, the natural outcome of a string of evolving ancestors, as preordained.
What would the world be like today, for example, had modern humans been unable to displace Neanderthals from Europe, and Homo erectus still clung on in remote parts of Borneo and New Guinea? Historical precedent suggests that the fate of Homo erectus would be rapid extinction at the hands of the moderns – in the last century, native Tasmanians were hunted to extinction as if they were wild animals. In the real world, moderns did displace Neanderthals from Europe, but this outcome was far from inevitable. The Neanderthals were as big and as clever as we are, despite their lack of long-range social organisation, and they held out for thousands of years before becoming extinct. Extinction is the only inevitability for any species. Given the prevailing view of humanity as something special, it’s as well to realise that our own species will become extinct in a few hundred thousand years’ time.
The misguided notion of progression also blinds us to the zoologically obvious – that species, even extinct ones, were complete in themselves. They were too busy surviving to have time to sit and wonder where evolution would take them. Homo erectus was a specialist predator, sharing a world with close relatives, the australopithecines, who were equally specialist vegetarians.
As Alan Walker shows in The Wisdom of Bones, to view Homo erectus as a kind of missing link would be a mistake. Walker’s is a case-history of a startling find, the nearly complete skeleton of an African adolescent male Homo erectus, who died near the shores of Lake Turkana in Kenya, 15,000 centuries ago. Walker tries to envisage what this boy might have been like in life. He was tall, strong, a tool-maker, social and a predator. But the body of a teenager contained the brain of an infant. His was a world without language. Not that these were handicaps: Homo erectus was the first of its kind to leave Africa, and did nicely for more than a million years. It was not a missing link between Them and Us, but a creature with its own agenda, a lion with the body of an ape. Were the Turkana boy to come alive, his inhumanity would be striking: ‘In his eyes was not the expectant reserve of a stranger but the deadly unknowing I have seen in a lion’s blank yellow eyes. He may have been our ancestor, but there was no human consciousness within that human body. He was not one of us.’
So much for Homo erectus. Whether we could have engaged Neanderthals on human terms is a much more difficult question. Their image in scholarship and literature has been influenced more by their closeness than their distance from us. The lesson of The Neanderthal Enigma is that every technological novelty dreamed up by modern humans tends to show the monotony of Neanderthal culture in an even poorer light. History is written by the winners, but in a poignant twist, Shreeve looks at humanity from the perspective of the vanishing Neanderthals.
In the sudden spasm 40,000 years ago, humanity (the winners) acquired all the external trappings we think of as defining our own tribe. The Neanderthals, in contrast, just pottered around, doing the same kind of timeless nothing-in-particular they’d done for 300,000 years, for all the world like an extended episode of Winnie-the-Pooh (only with real Heffa-lumps). Archaeology shows that wherever modern humans advanced, Neanderthals retreated. Where once they roamed freely, from central Asia to the Atlantic, by 30,000 years ago they had become confined to isolated, remote areas in France and Spain. That modern humans with their material culture arrived in Europe around 40,000 years ago looks too close for comfort. The usual story leads inescapably, and wrongly, to the conclusion that superior humans were better ‘adapted’ to survive than the clodhopping Neanderthals, who were slaughtered, bred out of existence, or driven into marginal areas. There is no evidence for any alternative but the last.
Ice-Age Europe was not a single gladiatorial arena in which species fought for supremacy, but a subtle and complicated ecological patch-work, in which each species did its own thing, oblivious to the rest. All it would have taken for humans to have swept the board would have been a small increase in child survival relative to that of Neanderthals. In terms of individuals, the difference would hardly have been noticeable. But after 10,000 years, the larger numbers and densities of modern human populations would have deprived the Neanderthals of resources – the two species needn’t even have come into contact. There is no compelling evidence that modern humans have Neanderthal genes, and the impedimenta of human warfare are absent. Nobody has unearthed a Palaeolithic version of the killing fields.
This model may seem strange to anthropologists weaned on historical accounts of human conflict, written against purely historical spans of time. But if the moderns bested the Neanderthals in combat, enslaving Neanderthal females in the traditional modern human manner, it was a war that lasted twice as long as recorded human history, and modern Europeans should carry Neanderthal genes. People seem unable to grasp the immensity of the time-scale involved, and treat the demise of the Neanderthals as a single event. What is needed is the longer and less emotive perspective of zoology, where precedents exist for this kind of species replacement. For example, the decline of the native British red squirrel, now very rare, and the rise of the almost ubiquitous grey variety – an American import – can be ascribed to a slight increase in the latter’s breeding success. The countryside is not littered with the bony results of intersciurine strife, nor are there grey squirrels with traces of bastard redness.
There is evidence that the last Neanderthals ‘borrowed’ some aspects of modern stone-tool technology, but none to suggest they cowered wretchedly to the last in dismal caves, expiring from remorse and envy. The truth is, Shreeve says, the Neanderthals had no overriding need for modern innovations. Their comfortable, unspectacular world was such that they identified directly with the things within it. Symbolic representation was superfluous. Indeed, symbolism, a symptom of the dissonant sectarianism of modern humanity, was a makeshift of our ancestors who, having become divorced from nature in the ‘cultural explosion’, tried hard to find some path back to it. Shreeve reminds us of the famous thought experiment in which a Neanderthal is washed, shaved, dressed in coat and hat, and let loose on an underground train.
The original purpose of this thought experiment was to imagine what the other commuters would think of him. Would he go unnoticed, or stand out as grotesque? It is still an interesting question. But there is a much more intriguing one left unasked. I see the Neanderthal clutching on to a pole in that shaking metal cage, staring at the commotion of diverse and unfamiliar faces which do not look back, amazed by the unholy smells and sounds that everyone else is so strangely ignoring, and I wonder.
What would he think of us?