America Before
Page 11
I paused to breathe in the cave air, cool and moist, and to look around, struck by the way the bone-white walls, stained by lichen and covered in the ugly scrawl of recent graffiti that defaced almost every exposed surface, nonetheless gathered about themselves a kind of somber, ancient magnificence. The effect was enhanced by soaring archways leading into the smaller, more intimate East and South Galleries, the side chapels to this prehistoric basilica. I deploy the analogy deliberately because the Denisova Cave system does have a “cathedral-like” feel about it, but I do not claim that it was ever used for religious or spiritual purposes. It may have been, but what the mass of archaeological evidence suggests is that for extraordinarily long periods of time it functioned as a “factory” or “workshop,” and that raw materials were brought here from far-off places to be worked and fashioned.
This became clear during the brief visit we made to the Museum of the Peoples of Siberia in Novosibirsk before setting out for Denisova Cave. Director Irina Salnikova apologized that there was so little for us to see in the Denisova room of her museum, explaining that much of the collection was away at exhibitions or in laboratories for further investigation. What she was able to show us, however, as well as many stone tools at various stages of refinement, from extremely primitive to sophisticated, were some unusual and beautiful pieces of jewelry including pendants featuring biconical drilled-out holes, cylindrical beads, a ring carved from marble, a ring carved from mammoth ivory, and bone tubes perhaps designed to hold bone needles so they could be carried safely.13
Many of the materials employed had been brought considerable distances to the cave,14 and now that I had reached the cave itself I could see all three of the galleries in which they had been found and inspect the open excavation trenches with little tacks and tags left in place to mark the various occupation levels. It was the gaping rectangular trench in the center of the Main Gallery, however—I would guess it was 5 meters deep, 4 meters long, and 3 meters wide—that most clearly displayed Denisova’s amazing time machine of stratification, with distinct Ice Age occupation levels numbered from 9,15 the youngest, all the way down to 20, the oldest, right at the bottom.
The excavation had descended farther here, down to Level 22, but the tacks and tags for these last two lower and older levels, visible on early reports of the progress of archaeology in the cave,16 were no longer present. According to studies undertaken by the excavators, man-made tools and artifacts were found in these two exceedingly ancient layers, dated by radiothermoluminescence to between 155,000 and 282,000 years ago.17 “The lithic [stone] industries recovered from strata 22 and 21 are characterized by Levallois and parallel strategies of stone reduction; the tool kit is dominated by sidescrapers and notch-denticulate tools.”18
I knew that artifacts together with Neanderthal and Denisovan remains had been recovered in the excavations in all three galleries across multiple Paleolithic occupation levels. That morning, however, my focus was particularly on Level 11 in the East Gallery, where certain unusual and distinctive tools and pieces of jewelery had been found.
Some of these had the archaeologists scratching their heads.
USUAL THINGS AND UNUSUAL THINGS
ANNOYINGLY, I HAD BEEN UNABLE to view these special items during my visit to the Museum of the Peoples of Siberia. But I knew from my research that they’d been retrieved, together with other more “normal” and “usual” objects, from an almost exclusively Denisovan occupation level of the East Gallery, nominated Level 11 by the archaeologists and dated to the Upper Paleolithic between 29,200 and 48,650 years ago.19
After the first Neanderthal skeletal remains were identified in Europe in the nineteenth century it was, for a very long while, one of the fundamental unquestioned assumptions of archaeology, a matter taken to be self-evidently true, that other “older,” “less-evolved” human species never attained, or even in their wildest dreams could hope to aspire, to the same levels of cultural development as Homo sapiens. During more than a century of subsequent analysis, and despite multiple additional discoveries, the Neanderthals continued to be depicted as nothing more than brutal, shambling, stupid subhumans—literally morons by comparison with ourselves.20 Since the beginning of the second decade of the twenty-first century, however, and with increasing certainty as the evidence has become overwhelming, a new “image” of the Neanderthals as sensitive, intelligent, symbolic, and creative beings capable of advanced thought processes and technological innovations has taken root among archaeologists and is set to become the ruling paradigm.21
There should be no objection in principle, therefore, to the notion that the anatomically archaic Denisovans, a close genetic “sister species” to the Neanderthals, might have been capable of creating the sorts of tools and symbolic artifacts that, a few decades ago, would automatically have been assumed to be the work of anatomically modern humans.
