Lone Survivors

by Chris Stringer

  The following year, about fifteen meters downslope, the face and skull bones of a younger individual were also found. These isolated human finds seem to have been washed to where they were discovered, since there is no evidence for human occupation or human interference with the bones in this part of the cave system. Careful mapping, excavation, and dating (including direct radiocarbon determinations on the human fossils) suggest the following sequence of events for the cave system. Cave bears regularly entered the deep cave to hibernate until about 46,000 years ago, with many dying during hibernation. About 46,000 years ago, there was a major collapse, which changed the nature of the cave by opening up a closer entrance. Carnivores such as wolves and the occasional lion now denned there, bringing back the remains of prey such as deer and ibex. About 42,000 years ago, the Oase humans were in the cave, either using it for shelter or perhaps carried there by carnivores, and their remains were then swept to where they were discovered, in one of the periodic floodings that engulfed the cave system.

  An international team of researchers has been studying the Oase finds, and in particular the human jawbone and the separate skull. The jawbone is strongly built but undeniably modern in its well-developed chin. And yet its molar teeth are large, with quite complex cusps, and it has some interesting features toward the back. The ascending ramus of the jaw is extremely broad, and on its inner side there are yet more intriguing traits. On the inside of the back of this jawbone on each side is the mandibular foramen, a hole through which the mandibular nerve travels to the lower teeth. In most living humans and in almost all fossil ones, the foramen is open and V-shaped, as it is on one side of the Oase jaw. But on the other side there is a bridge of bone across the foramen, known as the horizontal-oval (H-O) type. This H-O foramen is present in about half of all Neanderthal fossils, but it is generally rare in early modern fossils and usually only occurs at a level of a few percent in living humans. Accordingly, when found in a smattering of European Cro-Magnon fossils, it has been seen as a marker of possible Neanderthal ancestry, which it certainly could be, given its rarity in preceding African fossils and those from Skhul and Qafzeh. How much its presence is inherited, and how much is associated with having particularly strong jaw ligaments (which are attached to that area of the jaw), is still unclear, and the picture is further confused by the fact that some of the highest frequencies of it in recent populations occur far away from Europe and Neanderthal influence, in places like Easter Island.

  The Oase skull is not Neanderthal-like, but it’s strangely unlike later Europeans too. It’s from an adolescent, of uncertain sex, with the third molars still unerupted but enormous, and with even more complex cusps than in the separate mandible. The forehead retreats a little, but the lack of brows and suprainiac fossa and the flat face and nose shape are particularly non-Neanderthal. However, the back teeth are bigger than those of any modern humans I have seen from Eurasia, living or fossil. In support of his favored Assimilation model, my friend Erik Trinkaus argued that features like the H-O foramen, the relatively flat forehead, and the large molars could all be a sign of a mixed modern–Neanderthal heritage. And indeed, at a date of more than 40,000 years, the Oase humans seem to have been in the vanguard of modern human penetration of Europe, with the maximum potential for encountering Neanderthals. On the other hand, to me, the teeth look unlike those of Neanderthals as well, so where did these enigmatic early Europeans come from?

  At this point we should note that the Oase human fossils have no associated artifacts; even if they were living elsewhere in the cave, only their actual bones were recovered, following redeposition from an unknown location. But given their unusual features and their antiquity—perhaps beyond the age of other European moderns and definite Aurignacian tools—I think they could even have been makers of the mysterious Bohunician industry. This was named after the Czech cave Bohunice, and like the Châtelperronian, its characteristic tools show a mixture of both Middle and Upper Paleolithic elements. The method of manufacture is often the “prepared core” so typical of Middle Paleolithic artifacts in Europe, western Asia, and Africa; in that sense the Bohunician maintains an older tradition associated with both Neanderthals and the earliest modern humans. But there are also many of the blades, end scrapers, and burins (engraving tools) that characterize the European Upper Paleolithic and African Later Stone Age made by modern humans. However, the Bohunician has not, so far, shown any evidence of sophisticated bone or ivory artifacts, or beads.

