Out of Eden: The Peopling of the World (18 page)

He then draws attention to the mainly Middle Palaeolithic tools of earlier modern humans, concluding:

In sum, anatomical and behavioral modernity may have appeared simultaneously in Europe, but in both the Near East and Africa, anatomical modernity antedates behavioral modernity, at least as it is detectable in the archeological record. This observation is difficult to explain. Perhaps . . . the earliest anatomically modern humans of Africa and the Near East were not as modern as their skeletons suggest. Neurologically, they may have lacked the fully modern capacity for culture. This may have appeared only as recently as 40,000 to 50,000 years ago when it allowed [what were by] then fully modern humans to spread rapidly throughout the world.
¹⁵

In these explicit biological statements we have one dominant conventional out-of-Africa model that places the chronological and genetic threshold to our modernity (behavioural and neurological) at no more than 50,000 years ago, in West Eurasia and after the out-of-Africa dispersal. This model was conceived before 1989, at a time when it was believed that Australia was colonized only 40,000 years ago. In other words, Klein could interpret the evidence to allow for Australia – and hence also Asia – to have been colonized by Anatomically Modern Humans only after the start of the European Upper Palaeolithic. This made it possible for him to argue that these new ‘neurally enhanced’ moderns in Europe could have then moved on to colonize the rest of the non-African world. Klein published a second edition of his book in 1999, by which time he acknowledged, on the last couple of pages, the problem of possible earlier Australian (and Asian) colonization by 60,000 years ago, and the possibility of harpoon fishing in Africa between 90,000 and 155,000 years ago. In his conclusions he still, however, returns to the argument of a neurological evolutionary (i.e. genetically driven) revolution in Europe 40,000–60,000 years ago: ‘to me it suggests that the
fully modern capacity for culture may have appeared only about this time [50,000 years ago]’.
¹⁶

Even before we consider the evidence, we can see that this argument implies a biologically deterministic approach to cultural evolution. It assumes that each cultural advance is determined or ‘allowed’ by a genetic change. As I mentioned in the Prologue, human (or other primate) culture is first invented, then learnt and added to from generation to generation. Each advance or skill does not come out of a new gene. Rather, new behaviours come first and the genetic modifications that best exploit those new behaviours come afterwards. In other words, the change of culture precedes the change of body – not the other way round. Furthermore, there are predictable geographical differences of culture. If a particular invention in one region led to other local inventions, the accelerated pace of innovation would give that region a head start. So regional differences in the rate of cultural progression should be expected, even within one human species.

Did a European wisdom gene spread to everyone else?

There are several inescapable logical assumptions in Klein’s argument that fully ‘neurally modern’ humans appeared only after 40,000–50,000 years ago. First there is the explicit implication that early African moderns were biologically less than modern – in other words, they did not have the neurological capacity to develop modern behaviours. This strange conclusion would inevitably apply to those moderns left in Africa, and also to the first moderns migrating into Asia and on to Australia, since it is now generally accepted that these colonizations took place quite some time before 50,000 years ago (the earliest possible time for which the Upper Palaeolithic can be identified in the Eastern Mediterranean). What do these hypothetical conclusions mean? They would mean first that the direct ancestors of today’s Africans living between 50,000 and 130,000 years ago were biologically incapable of developing or using Upper
Palaeolithic behaviour and technology. They would not be able to paint, carve, trade, organize, and so forth. Many say that they could not speak – or, if they could, that their speech was ‘primitive’. With such disadvantages, presumably they could not, given the opportunity, drive cars or fly planes; compose and play soul, spirituals, reggae, classical music, and jazz; or become doctors, financiers, and geneticists. The mitochondrial DNA and Y-chromosome trees imply that today’s Africans are descended mainly from lines present before 50,000 years ago and not from lines outside Africa. So, why can today’s African descendants do all these things their ancestors were supposedly genetically incapable of?