Yet a difficulty arises.
Among the more “unusual” and “unique” items excavated from the Paleolithic deposits within the entrance zone of the East Gallery, specifically from Level 11.1,22 were two broken pieces of a dark green chloritolite bracelet. It would have measured 27-millimeter wide and 9-millimeter thick when intact, with an original complete diameter of about 70 millimeters.23 A detailed use-wear analysis of the bracelet was undertaken and revealed something odd: “This artifact was manufactured with the help of various technical methods of stone working including those that are considered non-typical for the Paleolithic period. … The bracelet demonstrates a high level of technological skills.”24
In their detailed scientific analysis published in the journal Archaeology, Ethnology and Anthropology of Eurasia, A. P. Derevianko, M. V. Shunkov, and P. V. Volkov draw our attention, in particular, to “a hole drilled close to one of the edges” of the bracelet and report that “drilling was carried out with a stable drill over the course of at least three stages. Judging by traces on the surface, the speed of drill running was considerable. Vibrations of the rotation axis of the drill are minor, and the drill made multiple rotations around its axis.”25
They therefore conclude that the bracelet “constitutes unique evidence of an unexpectedly early employment of two-sided fast stationary drilling during the Early Upper Paleolithic.”26
This is a big deal!
What the investigators are getting at is how peculiar and misplaced in time the bracelet seems to be. It is not simply that it shows the application of skills and technologies that are “unique for the Paleolithic”27 (i.e., to state the matter plainly, skills and technologies that had never before been seen in a Paleolithic context in any excavation) but also that at least some of these skills and technologies, like “stationary drilling” with the use of a bow drill that does not leave signs of drill vibration,28 would not be seen again until the Neolithic many thousands of years later. The bracelet thus refutes what the authors describe as “a common assumption” held by archaeologists that “stone drilling originated during the Upper Paleolithic, but gained the features of a well-developed technology only during the Neolithic.”29
So not only was this curious bracelet unequivocally the work of anatomically archaic human beings—the Denisovans—but also it testified to their mastery of advanced manufacturing techniques in the Upper Paleolithic, many millennia ahead of the earliest use of these techniques in the Neolithic by our own supposedly “advanced” species, Homo sapiens. Also made crystal clear was the realization that the Denisovans must have possessed the same kinds of artistic sensibility and self-awareness that we habitually associate only with our own kind—for there can be no doubt that very real, conscious, aware, and unmistakably human beings had interacted with this bracelet at every stage of its conception, design, and manufacture, all the way through to its end use.30
Though the outward structure of Denisovan skulls might have been rather different from ours (predictable for a “sister species” to the Neanderthals), the sense of style, design, and personal adornment manifested in the b
racelet seems completely modern, and archaeological reconstructions show it to have been a beautiful thing.
Reconstruction: The bracelet formed a torque, slipped sideways onto the wrist.
