Lone Survivors (35 page)

What is puzzling here is that there are actually very few human burials known from the Middle Stone Age of Africa, and the best early examples come from the Middle Paleolithic of Israel about 100,000 years ago. In contrast, there are many late Neanderthal interments in western Eurasia, but we don't pick up the practice again in modern humans until about 40,000 years ago in North Africa, the Middle East, and then Europe. It's certainly possible that early moderns engaged in other methods of disposal than burial, just as people do today—in the open, on platforms, up in trees, or on ceremonial fires. This seems to be the case for some of the first moderns in Europe, too—the Aurignacians—whose bodily traces are mainly in the form of isolated and sometimes pierced human teeth rather than burials, suggesting that they preferred to carry traces of their enemies or their ancestors with them, rather than burying them.

Symbolism seems, then, to have been part of our African heritage, even if its recognition in the archaeological record is not a simple business. And what about language, which is assumed to have developed alongside symbolism? There are many different theories about the origin of human language, as we discussed in chapter 5, and it has been a source of great controversy since the time of Darwin—indeed, the venerable Linguistic Society of Paris amended its constitution to ban any discussion of the origins of language in 1866! We know that human infants have a powerful built-in capacity to acquire and then use language, and they will readily learn whatever language, or even languages, they are exposed to. As Darwin recognized during his travels, there is no relation between types of societies and the complexity of their language. For example, linguists consider that English is one of the easier languages for a nonnative to learn compared with a host of other languages ranging from Hopi, Circassian (North Caucasus), and Kivunjo (Tanzania) to Arabic. Darwin favored an origin of human language through imitation and recognized parallels between human speech and birdsong. Various hypotheses have been proposed for the first stages of such imitation, whether of animal sounds, of natural sounds like wind or thunder, or of spontaneous exclamations such as pain or surprise, which gradually took on new meanings. A distinct set of hypotheses proposes that language arose through specific social needs, whether to avoid dangers, to facilitate cooperative hunting, or, as Leslie Aiello and Robin Dunbar proposed, to take over the social function of grooming as group sizes increased in early humans. And we saw that there are also models that postulate a much more sudden and serendipitous origin of complex language through genetic changes that fortuitously enhanced the relevant brain pathways.

From my perspective, I think that simple languages must already have existed in early human species, given the complexity of behavior that is apparent at sites like Boxgrove and Schöningen in Europe and Kapthurin in Kenya, and so Neanderthals would have inherited and built on the language or languages acquired from their ancestors. But in my view it was only with the growing complexity of early modern societies in Africa that sophisticated languages of the kind we speak today would have developed, through the need to communicate increasingly intricate and subtle messages. And by using the word
need
here I am not implying, of course, that the need created the desired result; what happened was that useful variations in human behavior and communication would have been enhanced through selection, and this could have included humanly driven cultural or sexual selection, favoring the best communicators. Our languages are not just for the here and now, as earlier ones probably were, since through them we can talk about the past and future, about abstract concepts and feelings and relationships, and about the virtual worlds that we can create in our minds. We humans are collectors and curators par excellence, storing and employing a rich vocabulary to name and describe the worlds we inhabit, both physical and virtual.

Finally, in this discussion of language, as we saw with the workings of our brains, the power of thinking itself would have been enhanced by an increasing richness of expression. So if complex language originated in Africa, could it have had one single origin—a protolanguage from which all tongues today have evolved? This idea of monogenesis, and with it the theoretical possibility that we can work backward from present-day languages to reconstruct at least something of the prototype, is certainly appealing to me. Several linguists have produced vocabularies of some of the hypothesized first words, and even something of the way in which they might have been used, but this is a highly controversial area, and one where glottogonists (
glottogony
comes from the Greek for “language origin”) disagree strongly. For the moment, this is not an area in which we can draw firm conclusions, but the psychologist Quentin Atkinson has analyzed the number of phonemes (sound components) used in languages around the world and concluded that the global pattern closely mirrors that found in genes. Africa has the largest number and diversity of phonemes, and that number decreases as we move away from Africa. As Atkinson maintains, that would be consistent with an African origin for the languages of today, too.

In terms of innovation, we saw in chapter 1 that the apparently sudden florescence of the rich Upper Paleolithic societies of Europe seduced many in the last century to consider that this period marked the real arrival of fully modern humans, even if areas like the Middle East or Africa had been rehearsal grounds for the revolution that was to be finally expressed in the caves of France. But as we also saw, this Eurocentric viewpoint that the Cro-Magnons were the first “modern” people has been largely abandoned, although that is not to deny that something special did happen in the Upper Paleolithic of Europe. If Africa was actually at the forefront of Paleolithic innovations more than 40,000 years ago, why was that? As the anthropologist Rob Foley pointed out, the sheer size of Africa (one could easily fit China, India, and Europe into its surface area) and its position straddling the tropics certainly gave it advantages over any other area inhabited by early humans. The rapidity and repetition of climatic oscillations outside of Africa probably continually disrupted long-term adaptations by human populations in those regions.

Thus Neanderthals in Europe and the descendants of
Homo erectus
in northern China were constantly faced with sudden range contractions and the extinction of large parts of their populations every time temperatures sank rapidly, as they often did. And in the island regions of southeast Asia, where the descendants of
erectus
, and the Hobbit, and any similar relict populations lived, climate changes would have greatly disrupted connections between regions and populations, as sea levels rose and fell by one hundred meters or more. The local environments would also have been greatly affected by related changes in the monsoons and rainfall.