  So, as with the puzzle of the Châtelperronian, was the Bohunician made by Neanderthals or moderns, or someone in between? It has not yet yielded any diagnostic human remains, but there are interesting clues from its dating and possible origins. The Bohunician was dated by radiocarbon and luminescence methods to about 45,000 years—slightly older than the Oase humans—and certain aspects of the tools and the way they are made link with similarly aged industries in Turkey and the Middle East, as we shall see. Could this signal a previously unrecognized dispersal of modern humans into Europe before the Aurignacian? For me, clues to the origin of the Bohunician and the Oase people are not likely to be found at an older date in Europe—both seem not to have local antecedents and therefore look intrusive. And what was the ultimate fate of the Oase folk? Did they give rise to the succeeding Cro-Magnons of Europe? Or were their pioneering colonization of Europe and their possibly unpredictable encounters with the Neanderthals ultimately in vain, terminated by climatic and environmental catastrophes that soon followed?

  As mentioned in chapter 2, around 39,000 years ago, there was a massive eruption in the volcanic area of southern Italy known as the Campi Flegrei (the “burning fields”), near the Bay of Naples. The region is still active today and includes the Solfatara crater, the mythological home of the Roman god of fire, Vulcan. The eruption was perhaps second in extent to that of Toba in Sumatra during the last million years, and it produced the massive ash deposits known as the Campanian Ignimbrite (CI), which extend for some eighty kilometers. It also produced finer sulphur-rich deposits that spread even farther over an area of some 5 million square kilometers of the Mediterranean and western Eurasia, and it might also have produced a brief volcanic winter. Such a period of global cooling can be caused when increased atmospheric dust and droplets of sulphuric acid reflect sunlight back into space, and finer sulphide compounds may have a longer-term effect if they reach and stay in the upper atmosphere.

  This episode was closely followed by a Heinrich event, a phenomenon first described by the geologist Hartmut Heinrich. During these brief but severe cold events, armadas of icebergs broke off the northern ice caps into the North Atlantic, for still unknown reasons. As they flowed south they melted, chilling the ocean and surrounding lands, and shedding ice-rafted debris to the ocean floor, one of the characteristic signals of these events in deep sea cores. “Heinrich 4” occurred about 38,000 to 39,000 years ago, and it severely chilled Europe, its influence showing in cores as far east as the lakes of Italy and Greece and the eastern Mediterranean.

  Some researchers have even argued that this unusual combination of a volcanic winter, without proper summers for a number of years, closely followed by the chill of a Heinrich event drove many of the changes we can detect in the archaeological record of Europe around this time by either suddenly crashing (bottlenecking) Neanderthal human populations or forcing them to move, interact, and adapt in entirely new ways. In one view this opened the door for modern humans to colonize Europe, and in another interpretation it catalyzed dramatic changes in Neanderthal behavior and biology, converting the survivors into modern humans! I don’t accept either explanation, because we know from Oase Cave in Romania and Kent’s Cavern in England that modern humans were already in Europe before this time, and we know from sites in and beyond Europe that behaviors were already changing significantly. But there seems little doubt that these events would have profoundly affected both the Neanderthal and early modern human inhabitants of Europe. If the pioneering moderns were only in
Europe in small numbers, while the Neanderthals remained in occupation of southern France and the southerly peninsulas of Iberia, Italy, and Greece, it seems likely that both Homo sapiens and their Neanderthal cousins would have suffered attrition. So perhaps the Oase people died out, just as many Neanderthals did at this time (see chapter 2).

  Where did these newcomers come from, before they reached Romania? One clue lies far across Turkey, on its rugged coast, just fifteen kilometers away from the border with Syria. Üçağizli (“Three Mouths”) Cave was discovered and first excavated in the 1980s, and now lies about eighteen meters above the Mediterranean. The sea floor slopes steeply away about five kilometers out, so even with the dramatically lowered seas of the last Ice Age, Üçağizli would never have been far from the coast. The cave deposits cover over 10,000 years, beginning about 44,000 years ago, and they contain many thousands of tools. The earliest of these resemble an industry in neighboring Middle Eastern countries called the Emiran, as well as the Bohunician of Europe, while subsequent tools from around 36,000 years represent something called the Ahmarian, about which more later in this chapter. But the site has many more features alongside the tools, including evidence of both short-term (small fire pits of charcoal) and long-term (huge heaps of ash) human occupation. One level even contains an impressive curved row of limestone blocks, perhaps a low wall, of unknown function.