Its calculated diameter of just 70 millimeters when intact would have made it “practically impossible to put even the thinnest hand into it.”31 The most likely solution, however, since it undoubtedly was worn, is that this stone bracelet originally took the form of a torque—not fully circling the wrist, but with a section removed: “The tips of the bracelet were likely cone-shaped. Such a shape of the ends of the bracelet makes it easy to put on a hand tangentially. … Judging by the size of the artifact and the signs of extensive use-wear on the interior surface close to the end, the bracelet sat tightly on the wrist.”32
These signs included evidence of “long contact of the interior surface with human skin”33 and, more intimately, “remains of … fat from human skin”34—details that reach across the ages and forge a poignant sense of connection. Indeed it dilates the imagination to contemplate the identity of the person this bracelet was originally made for, who certainly—given the estimated diameter—must have had slim and graceful wrists to wear it well. It is unlikely to have been the property of a child because of its rarity, artistry, and high value. As the investigators report: “It brightly shimmers in broad daylight and reveals a rich play of hunter green shades in the light of a campfire. The bracelet was hardly an everyday item. Fragile and elegant, it was apparently worn on very special occasions. Given the utmost rarity of the material and the thorough finish, the bracelet was a prestigious ornament attesting to its owner’s high status.”35
All in all, it seems a fair speculation that the slim-wristed person who owned this bracelet so many millennia ago was a woman. If so, whoever she was, whatever position of status she may have occupied, we can also guess that she had quite an eye for beauty and a whimsical sense of style. A nice additional detail of the bracelet is that for a long while the drilled hole held a leather strap from which was suspended a pendant.36 Though neither the pendant nor the strap has survived, their presence left unmistakable polish marks around the hole: “The polished area is limited suggesting that the pendant was rather heavy and caused a strictly set amplitude of oscillation of the strap. The outlines of the polished area suggest the ‘up’ and ‘down’ sides of the bracelet and allow us to assume that the bracelet was worn on the right arm.”37
Again, there is that sense of contact, of intimacy, as though we’re separated by no more than a hair’s breadth from this ancient human. It must be admitted, however, that even here we’re speculating. We might not be dealing with a single individual at all. The bracelet might instead have been a treasured heirloom, passed down from mother to daughter across many generations.
Whatever the truth is, it was eventually broken—not once but twice. On the first occasion the break was evidently accidental and it must still have been cherished because it was carefully repaired, literally put back together again, with some effective but as yet unidentified form of glue.38
The second occasion was very different. It appears that the bracelet was deliberately smashed—we can only guess at the motive—“by a blow against a hard surface.”39
THE EYE OF THE NEEDLE
THE LOWER PART OF LEVEL 11 dates back, as we’ve seen, to around 50,000 years ago, but the bracelet was found in the upper part, officially designated Level 11.1 and provisionally dated to the Upper Paleolithic about 30,000 years ago40—making it, because of its “Neolithic” characteristics, roughly 20,000 years ahead of its time.41
The reader will understand, therefore, why it was one of the frustrations of our trip to Siberia in September 2017 that I was not able to see, nor Santha to photograph, this enigmatic, intriguing, and profoundly out-of-place bracelet. Under normal circumstances it is kept at the Museum of the Peoples of Siberia in Novosibirsk, but as luck would have it, during our short visit there, it was out of town—indeed not only out of town but out of Siberia, out of Russia, and in fact in Paris, where it had been on show in an exhibition. When I said we’d travel there to see it, Irina Salnikova told us that it was no longer on public view and was under investigation by “an international team of archaeologists.”42
Gone with it was a second anomalous object, an exquisite bone needle 7.6 centimeters in length, with a near-microscopic eye less than 1 millimeter in diameter drilled out at the head.43 Slightly curved like a modern surgical suture needle, it was excavated from the lower part of Level 11 (Level 11.2) of the central chamber in the summer season of 2016.44 No detailed analysis had been published before my visit to Novosibirsk in September 2017, but there was some coverage in the Russian media when the discovery was announced. “It is the most unique find of this season, which can even be called sensational,” commented Professor Michael Shunkov, coauthor of the report on the bracelet and director of the Institute of Archaeology and Ethnography at the Russian Academy of Sciences.45 His colleague Dr. Maxim Kozlikin added, “It’s the longest needle found in Denisova Cave. We have found needles before, but in younger archaeological layers.”46
He was referring specifically to the upper part of Level 11 where the bracelet was found and where, indeed, other smaller bone needles had also been excavated some years before.47 They, too, have fine drilled-out eyes of the type more usually seen in Neolithic than in Paleolithic deposits and provided grounds for skeptics to suggest that the Denisovan dates might have to be revised.48 The idea was floated that both the bracelet and the small needles must in fact be of Neolithic provenance but had somehow migrated downward through the deposits to end up in Level 11.1—a stratum, from the skeptical point of view, in which they were “obviously” too advanced and “untypical” to belong.
