Геном последнего неандертальца «Торина» раскрыл тайны культурного разрыва и исчезновения вида

Ludovic Slimak has spent decades in the caves once inhabited by Neanderthals, uncovering their worlds. In the process, he has transformed what we know about the very last Neanderthals to have existed, thanks to remarkable discoveries at a small cave in France called Grotte Mandrin. Located next to the mighty Rhône river – once a major migratory route for bison, horses and deer – the cave was inhabited by different groups of Neanderthals and Homo sapiens over a period of 80,000 years as they followed various animal herds. This makes Grotte Mandrin a time capsule of this lost society. It is littered with so many flint tools and fossilised bones that visitors must walk barefoot to minimise damage to the prehistoric treasures buried in the sediment, awaiting discovery by the ongoing excavations. Central to Slimak’s ideas about the last Neanderthals is a 42,000-year-old skeleton he found by chance outside the cave entrance. Incredibly, one of its teeth still contained the individual’s DNA, allowing its genome to be sequenced from a chip, an analysis that reveals startling new clues about the species’ extinction. Advertisement New Scientist met Slimak, who is based at the University of Toulouse in France, at Grotte Mandrin to find out his thoughts about whether Neanderthals really were so different from us – and to smell the odours of prehistoric BBQs still trapped on the rock from the cave walls. (This interview has been edited for clarity and brevity. You can watch the video below.) Alison George: Why is Grotte Mandrin so special? Ludovic Slimak: It’s a tiny cave, but you have a record of the fossilisation of something unique – the very last moments of the Neanderthal population. There’s a very rich record here of human occupation at the site. From 110,000 years ago, Neanderthals came regularly into the cave, and we also have two phases of early Homo sapiens, one at 54,000 years ago and one at 42,000 years ago. At certain moments, both Neanderthals and H. sapiens shared the territory, and they could have even shared the cave. You have a kind of sandwich of occupation between two very distinct humanities, and this is unique in Europe. The end of the archaeological record here, 42,000 years ago, is a pretty exciting period, because it’s when you have the very last Neanderthals, and you have an important migration of H. sapiens across all of continental Europe. You’ve referred to the cave as a prehistoric Pompeii. What are the similarities? Here in the Rhône valley, there is a strong wind coming from the north, called the mistral, which takes sand and silt from the Rhône river and deposits it in the cave, so it’s like Pompeii, but with no catastrophic events. People came here, left their tools, fireplaces and bones, and then it was filled with silt and sand and fossilised. We therefore have a kind of series of miracles because of the position of the cave. It is an incredible time capsule. Is that why we have to take our shoes off when walking here? Everything is very fragile and very well preserved in the cave. When you dig here, it is immediately very rich, and you quickly see archaeological material appearing. So, we have to walk barefoot on the sacred land here! The odours from the ancient occupations of the cave can still be smelled today. When people came in the cave, Neanderthals or H. sapiens, they made fire and the cave became black with soot. Now [on the cave floor] you have millions of soot-covered fragments that have fallen from the vault. Some of them still have the smell not only of the fire, but of the grease of the mammals – bison, horse – that were burned in the fire. So, when you scratch the soot, you have a strong smell of the fat of the animals still fossilised in it. In 2015, you discovered a remarkable Neanderthal fossil at Grotte Mandrin. Tell me about that. I had been working here for 25 years when I discovered that. He was on the floor, perfectly preserved. We just brushed below the leaves and the teeth appeared on the soil [surface]. I was stupefied. Just like that, he was on the floor. It was like encountering the last Neanderthal while walking in the hills. It was incredible. You named this Neanderthal Thorin, after a dwarf character in J. R. R. Tolkien’s novel The Hobbit. Why? That is a world where you have dwarves, you have elves and you have humans – so you have very distinct populations that don’t understand the world in the same way. That was also the case 50,000 or 40,000 years ago when you had Neanderthals, Denisovans, Homo floresiensis… You have plenty of different populations. Thorin, here, is one of the last Neanderthals. And Thorin from Tolkien is one of the last dwarf kings under the mountain. It’s the end