  An international team, including the archaeologists Steven Kuhn and Mary Stiner, has been excavating the cave since 1997 and has found not only large numbers of flint tools but also numerous bone points—perhaps piercers. Even more extraordinarily, they recovered many hundreds of ornaments made from shells, which must have been strung as beads or pendants. These were probably parts of necklaces or bracelets, and, in one instance, the talon of a vulture had also been utilized. While large shells in the site show signs of being smashed for consumption, the small ornamental ones are usually whole, apart from being pierced, and seem to have been collected from lake shores, rivers, or beaches expressly for the purpose of jewelry. From discarded failed attempts, the shells were probably worked at the site with pointed tools, and the holes were positioned very consistently, while some show signs of rubbing, where they were probably strung on natural fibers. In the case of a genus called Dentalium (tusk shells), these seem to have been collected as fossils from a geologic deposit about fifteen kilometers away and were snapped at intervals to create tube beads. Interestingly, the oldest layers in the cave show a dominance of lustrous Nassarius (tick shells), exactly the kind used as jewelry by much earlier modern humans in Africa and Israel (see chapter 5), suggesting a symbolic tradition running back 50,000 years earlier.

  As we do today, the Üçağizli people probably used their appearance (including their ornaments) as conscious or unconscious symbols of group identity, marital status, and their roles in society. Equally, the use of such symbols implies that the meaning of what they were signaling would be recognized within their communities, and perhaps also when other human groups were encountered (see chapter 5). The cave obviously acted as a bead factory, but we don’t know how significant this was socially to the people of the time. Perhaps it was just a convenient shelter or camp near the Mediterranean, a place where they could carry out the work, or maybe it fortuitously preserved the evidence of what were actually widespread activities better than more exposed locations. But based on the ornaments of modern hunter-gatherers, and what we find in the later Paleolithic sites of Europe, we can guess that these shell beads were only part of the story of display, which could also have involved body paint and clothing.

  Only a handful of teeth remain of the inhabitants of Üçağizli from a presence lasting many millennia. One tooth is reportedly large, but overall they seem to represent Homo sapiens, suggesting that the occupation was indeed by modern humans. The food refuse left at the site shows that many large animals (such as wild goats and pigs, red, fallow, and roe deer, and wild cattle) and also small ones (hare, squirrel, partridge) were processed and consumed there. The diet was supplemented with shellfish, and at times even fish such as bream seem to have been eaten. Many of the stone tools must have been manufactured to kill or process game, and they include spear points and many narrow blades modified into knives, scrapers, and points. Tools and food-gathering behavior mostly show only gradual changes through the cave sequence, suggesting a presence over many millennia. There is one exception, about 41,000 years ago, however, when the inhabitants switched from using hard hammers (for example, cobbles) to soft hammers (probably of bone or antler) to make their tools, giving them greater control over fine working and shaping. Overall, there are signs that the occupations gradually became less episodic and longer in duration, and the food consumed more varied, perhaps indicating the growing abilities of the Üçağizli hunter-gatherers to adapt to their local environment.

  As we saw, physical traces of the inhabitants of Üçağizli over a period of more than 10,000 years are few and far between, although they were almost certainly modern humans. To find further evidence of the people of this period, we need to travel south from the cave, first to Lebanon and then the Nile Valley. As mentioned, the Emiran and Ahmarian industries of Üçağizli resemble those found elsewhere in the Middle East, and one of the key sites, Ksar ’Akil, is in Lebanon, about 250 kilometers farther south. This rock shelter just outside Beirut contains nearly twenty meters of deposits, rich in fossils and artifacts. A Jesuit priest and archaeologist, Father J. Franklin Ewing, first excavated the site in the 1940s, and it has been reinvestigated intermittently since, when the political situation has allowed. The Emiran and Ahmarian levels date from around 42,000 to 35,000 years ago, and the animals hunted were comparable to those found at Üçağizli. There is another major similarity in the presence of many shell beads, but there is one significant extra at Ksar ’Akil: compared with the scattered teeth found at the Turkish site, Ewing discovered the partial skeleton of a child, who acquired the nickname “Egbert.” Unfortunately, in the chaos that has intermittently descended on Lebanon, the original fossil vanished, hopefully only temporarily, but I studied a replica of the child’s skull made by Ewing’s team. It is undoubtedly a modern human child and surely shows us the species responsible for the shell beads in Turkey and Lebanon some 40,000 years ago.

