Lone Survivors (26 page)

Bowles posited the idea that if Paleolithic groups were relatively inbred and genetically distinct from each other, and warfare between groups was prevalent, then group selection through collaborative defense and attack could evolve and be maintained. Without warfare, a gene with a self-sacrificial cost of only 3 percent would disappear in a few millennia, but with warfare, Bowles's model showed that even levels of self-sacrifice of up to 13 percent could be sustained. He used archaeological data (although mainly post-Paleolithic) to argue that lethal warfare was indeed widespread in prehistory, and that altruistic group-beneficial behaviors that damaged the survival chances of individuals but improved the group's chances of winning a conflict could emerge and even thrive by group selection. Moreover, the model could work whether the behavior in question was genetically based or was a cultural trait such as a shared belief system. As mentioned above, Bowles's archaeological data do not come from the Paleolithic, but there is one observation that does resonate with his views: the French archaeologist Nicolas Teyssandier noted that the period of overlap of the last Neanderthals and first moderns in Europe was characterized by a profusion of different styles of stone points. This might reflect a sort of arms race to perfect the tips of spears, perhaps to hunt more efficiently, but equally this could suggest heightened intergroup conflict.

Social relations, cooperation and conflict, food acquisition, and changing age profiles could all have been important in shaping modern humanity, but one of the markers of
Homo sapiens
—language—was undoubtedly a key factor. For the primatologist Jane Goodall, the lack of sophisticated spoken language was what most differentiated the chimps she studied from us. Once humans possessed this faculty, “they could discuss events that had happened in the past and make complex contingency plans for both the near and the distant future … The interaction of mind with mind broadened ideas and sharpened concepts.” Despite the rich repertoire of communication in chimps, without a humanlike language “they are trapped within themselves.”

So how could such a critical thing as language evolve in humans, and was its evolution gradual or punctuational? Darwin certainly favored a gradual evolution, under the effects of both natural and sexual selection. He wrote in 1871:

With respect to the origin of articulate language … I cannot doubt that language owes its origin to the imitation and modification of various natural sounds, the voices of other animals, and man's own instinctive cries … may not some unusually wise ape-like animal have imitated the growl of a beast of prey, and thus told his fellow-monkeys the nature of the expected danger? This would have been a first step in the formation of a language.

As the voice was used more and more, the vocal organs would have been strengthened and perfected through the principle of the inherited effects of use; and this would have reacted on the power of speech. But the relation between the continued use of language and the development of the brain has no doubt been far more important. The mental powers in some early progenitor of man must have been more highly developed than in any existing ape, before even the most imperfect form of speech could have come into use, but we may confidently believe that the continued use and advancement of this power would have reacted on the mind itself, by enabling and encouraging it to carry on long trains of thought. A complex train of thought can no more be carried on without the aid of words, whether spoken or silent, than a long calculation without the use of figures or algebra.

In contrast to Darwin's gradualist evolutionary views, the linguist Noam Chomsky has long argued that modern human language did not evolve through Darwinian selection; in a sense, for him, it is an all-or-nothing faculty, emanating from a specific language domain in the brain that may have appeared through a fortuitous genetic mutation. He believes that all human languages, however different they may sound at first, are structured around a universal grammar that is already present in the brain of infants and which they use intuitively to interpret and then re-create the patterns of speech presented to them by the group into which they are born. The evolutionary psychologist Steven Pinker has shared some of Chomsky's views, in particular that there is a specific hard-wired domain for language capabilities in the brain. In his opinion, this domain generates
mentalese
(a term created by the cognitive scientist Jerry Fodor), an underlying and innate mental code out of which all human languages can be forged. However, Pinker parted from Chomsky in arguing that gradual genetically based change (comparable to that which eventually led to complex eyes) could have evolved the human “language organ” and its language-generating systems, in a series of evolutionary steps, with selection (either natural or sexual/cultural) favoring increased richness of expression.

Earlier I discussed the view of the archaeologist Richard Klein that there was a punctuational origin for modern human behavior in Africa about 50,000 years ago, and, to an extent, his views can be compared with Chomsky's. Klein critically assessed the evidence for “modern” behavior prior to 50,000 years and found it unconvincing. In his view it is only after that date that a consistent pattern of finds demonstrates the presence of things like increasing diversity and specialization in tools, undoubted art, symbolism, and ritual, expansion into more challenging environments, diversification of food resources, and relatively high population densities. As a trigger, he suggests there may have been “a fortuitous mutation that promoted the fully modern brain … the postulated genetic change at 50 ka fostered the uniquely modern ability to adapt to a wide range of natural and social circumstances with little or no physiological change.” He further speculates that this brain rewiring may have rapidly facilitated the full language capabilities of
Homo sapiens
, which up to then had been little different from those of earlier humans, and, as he recognizes, this is something that is very difficult to demonstrate from the fossil and archaeological record. Although I disagree with Klein about a unique “switch” that turned on modern human behavior, I agree with his views on the critical importance of language to our species.

However, there could have been premodern languages in earlier humans and in the Neanderthals. Robin Dunbar and the anthropologist Leslie Aiello argued that human language perhaps first developed through “gossip,” as a supplement to (and eventually a replacement for) social grooming. The activity of fur grooming is performed on a one-to-one basis by many primates to help maintain their relationships and social cohesion. Dunbar and Aiello speculated that without the benefit of language, the burgeoning size of
Homo erectus
groups would have required individuals to expend up to half their time on individual social grooming, leaving little time for other vital activities. But by allowing groups of early humans to chatter to each other, a primitive language could have facilitated social intimacy and cohesion, freeing up time otherwise spent in grooming.

