What happened to the Neanderthals?
It's one of the biggest mysteries in archaeology. Now, researchers are a little bit closer to understanding the tumult that might have rocked the Neanderthal world in the millennia leading up to the arrival of modern humans.
A team of archaeologists excavating a “workshop” where Neanderthals made stone tools 45,000 years ago found evidence suggesting that a previous culture of Neanderthals disappeared thousands of years before those toolmakers arrived. Findings from the dig at Aranbaltza in Basque Country, Spain, are published Wednesday in the journal Science.
Lead author Joseba Rios-Garaizar tells IE the findings show that "Neanderthals have a history" that's easy to overlook.
“They experienced historical and demographic changes," he says.
The researchers came to their conclusions after discovering drastic changes in the style of craftsmanship used to make Neanderthals’ most advanced and distinctive technology: stone tools.
Neanderthals called the same place home for tens of thousands of years
The archaeological site at Aranbaltza was first uncovered in 1957, in what was then an active sand quarry. Archaeologists have since realized that Aranbaltza is home to at least three distinct sites. The oldest contains evidence of settlements that date back roughly 100,000 years. In the next-oldest site, archaeologists have found what's left of fireplaces and (probably) structures built by resident Neanderthals roughly 50,000 years ago.
The new paper describes an excavation at the newest site, which was occupied as recently as 43,000 years ago. The researchers didn't find dwellings. Instead, they uncovered the remnants of a stone tool workshop that was littered with 5,686 pieces of rock. Collectively, those lithics (as archaeologists call the stones) tell a story of social change and standardized manufacturing.
Here's the big surprise: the Neanderthals that made those tools seem to be a completely different group from the Neanderthals that lived in almost the exact same location several thousand years before.
But they weren't all from the same lineage
The artifacts at the older sites show the residents were “basing their technology in flake tools,” Rios-Garaziar says. To make one of those, a Neanderthal would “get a nodule of flint or another rock, and hit it [to] get a flake, which is something [they could] use for cutting or scraping.”
Evidence from across Europe shows this was a common way of making tools for tens of thousands of years. But as Neanderthals approached extinction, some groups innovated new ways of making what they needed.
“At the end of the middle Palaeolithic, something changed in Europe," Rios-Garaziar says. "In the center of France, some Neanderthals… left the flakes [behind] and started making blades."
Some of the earliest evidence of this change was found in caves in Châtelperronian, France. The style of toolmaking is so distinctive that archaeologists call it the Châtelperronian "technocomplex," even when it's found in other places.
When they excavated the most recent site at Aranbaltza, the researchers behind the new study found more than 5,000 pieces of stone that suggest the most recent Neanderthal occupants were using that blade-making technique rather than an updated version of the local tool-making tradition found in older settlements in the same location.
Differences in tools reveal more something more profound
The difference between flakes and blades might seem extremely subtle, but the styles of stone tools (and whatever can be inferred about the manufacturing processes used to make them) are some of the relatively few sources of evidence archaeologists have for understanding some of our closest relatives.
Rios-Garaizar says the different styles are representative of distinct “cultural traditions” that researchers have identified by noting differences and similarities in the artifacts that have been dug up at Neanderthal settlements across Europe. These traditions don't suggest different Neanderthal civilizations, but they do show that settlements separated by hundreds of miles or (in some cases) tens of thousands of years were “linked," he says.
“They share the same culture, the same technological choices, the same way of life. Probably they also share genes,” Rios-Garaziar says.
The researchers think the older group of Neanderthals disappeared thousands of years before the Châtelperronian group arrived because the newer site contains practically no artifacts that might have been made using the older technique. The older remains and the more recent ones are also separated by an “archaeologically pristine” layer of Earth, which suggests that no tools were made at all for an extended period of time.
Why did these separate groups end up in the exact same place if there weren't any direct connections between them? It might seem like a coincidence, but the overlap probably comes down to the local geology. Aranbaltza is "close to a source of very good-quality flint," Rios-Garaziar says.
With the collapse of the earlier population of Neanderthals, the Châtelperronian group would have had easier access to that important resource. The demise of the new arrivals — they lasted only a few millennia — might have made room for another wave of great apes.
“Imagine if the same thing [was] happening when modern humans enter Europe,” Rios-Garaizar says.