These are the oldest Homo sapiens fossils ever found in Europe

These are the oldest Homo sapiens fossils ever found in Europe

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These are the oldest Homo sapiens fossils ever found in Europe

A 46,000-year-old tooth and a handful of bone fragments are the oldest direct evidence of our species’ presence in Europe, a recent study reports. They lived and died during an important period of transition, when our species and Neanderthals were meeting and interacting—a period we don’t currently know much about. The dates shed a little light on at least a piece of that eventful time.

Us and them

The last trace of Neanderthals in Europe dates to around 40,000 years ago. Anything very much older than that is almost certainly a piece of Neanderthal culture and made by Neanderthal hands. Anything very much younger than that must have been the work of our own species, long after the last Neanderthals had died out. But for a few thousand years, Homo sapiens and Neanderthals shared a continent.

We’re not sure exactly how long our two species coexisted, and that’s why Bacho Kiro Cave matters so much. At sites without any hominin fossils, archaeologists have to rely on the age of the artifacts if they want to draw conclusions about which species made them. But at Bacho Kiro, archaeologists found fragments of radiocarbon-dateable human bone mixed with stone tools and other artifacts. It’s the Paleolithic version of a smoking gun.

Jean-Jacques Hublin (director at the Max Planck Institute for Evolutionary Anthropology), Helen Fewlass (also of MPI), and their colleagues say it means that certain flint-knapping methods, types of stone tools, and pendants made from bear teeth belonged to the culture of the first members of our own species to settle in Europe, and not to Neanderthals.

“There are similarities in manufacturing techniques used by Homo sapiens at Bacho Kiro and Neanderthals elsewhere, which makes clear that there was cultural transmission going between the two groups,” New York University anthropologist Sarah Bailey, a co-author of the study, said. We could have inferred that cultural tradeoffs must have happened between our species and Neanderthals back then, because that’s what happens any time two groups of people meet: Locard’s Exchange Principle writ large. But we’re still not sure exactly who borrowed which ideas, technologies, and ways of doing things from whom.

Bacho Kiro Cave answers a couple of those questions, but not all of them.

A Pleistocene smoking gun

The handful of bone fragments radiocarbon-dated from 46,790 to 42,810 years old. They lay buried in a layer of rich, dark sediment, mingled with stone blades, bone leatherworking tools, ivory beads and pendants, and the butchered bones of red deer and bison. Most of the stone tools were long flint blades and points made with a technique called retouching.

Similar stone tools, along with similar bear-tooth pendants, have been found at sites across a swath of Eurasia from central Europe to modern-day Turkey, dating to between 45,000 and 43,000 years ago. Archaeologists call the culture they represent “Initial Upper Paleolithic,” which is precise but not very catchy. Because of its age, it hasn’t been clear whether Initial Upper Paleolithic was a Neanderthal culture or a Homo sapiens one.

But this time, the trademark Initial Upper Paleolithic artifacts were unearthed from the same sediment layer as the people who—it’s reasonable to assume—made and used them. Except for the tooth, which was clearly a Homo sapiens molar, the other bone fragments were too small and worn to identify on sight, so paleoanthropologists had to take small samples from each piece and study the proteins that made up the bone.

“Most Pleistocene bones are so fragmented that by eye, one cannot tell which species of animal they represent,” explained Frido Welker, Postdoctoral Research Fellow at the University of Copenhagen and research associate at the Max Planck Institute for Evolutionary Anthropology. “However, the proteins differ slightly in their amino acid sequences from species to species.” The analysis showed that the bones were human, but what kind of human? To narrow it down further, Hublin, Fewlass, and their colleagues sequenced DNA from the tooth and the bones. Those turned out to be the fragmented remains of at least five members of our own species.

On the face of it (if you’ll allow a little flint-knapping pun), that evidence seems to settle the debate about whether Homo sapiens or Neanderthals first developed this toolkit and started wearing bear-tooth pendants. After all, some of the bear-tooth pendants in Bacho Kiro look a lot like the ones found at Neanderthal sites much further west, in France, dating to the last centuries of the species’ existence.