There is a further logical problem. If Europeans were the first biologically modern humans and were isolated comparative latecomers, what about the rest of the world? How did they catch up? All living modern humans are fully ‘Anatomically Modern’, and we can trace back our genetic trail to a small ancestral group that started branching in Africa around 190,000 years ago. At no point after that did the total modern population number less than a thousand,
¹⁷
so we have to imagine that one group inevitably led, by expansion and branching, to many groups.

The first nucleus of moderns thus expanded, split, and spread early, some branches never to meet again until recent times. This effect of ‘no-return’ separation was never so final as when the one and only successful out-of-Africa group crossed the Red Sea and headed for India and Australia. If, as many evolutionists believe, there was some late genetic change in Europe that made us behaviourally modern as opposed to behaviourally ‘archaic’, this mutation (or mutations) must have occurred at a particular time in individual Europeans after 45,000 years ago – and, obviously, outside Africa.

A new mutation would have been passed on to all descendant populations that received the mutated gene, but would not have been shared by ‘cousins’ and their descendants. The only exception
to this would be if the mutated gene was subsequently shared as a result of cross-marriage. The chance of such cross-marriage would diminish sharply as groups separated and spread around the world. So if there really was, say, a ‘painting mutation’ or a ‘speech mutation’, only those descended from the individual who developed that mutation should inherit the skill. So, if the ‘behaviourally fully modern’ cluster of mutations initially evolved locally in Europeans 40,000–50,000 years ago, then the rest of the colonized world – the Asians, Africans, and Australians – would not be able to paint, carve, speak, make blades, or place a bet on a horse. Nor would their modern descendants. This is clearly absurd, for they can do all those things.

By this argument, the only way that the original modern colonies of Asians, Africans, and Australians could come up to speed with a European Upper Palaeolithic culture that resulted from a genetic mutation would be if they received infusions of all those new ‘culture genes’. The only biological way of infusing genes, or gene flow, is by migration and intermarriage. But it would not be enough just to have a few foreign cousins. To change all the descendants’ capabilities, the old hypothetical ‘cultural genes’ would have to be completely replaced by the ‘new’. Curiously, this massive gene flow is just the same argument that the discredited multiregionalists use to explain how modern human populations evolved separately in different parts of the world from local
Homo erectus
variants, yet ended up looking more like one another than the local
erectus
types. The main problem with the gene-flow levelling theory is that the geography of the mtDNA and Y-chromosome trees shows no evidence of such large-scale inter-regional mixing

Let’s take a cultural example. For Australians to have been producing rock art 32,000 years ago (which, apparently, they did), at the same time as it first appeared in Europe, would have required an instantaneous and massive gene flow round the globe from Europe to biologically ‘enable’ them to get to that level. It is a ludicrous
idea, which can easily be tested. We can see from the genetic record that although modern Australians share with Europeans the two out-of-Africa M and N ancestors from over 80,000 years ago, they preserve their own M and N types. There is no evidence that they are descended from Europeans. Nor was there any significant gene flow from Europe to Australia during the rest of the Palaeolithic.
¹⁸

Lack of genetic mixing after out-of-Africa is the general rule

The genetic evidence from the male-line and female-line markers, the Y chromosome and mtDNA, in fact shows the opposite of massive gene flow. One of the most important messages of the Y-chromosome and mtDNA stories is that, after the initial modern human dispersals out of Africa, each Old World and Antipodean region became settled, and little if any further inter-regional gene flow happened until the build-up to the last great glaciation 20,000 years ago. Both genetic marker systems show clear regional and intercontinental divisions.

Cultural diffusion (a sort of seepage or spread of culture not requiring much people movement) during the Palaeolithic is a more likely method of long-distance cultural transmission and one which does not necessarily require gene flow. However, could it really have been possible for 32,000-year-old Australian rock art to be derived from that of Europe at the same time? The culture would have to have been passed halfway around the world in an impossibly short space of time.