In contrast, the psychologist Michael Corballis returned to Darwin's views on the importance of gestures as precursors of language, arguing that the brain areas that are important for language production in humans are actually concerned with manual actions in other primates. Similarly, the psychologist Michael Tomasello sees language as having evolved as a practical social tool for communication regarding requests, information, and cooperation. In his view, speech is the ultimate, and perhaps ultimately evolved, component of what we call human language, but it could have been preceded by gestures, just as it often is in human babies. Indeed, there is considerable evidence that we do communicate with each other—sometimes unconsciously—through our body language and posture, still an important vestige of our prelinguistic primate heritage. Other researchers have argued for a link between brain coding for toolmaking and for language, since both are sequential processes involving intention and finely controlled muscle actions; thus children learn to manipulate and assemble words as they are also manipulating and assembling objects. And it is certainly possible that parts of the brain that were already there and fulfilling different functions were co-opted to cope with the growing demands generated by language for storage, processing, and muscle control.

From my perspective, modern human language probably evolved out of growing social complexity over the last 250,000 years to bolster mind reading and communication, and I agree with the archaeologist Steven Mithen that by enhancing cognitive fluidity, language took modern humans into new and shared worlds that were unknown to our ancestors. The Neanderthals must have been highly knowledgeable about the world in which they lived, too (for example, about the materials from which they made tools and the animals they hunted). But in my view their domain was largely of the here and now, and they did not regularly inhabit the virtual worlds of the past, the future, and the spirits. After our evolutionary separation about 400,000 years ago, we and the Neanderthals traveled down parallel paths of developing social complexity and, with it, developing language complexity. For whatever reasons, we traveled farther, and the Neanderthals came to the end of their long road about 30,000 years ago.

Attempts have been made by scientists like Philip Lieberman and Jeff Laitman to reconstruct the speech capabilities of Neanderthals and other early hominins, based on the shape of the base of their skulls and the position of critical anatomical landmarks. In their view, modern humans possess a uniquely shaped tongue, throat, and vocal tract, facilitating the range and complexities of sounds required for fully human speech. Darwinian selection must have operated on variations in skull form, leading to its restructuring, and the modification of the throat from its previous dominant functions of breathing and swallowing toward the complexities of modern human speech capabilities, as long as the newly acquired vocal skills conferred advantage. The price we paid for this reshaping of priorities in the throat is a greatly increased risk of choking on our food compared with chimps and early hominins. In the case of the Neanderthals, their vocal tracts and capabilities were apparently closer to those of a two-year-old child than a modern adult; however, there is no doubt that if the Neanderthal brain was coding for complex language, even that kind of vocal tract would have done the job, albeit with a more restricted repertoire of sounds.

Returning to the checklist of modern human attributes that I discussed in the previous chapter, in my view modern humans had developed most of them by 60,000 years ago, even if they were not always present as a package all of the time from the evidence we have found so far: that is, complex tools, the styles of which may change rapidly through time and space; long-distance transport of valued materials such as stone, shells, beads, amber; evidence for ceremonies or rituals from art, structures, or complex treatment of the dead (the latter inferred from the Skhul and Qafzeh symbolic burials). But for some of the attributes, the evidence so far is either equivocal or only partly there, including formal artifacts shaped from bone, ivory, antler, shell, and similar materials; greater complexity of food gathering and processing procedures, such as the use of nets, traps, fishing gear, and complex cooking; art, including abstract and figurative symbols; and structures such as tents or huts for living or working that are organized for different activities such as toolmaking, food preparation, and sleeping and for hearths. Regarding higher population densities approaching those of modern hunter-gatherers, I will discuss this aspect later, in chapter 7, from the perspective of genetic data. And regarding increased cultural “buffering” to adapt to more extreme environments such as deserts or cold steppes, it may be that this aspect evolved more gradually as modern humans grew in numbers and dispersed to the ends of the Earth.

In chapter 4 I discussed how fossil foot bones from Europe and China showed that early moderns in both regions had seemingly discovered the benefits of footwear, and patterns of objects, such as sewn beads, pins, and toggles, in Cro-Magnon burials imply the existence of fitted clothing, as does the presence of eyed bone needles. Clothing would have been of great value to humans in colder climates, and although direct evidence for it has perished, it seems likely that the Neanderthals had the skin-working technology required to make at least basic clothes to keep the cold and wet off their bodies.

Replica of a mammoth carved from reindeer antler, from the Montastruc rock shelter, France. The original formed part of a spear thrower (atlatl) and is about 14,000 years old.

Many modern peoples in tropical and subtropical regions often wear little or no clothing, beyond what may be required for reasons of modesty or tradition, and humans do have the ability to adapt physically to colder climates. When Darwin and the
Beagle
visited the bitterly cold regions of Tierra de Fuego at the subpolar tip of South America, he was astonished to see that the native peoples wore little or no clothing and slept naked in the open. Native Australians also have physical adaptations that help them sleep at night in the outback, but interestingly Europeans seem physiologically poorly adapted to the cold—something they do not seem to have acquired from the Neanderthals, despite the likelihood of interbreeding. However, cold conditions were also present in Africa, in the highlands and in cloudless areas at night, and basic clothing and warm bedding would have been advantageous at times.