of the lineage. How long ago did Thorin live? It’s very likely it was at one of the very last occupations of the cave [by Neanderthals], somewhere around 42,000 years ago, at the moment when a wave of H. sapiens arrived. The excavation of his remains has been painstaking. The bones were in very loose sand. In order not to disturb their position, we decided to take tweezers and extract the sand grain by grain. It’s taken 10 years to excavate a very tiny area. So far, we have found 31 teeth – which is maybe the most complete series of teeth known of Neanderthals – and we have fragments of the skull and mandible [lower jaw bone] and elements of the left-hand phalanges [finger bones]. The archaeological context around Thorin is exceptionally dense and potentially very informative, so we want to ensure that every element is recorded before we [excavate] any further remains. We are advancing slowly and progressively so that nothing in his context is lost. What do we know about Thorin and his group? What we see is a tiny hominin group of maybe 20 or 30 people – two, three, four families living all together. They were hunter-gatherers, a nomadic population that ate mainly horse, bison and deer, but also birds and fish. We have no evidence of cannibalism [in this population], but in the Rhône valley, in [more ancient periods], we know we have cannibals. A chip from Thorin’s tooth unlocked more of his secrets, because his DNA was found in it. That opened up so much. I was astonished. We had searched for DNA for 10 years, but had found none in Grotte Mandrin. Working on his DNA – it has a Y chromosome, so we know he’s male – we realised that not only Thorin, but all his group were very distinctive. They were an unknown population of late Neanderthals that had spent something like 50,000 years isolated from other “classic” late Neanderthals all over Europe. So, this is not simply the discovery of a body – which is very important, and you have a lot of emotion when you find that. But it’s that, with the DNA, we begin to draw the history of this specific population. It was an ancient population that we thought disappeared more than 100,000 years ago. This rewrites key issues in our understanding of who the Neanderthals were and the process of their extinction. Tell me more about these previously unknown Neanderthals. What is interesting is not that it’s only a tiny group… it is something much more complex. It is very likely that Thorin’s population was, in fact, pretty large. There is DNA evidence linking Thorin to Neanderthals from Gibraltar, and also from Poland and Belgium. But this is what is fascinating: they didn’t exchange genes with the classic Neanderthals, so this means that they understood that they were not like them. We couldn’t imagine that there could have been such a deep divergence among the Neanderthal populations. So, it wasn’t necessarily a case of physical isolation – they didn’t mate or interact because they were culturally distinct. What other insights do we have about the last Neanderthals? The Neanderthals and H. sapiens that came here before the arrival of Thorin’s group crossed the Rhône very regularly. We know this from the flints they used and also from the isotopes in their bones. But this stopped when Thorin’s population came to the cave. Then, for 10,000 years, we don’t have any evidence that these people crossed the Rhône, which is incredible because it’s just there, at the middle of the territory. After H. sapiens came [around 54,000 years ago], there is a deep shift in the territories, and suddenly Thorin’s population don’t mix and don’t exchange between the two sides of the big river. Suddenly, there is a border, and it’s not a physical border. It’s during an ice age, so for maybe eight months of the year, it’s frozen, so it’s likely that we have a cultural border, something new that appears and that never appeared before. It shows deep isolation in what is not at all a marginal refuge zone, but one of the great natural migratory corridors of western Europe: the vast Rhône corridor, the central artery linking the Mediterranean to northern Europe. Why does this isolation matter? Isolated populations can be highly vulnerable when territories contract or connections between groups break down. We don’t see that for H. sapiens, for whom it was very normal to exchange a lot of genes [with other groups]. We had a lot of contacts; we built social networks that were very important. Neanderthals used to be thought of as unintelligent brutes, but more recently this view has radically changed, with many researchers arguing that they were remarkably similar to us. But you disagree with both these views, don’t you? The question isn’t whether Neanderthals were inferior or superior to H. sapiens. The good question is: did