The simplest answer, which does away with this paradox and similar ones, is that the African ancestors of all non-Africans came out of Africa painting, talking, singing, and dancing – and fully modern! There is thus much biological as well as logical evidence
against
a genetic evolutionary event leading on to fully modern humans 40,000 years ago in the Levant, Europe, or anywhere else outside Africa. This leads us on to examine the direct archaeological
evidence and anthropological arguments for the simpler model, namely that the first Anatomically Modern Africans were already fully modern in their intellectual potential.

The cultural evidence

Two well-known teams of anthropologist and archaeologist have recently examined the tools, technology, and lifestyle of our ancestors to measure their potential. Their approaches and discussion frameworks were very different but to my reading, their conclusions were broadly the same. While looking at their work we need continually to put archaeological evidence of variations in technology between different groups back into the perspective of Yali’s question. Conventional writing and reading were invented over 4,000 years ago in the West, but no one argues for a writing gene; the same goes for the dramatic developments of the past century – radio, television, computers, computer language, spacecraft, and so on. In other words, we cannot use the sophistication of any particular recent human technical invention as a biological milestone. Also, much evidence of technical and symbolic culture, such as wood-carving and art painted on wood, is perishable, so there may be less evidence of earlier manifestations in a wood-using culture.

This means that, without adequate context, we cannot assume that evidence of technical innovations points to a biological evolution. From our knowledge of how cultural innovations have spread during our own, recorded, history, we would expect a generally slow cultural improvement to be punctuated by apparent local revolutions, which would then diffuse farther afield and eventually result in an overall acceleration. What is perhaps most important when examining the origins of the Upper Palaeolithic revolution is to look for the geographical location of the immediate precursor culture: North Africa, or South Asia?

Using stone trails to follow people round the world

We should of course start with that most abundant and durable record: stone tools. The Cambridge team of Robert Foley, anthropologist, and Marta Lahr, palaeontologist, have carried out an in-depth review of stone and bone evidence from around the world to see if one really can fit stone technology types to different human species, ancient and modern. Their main conclusion was that the worldwide spread of modern humans is most comprehensively defined by the dated appearance of so-called Mode 3 technology (
Figures 2.1
and
2.3
) – a technical threshold that was passed by our ancestors
Homo helmei
in Africa around 300,000 years ago. Originally defined as the use of a specially prepared stone core from which flake tools could be struck off, Mode 3 is really the Middle Palaeolithic under another name. Another way of looking at Mode 3 is not just as a change in knapping technique, but more in terms of the advance from large, heavy hand-axes to smaller stone tools, including sharp flakes, that could be hafted.
¹⁹
Mode 3 thus coincides with the earliest appearance of the large-brained
Homo helmei
, who in Foley and Lahr’s view were the common ancestor for both ourselves and Neanderthals. Mode 3 became the main technology used by all members of this latest human family – including moderns – until after 50,000 years ago. The use of prepared cores to generate flakes was conceptually the most complex development, and occurred in the Lower Palaeolithic. If these people were smart enough to make prepared cores, they were probably smart enough to make blades.

Blade production from prepared prismatic cores is the second hallmark technique. However, it is much less useful as a marker of the spread of modern humans, being a late and local event in Europe and around the Mediterranean (and later still in Africa and Asia, though not in Australia). And it is perhaps not reliable as a specific marker for fully modern humans outside Africa, because there is evidence for blade production by others, including contemporary non-moderns (such as the Chatelperronian industries, mentioned in note 11) and earlier modern Africans (such as in Howieson’s Poort, South Africa, 60,000–90,000 years ago), in what are otherwise Middle Stone Age settings. As a final twist, these short-term African appearances of ‘smart’ blades were later replaced again by typical Mode 3 industries. Some archaeologists speculate that blades were invented several times before the Upper Palaeolithic and then forgotten.
²⁰
Perhaps the two main practical advances of the Upper Palaeolithic were in blade use: diversity of tools and economy of raw material.