  There are further possible connections in the only North African fossil human of comparable age to Oase, Üçağizli, and Ksar ’Akil: the 40,000-year-old Nazlet Khater specimen from Egypt. This skeleton is of a young man who was deliberately buried in one of the oldest known mines, dug to extract chert rocks for toolmaking, close to Luxor on the Nile. His short and apparently well-muscled frame has many marks of wear and tear in one so young, leading to the suggestion that he might even have been an ancient slave forced to work in the mine; but if so, he seems to have been laid out in a decent burial. His skull is clearly that of a modern human, yet in the slightly retreating forehead, the shape of the face, and the wide ascending ramus of his jawbone, he resembles the Oase fossils. His teeth are not as large, and the poorly preserved inner surface of his jaw seems not to show an H-O foramen. But the tools made from the stones he must have quarried bear a general resemblance to those found in Lebanon, Turkey, and the Bohunician sites of central Europe. So perhaps this gives us a clue as to where the earliest modern people in Europe came from, and their route into Europe from the Middle East, during a brief warm phase about 43,000 years ago. Did people like those at Nazlet Khater and Oase, bearing proto-Bohunician artifacts, travel around the Turkish coastal plains (more extensive then because of lower sea levels) to the Black Sea, and then up the Danube corridor toward central Europe? If they did, it seems that their pioneering long trek might ultimately have ended in failure, and it was the succeeding Aurignacians who next took up the challenge of Europe and the Neanderthals.

  Highly controversial evidence that those Aurignacians met (and maybe ate?) one of the last Neanderthals was published in 2009. The claim came from a detailed study of jaws and teeth found
many years ago in Aurignacian levels at the cave of Les Rois in southwestern France. One child’s jawbone is clearly modern, but the other shows possible Neanderthal features in its teeth, and growth lines on its teeth show a Neanderthal-like pattern of development (see chapter 3). Furthermore, while the more modern of the jawbones shows no signs of human modification, the Neanderthal-like one carries cut marks that suggest defleshing, and possible removal of the tongue. The authors were cautious about whether this represented cannibalism, and considered the alternatives that the cut marks were evidence of symbolic use of the child’s remains as a trophy, or as postmortem treatment before burial. They concluded with three possible explanations for this unprecedented discovery: that the Neanderthal-like jawbone suggests symbolic use or consumption of a Neanderthal child by early Cro-Magnons; that Aurignacian tools were in fact produced by human groups bearing both modern and Neanderthal characteristics, that is, a mixed or hybrid population; or that all the remains from Les Rois represented modern humans, but that some displayed more primitive characteristics than normal in the Cro-Magnons.

  Any one of those three explanations would be important for our understanding of events in Europe about 35,000 years ago, and the first two would be sensational evidence in support of one or the other of the two leading scenarios for the extinction of the Neanderthals that we discussed already: that they were replaced by the Cro-Magnons after a period of coexistence and possible interaction, which might have included direct competition between them; or that the Neanderthal and Cro-Magnon populations interbred and blended with each other during their possible coexistence. However, before getting carried away with these scenarios, we have to remember that the tantalizing second jawbone bearing cut marks is very incomplete, and the authors acknowledged that their identification of it as Neanderthal was tentative (other workers have identified the teeth in it as modern). New studies of the Les Rois fossils are planned, which could even include DNA investigations, and these should certainly help to clarify the picture. And because of the importance of Les Rois, new excavations are taking place there, and further human fossils have already been found. So hopefully this new evidence will help to solve the intriguing mystery of the children of Les Rois—their identity and their fates—in terms of events 35,000 years ago in Europe, and in terms of what they can tell us about human evolution in general. In that respect, it is also interesting to look at events at this time far across the huge landmass of Eurasia, in China.