What put an end to such speculation was the discovery of the longer, even finer and more technically perfect needle in 2016 and its location not in the upper—younger—part of Level 11 near its contact with Level 10, but instead in the much older lower part near its contact with Level 12. As we’ve seen, this lower part of Level 11 has been dated by accelerated mass spectrometry to around 50,000 years before the present49 (although it may be more ancient, given that 50,000 years is the limit of radiocarbon dating).
By the second half of 2016, therefore, far from proving younger as some had expected, the mysterious artifacts of Denisova Cave were beginning to look like they were much, much older. This impression was confirmed in 2017 with a shocking announcement. Level 11 had been reassessed and its various internal strata reexamined and re-dated. The result of these new investigations was that the bracelet was no longer thought to be 30,000 years old as had originally been supposed, but 50,000 years old!50
This exquisite bone needle 7.6 centimeters in length, with a near-microscopic eye less than 1 millimeter in diameter drilled out at the head, was found at Denisova Cave in 2016. PHOTO: INSTITUTE OF ARCHAEOLOGY AND ETHNOGRAPHY, SIBERIAN BRANCH, RUSSIAN ACADEMY OF SCIENCES.
A year later the Siberian Times published speculation that it might be even older—perhaps as much as “65,000 to 70,000 years old.”51
Professor Shunkov did not welcome the speculation and pointed out that the great antiquity of the bracelet was already a matter of global significance, with immense implications for the way archaeologists look at the past.52 He wasn’t about to commit to an older date before all the relevant experts had reached consensus. “Until then, I will refrain from saying anything,” he explained, adding that some data was “ambiguous” and required clarification. “If or when we agree, we will have to prepare a publication first.”53
I could understand his caution. It was the same sort of caution, for pretty much the same reasons, as Tom Deméré had felt for so long before presenting his controversial evidence and conclusions about the Cerutti Mastodon Site in the pages of Nature. With discoveries like these that have the potential to disrupt years of comfortable scientific consensus it pays to take care, and to prepare the ground, before you go public.
&nb
sp; Persistent rumors filter out of paradigm-busting new discoveries concerning the Denisovans and “multiple big headlines coming up.”54 Meanwhile that beautiful and haunting cave in the Siberian Altai was still, as I write these words in 2018, the only place on earth where physical remains of Denisovans have been confirmed.55 Those so far recovered are few in number, but such are the wonders of genetic science that the fingertip we spoke of earlier, some teeth, some additional bone fragments, and even some dust from the cave floor allow us to be quite sure that Denisovans were in occupation here at least as early as 170,000 years ago and that they came back 110,000 years ago and again around 50,000 years ago.56
Just like the Neanderthals who overlapped with our ancestors and interbred with them, so, too, the Denisovans overlapped the Neanderthals and interbred with them while also, again like the Neanderthals, interbreeding with anatomically modern humans. Viable offspring capable of reproduction resulted from all these liaisons and in August 2018, Denisova Cave obliged yet again by yielding up a bone fragment, more than 50,000 years old and in sufficiently good condition for genome sequencing. It turned out to have belonged to a female, about 13 years of age, who had a Neanderthal mother and a Denisovan father.57
In consequence of such liaisons it’s a tricky business, tens of thousands of years later, to unravel the tangle of inheritance—with gene flow going in both directions between Neanderthals and Denisovans, Neanderthals and anatomically modern humans, and Denisovans and anatomically modern humans. Thus, where Denisovan DNA is found in human populations today (to give just a single example of the sorts of difficulties faced), researchers must be alert to the possibility that it may not have come directly from a Denisovan but via a Neanderthal who had inherited DNA from an earlier tryst, perhaps dozens of generations back, between a Neanderthal and a Denisovan. Multiple other bewildering combinations are also possible, but using powerful computers geneticists are able to disentangle this cat’s-cradle of intertwining genes and lives.