By comparison, in Africa, temperature and sea level changes were probably less damaging to its human inhabitants, and while there would certainly have been major changes in precipitation and environments, as we will discuss shortly, the continent nevertheless probably always had more people surviving there than any other region in ancient times. Given its larger human populations and its greater continuity of occupation, Africa probably always had more genetic and morphological variation than other parts of the inhabited world, giving greater opportunities for biological and behavioral innovations to both develop and be conserved. In this sense, it was perhaps more a matter of Africa being the place where early humans had the best chance of surviving, rather than being special in terms of a unique evolutionary pathway. This gives us an important clue to what eventually triggered our evolutionary success story.

As we saw in chapter 5, Africa shows the precocious appearance of features we associate with hunter-gatherers in recent times, such as planning ability, symbolic behavior, abstract thinking, marine exploitation, and enhanced innovations in technology. But, as we also saw, while such changes appear in some parts of Africa over 75,000 years ago, it is as though the candle glow of modernity was intermittent, repeatedly flickering on and off again. Most of the suite of modern features does not really take root strongly and consistently until much later, close to the time when humans began their final emergence from Africa about 55,000 years ago. Why was that? It is possible, of course, that the modern features were present in some African populations and not others, and as these groups moved around the landscape, their “modernity” seems to appear and disappear with their archaeological visibility. But I think another explanation is more likely, and this has to do with demography, the study of the size, structure, and distribution of populations through time and space, and the factors affecting population such as birth, death, and aging, migration patterns, and the environment. Valuable clues about the importance of demography can be found in the history of an island far away from Africa: Tasmania.

As sea levels have risen and fallen with the decline or growth of the Earth's ice caps, Tasmania has been intermittently joined to the mainland of Australia, and this was the case from about 43,000 to 14,000 years ago, allowing early Australians to reach there by about 40,000 years ago. Excavations in various caves show that the first Tasmanians adapted well to the cool, southerly conditions, with a variety of hunting and fishing weapons and tools and bone piercers that were probably used to manufacture the skin clothing and shelters that helped them survive the rigors of the last Ice Age. But from about 14,000 years ago, Tasmania was cast adrift from the mainland again by rising seas, and as the Earth warmed into the present interglacial, the landscape of the shrinking island changed to become more heavily forested. The original colonizers of Australia, including the ultimate ancestors of the Tasmanians, must certainly have made boats to reach the continent from southeast Asia, and those boats may have been made of bamboo. But if we asked some traditionally living aborigines in central Australia today to make us a seagoing boat (bamboo or otherwise), they would probably question our sanity, since this is no longer part of their lives and adaptations—in the absence of forests and large bodies of water. That situation seems to have applied in southern Australia and Tasmania when these regions separated at the end of the last Ice Age, meaning that their human populations lost contact with each other. While the mainland groups still had large areas of land with different environments available to them, as well as contact with each other, the Tasmanians now suffered from the previous loss of the knowledge needed to make seagoing craft. They were isolated on a shrinking island, with nowhere else to go, and this seems to have affected the pathways they then took.

Over the next 14,000 years, to judge from the archaeological record preserved in sites and the reports of the first Europeans to record their contact with aboriginal groups, the Tasmanians appear to have led an increasingly simplified life, forgoing apparently valuable skills and technologies, such as bone and hafted tools, nets and spears used to catch fish and small game, spear throwers and boomerangs, and anything but the simplest of skin clothing. Indeed, there were even reports that some groups had lost the ability to make fire at will, although this has been strongly disputed. Research suggests that these changes were the results of shrinking populations and loss of territories and resource bases, as well as the loss of contact with the mainland.

Anthropologists like Joe Henrich have argued that such changes interfered with the ability of populations to retain and pass on knowledge to each other and across the generations. For example, in a small population, an expedient short-term decision to, say, exploit seals on land for a few years rather than go fishing may have serious long-term effects if the knowledge needed to return to fishing had been compromised or even lost in the meantime. The resulting simplification of adaptations by the Tasmanians was the lowest-risk strategy to ensure survival in difficult times, but it was also accompanied by a loss of complex skills that would have been useful in the longer term. If there had been a subsequent return to glacial conditions and a lowering of sea level, conditions similar to those of the first Tasmanians could have been restored, but even then, unless they picked up lost skills from contact with the mainlanders, they would have needed to develop them from scratch, a process that could have taken many generations.

What happened in Tasmania may help to explain events in Africa more than 50,000 years earlier. As we saw, the evidence of modernity there is often disparate and discontinuous, like a flickering candle. What are we to make of archaeological sequences where typical Middle Stone Age assemblages are succeeded by apparently “advanced” Howiesons Poort artifacts, and then, in later deposits, typical Middle Stone Age material returns? Or what about the brief flowering of the Blombos people with their symbolic red ocher and variegated shell beads? We are perhaps misled by recent human history, where information storage in spoken, written, visual, or electronic form means that useful innovations are rarely lost, and the growth of “cultural” knowledge is incremental or even exponential. In the past, on the other hand, small populations would have been prone to population crashes or even extinction, or forced into relatively rapid movement or adaptation to survive, and this could have led to the regular loss of innovations that might have been useful in the longer term. Thus repeated “bottlenecking” did not just remove genes but also eradicated discoveries and inventions associated with the human populations concerned, and rapid environmental changes or population movements would have had the same effect. We can think, perhaps, of the people who crafted those beautiful wooden spears more than 300,000 years ago at Schöningen in Germany. Did that knowledge pass on continuously through to late Neanderthals over hundreds of millennia, or did a sudden temperature drop in northern Europe remove the spruce trees required to maintain that knowledge or even entirely wipe out those populations and their skills?