Neanderthals and H. sapiens understand the world in the same way? You have been digging into this by looking at the tools they made. The way they interact with the raw materials to produce their tools and their weapons is very distinctive between the two populations. With H. sapiens tools, there’s a very clear normalisation and a strong standardisation. The tiny points they made for projectiles are made in exactly the same way, so they are identical to a precision of a few millimetres. They are following strict rules in their heads and are super-efficient. Neanderthals are more creative and produce tools and weapons that are all unique. There’s no normalisation. So, I think, in the deep mind of the Neanderthal, you have a hyper-creative humanity. This tells us that their minds worked differently to our minds. There were two very distinct intelligences. The Neanderthal was super smart, too, but understood the world in a very different way. Could these differences have led to the demise of the Neanderthals, but not in the way we might think? We know that the early H. sapiens who came to Grotte Mandrin had bow-and-arrow technology, which will certainly make an important difference. It’s then much easier to hunt. You can bring a lot of protein back home, and it’s not as dangerous. The weapons of Neanderthals are heavy, hand-cut spears, which means that, when hunting bison, you need to be in direct physical contact with that animal. And if there were a conflict, then there would have been a kind of superiority in terms of lethality by H. sapiens – but I don’t think it works like that. If there wasn’t conflict and war, what made the H. sapiens successful in the end? They were very different in terms of organisation of the group and the ability to feed a lot of children. If it’s easy to bring back protein, and if you don’t die when you go to hunt bison, you can have more children. Then you have the question of the size of the group that you can feed. If you are a Neanderthal, hunting with a hand-cut spear, it’s likely that the size of your group is limited – you can’t ensure enough protein for a very large group. This changes the game totally. So H. sapiens groups bred more and could sustain larger societies with denser populations, and thus found it easier to survive. Is that how you think things played out? There was no big event where H. sapiens came in and killed everything. And it wasn’t due to a catastrophic event like volcanoes, explosions, radiation from space, climate change. Neanderthals could have continued for a very long period because they were absolutely adapted. But they were less efficient. You also think a kind of societal collapse was triggered in Neanderthal groups after their encounter with the sophisticated new arrivals in their territory – a bit like you could imagine happening today if we encountered super-advanced aliens that did everything better than we can. In the encounter between Neanderthal and H. sapiens, it’s as if there was an obsolescence in the Neanderthal way of life, their way to be human. A big genetics study of the late Neanderthals from June this year showed that many groups weren’t as inbred as we thought and seem to have had relatively large networks. What are your thoughts about this research? Its clearest result is that the close-kin mating previously documented at Chagyrskaya [a cave in Russia] cannot be treated as a universal Neanderthal condition. The north-western European Neanderthals were less inbred and belonged to larger or better-connected populations. But their overall genetic diversity remained very low compared with that of modern humans. The study therefore weakens one particular explanation for Neanderthal extinction: a progressive genetic deterioration caused by increasing inbreeding. Ancient caves, human origins: Northern Spain Discover some of the world’s oldest known cave paintings in this idyllic part of Northern Spain. Travel back 40,000 years to explore how our ancestors lived, played and worked. From ancient Paleolithic art to awe-inspiring geological formations, each cave tells a unique story that transcends time. Does your work on the Neanderthals’ demise ever make you sad, after working with them for so long? In my book The Last Neanderthal, I explained that I was very sorry, because it is a sad book. There’s no good ending. On a more optimistic note, do you think that we are likely to uncover even more “lost” Neanderthals like Thorin’s group? Yes. How many could there be? Three? Four? Five? We don’t know. There are very few sites with good preservation of the late Neanderthals. So maybe we will have to wait 50 years to have [another] Thorin appear in Europe. It’s fantastic because now we begin to be able to open the box and have a look, and what we see isn’t what we expect.