Stone artifacts from the Initial Upper Paleolithic at Bacho Kiro Cave: 1-3, 5-7 Pointed blades and fragments from Layer I; 4 Sandstone bead with morphology similar to bone beads; 8 The longest complete blade.
Enlarge /

Stone artifacts from the Initial Upper Paleolithic at Bacho Kiro Cave: 1-3, 5-7 Pointed blades and fragments from Layer I; 4 Sandstone bead with morphology similar to bone beads; 8 The longest complete blade.

Cultural transmission is a two-way street

“This confirms that Homo sapiens were mostly responsible for these ‘modern’ creations and that similarities between these and other sites in which Neanderthals made similar things are due to interaction between the populations,” said Bailey. In other words, Neanderthals just copied from the more technologically advanced newcomers. And in the case of Initial Upper Paleolithic stone tools and pendants, that seems to be the case.

But culture is a big, complex thing, and when societies collide, it’s almost never true that one just adopts the other’s entire culture. It may not always be an even exchange, but it nearly always flows two ways. For instance, tools at Bacho Kiro included at least one possible Neanderthal invention: a bone tool called a lissoir, used for softening and preparing animal hides.

The oldest lissoir that we know about comes from a 51,000-year-old site in France, where it was found near the skull of a Neanderthal child. There’s no trace of Homo sapiens ever living at the site, called Peche-de-l’Aze I. And if that’s the case, then the members of our species living at Bacho Kiro a few thousand years later may have learned about lissoirs from their Neanderthal neighbors. Around the same time, Neanderthals elsewhere in France were spinning plant fibers into plied yarn 51,000 years ago, which means they probably didn’t learn that from us.

Neanderthals painted horses and hand stencils on the walls of Western Spain’s Maltravieso Cave at least 64,000 years ago; by the time our species arrived in the area 20,000 years later, the cave’s rock had already begun flowing down to cover the already-ancient paintings. And a whopping 114,000 years ago at Cueva de los Aviones, on the southeastern coast of Spain, Neanderthals decorated seashells with red and yellow pigment and strung them as beads or pendants. That’s the oldest known jewelry found anywhere, by a margin of around 20,000 to 40,000 years.

Waves before the flood

The deepest-buried layer in Bacho Kiro cave dates to around 51,000 years ago, and the stone tools it contains are more typical of a culture that’s definitely Neanderthal: sharpened flake tools, made with a knapping method called Levallois, from relatively coarse-grained rock that would have been available near the cave. The first human fossil dates to around 46,000 years ago, and it shows up alongside the first of the long flint blades and bear-tooth pendants.

It’s not the first suggestion that our species had ventured into Europe earlier than 40,000 years ago; Homo sapiens fossils have turned up in sediment layers dating between 45,000 and 43,000 years old elsewhere in the area. But at those sites, archaeologists were dating other artifacts in the same layer, not the bones themselves. The Bacho Kiro evidence is clearly more direct.

And Bacho Kiro suggests that our species had more time to interact with Neanderthals than we previously realized—a few thousand years more. We’re not yet sure what that might tell us about the nature of those interactions, but Bacho Kiro offers some important hints at the larger story. By showing that the awkwardly named Initial Upper Paleolithic culture belonged to our species, the site also tells us that by around 45,000 to 43,000 years ago, Homo sapiens had gained some kind of foothold from central Europe to modern Turkey.

That means Neanderthals and our species were probably in contact much earlier in eastern and central Europe than further west. And that probably explains why Neanderthals seem to have held on for so much longer in western Europe than elsewhere.

But the Homo sapiens at Bacho Kiro may just have been part of an early wave before the final flood of our species into Europe. “Pioneer groups brought new behaviors into Europe and interacted with local Neanderthals,” explained Hublin. “This early wave largely predates that which led to [Neanderthals’] final extinction in western Europe 8,000 years later.”

To be sure, as always, paleoanthropologists need more fossils and more data.

Nature, 2020 DOI:  10.1038/241559-020-1136-3 and 10.1038/s41586-020-2259-z  (About DOIs).

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via Ars Technica https://arstechnica.com

May 15, 2020 at 02:57AM

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