Tuesday, April 05, 2022

Neanderthals Went Extinct in Iberia, and Were Replaced – by Other Neanderthals

Armed with advanced tools, Neanderthals may have been able to reconquer territory they had abandoned 1,500 years earlier – but not for long



Excavating the open-air late Neanderthal site, Aranbaltza II
.Credit: Joseba Rios


Ruth Schuster
Apr. 5, 2022 

When did the Neanderthals die out once and for all? Some argue they never did because our ancestors mixed with that subspecies, so bits of their genome live on. The fact remains that you can’t meet a Neanderthal because they are gone, forever more. But one question is the manner of their passing. Now, a new paper posits that the different stone tool technologies at a site in northern Spain indicate migration by Neanderthals, and population replacement of Neanderthals – by other Neanderthals.

For whatever reason – and we shall get to that – by about 45,000 years ago Neanderthals using Middle Paleolithic stone technology seem to have disappeared from Cantabria, including from the open-air Northern Iberian Peninsula site called Aranbaltza II, write Joseba Rios-Garaizar of the Archaeology Museum of Bilbao and colleagues in PLOS One.

There is a “sterile” period, a gap, in the archaeological record there. And then, 1,500 to 1,000 years later, more Neanderthals arrived and replaced them.

These new Neanderthals were armed with more advanced, finer tools known as the Châtelperronian technology, the team posits. Châtelperronian flint tools have a distinctive single cutting edge and a curved back.

A map showing Neanderthals in Iberia.Credit: PLOS ONE

The archaeological layers – Middle Paleolithic; nothing; Châtelperronian – are distinct, the archaeologists write. Moreover, this is far from the only hominin site in the region where Middle Paleolithic and Châtelperronian layers are distinct, showing no continuity.

Neanderthals at work

The Neanderthals-replacing-Neanderthals theory is based on stone tool discoveries at Aranbaltza II, an open-air site (an area clearly used by hominins that is not in a cave or rock shelter). A huge number of tools was found there: in fact, the archaeologists suspect that Aranbaltza II was a Neanderthal stone-working factory, partly because it’s close to a flint outcrop.

In short, this isn’t where the Neanderthals lived, they suggest: it was their industrial zone.
Separately, archaeologists have reported on Neanderthal-era hunting camps and cave dwellings in the region.

Unfortunately, no bones have been found at Aranbaltza II that could have shed a more categorical light on the human species involved, because the soil of Cantabria is too acid for preservation, Rios-Garaizar explains.

Much of this remains controversial, including the contention that Neanderthals were the inventors, the authors, the manufacturers of Châtelperronian-type tools, which so far have been found in France and northern Spain dating to a range of about 44,000 to 40,000 years ago. Not everybody even agrees that there is such as thing as a distinct Châtelperronian industry. And among those who accept its uniqueness, some suspect sapiens involvement, influence, or actual authorship of these tools.



Studying tools from Aranbaltza II in the lab.Credit: Joseba Rios

(The name “Châtelperronian” derives from the site where it was first identified as a distinct industry: Châtelperron in central France, where it was preceded by the Mousterian industry.)

We are pretty sure that anatomically modern humans, we Homo sapiens lot, had reached Bulgaria by 45,000 years ago – the remains uncovered at Bacho Kiro leave little room for doubt. So if sapiens had reached Spain too by that time, could they plausibly be responsible for the Châtelperronian tools found at Aranbaltza?

We do not know but, Rios-Garaizar says, the thinking is they got to western Europe “a little bit” later, definitely by 42,000 years ago. So he remains confident that the Châtelperronian assembly found in northern Spain is of Neanderthal origin.

To shore up that argument, previous work – including paleo-protein analysis – at the site of Arcy-sur-Cure in north-central France indicates Neanderthal authorship of the Châtelperronian techniques, Rios-Garaizar points out.

So for the purposes of this article, let us assume that the occupants of Aranbaltza were Neanderthals, whether post-hybridization with sapiens or not; and that Neanderthals were indeed the party responsible for bringing Châtelperronian technology to the world.


A Chatelperronian flake from Aranbaltza.Credit: Joseba Rios

If so, what happened at this open-air site in Spain tens of thousands of years ago?

Howling storms

If we assume that all the personalities involved in this story of prehistoric Aranbaltza are Neanderthals, then the presence of Mousterian stone technology, replaced a millennium later by Châtelperronian, suggests that the first group of Neanderthals went extinct. Other Neanderthals, late Neanderthals, arrived 1,500 to 1,000 years later, likely migrating from Aquitaine, southwestern France, the team suggests.

Does the cultural change – in stone technology – necessarily translate into Neanderthal migration? Not in the mind of Israeli anthropologist Prof. Israel Hershkovitz, an expert on that era: it’s an interesting speculation but there’s no evidence for it at this point, he argues.

That said, there is no argument that hominin species had wanderlust; various types were leaving Africa as much as 2 million years ago and quite speedily reached the farthest edges of continental Asia. Also, in 2020, separate work published in the Proceedings of the National Academy of Sciences shows Neanderthal migration from Bavaria to southern Siberia. That thesis is based on similarity in tools at specific sites in the two regions, and on DNA analyses of Neanderthal bones and sediments from the Siberian cave Chagyrskaya – which show the Neanderthals there were significantly different from other Neanderthals in Siberia living in Denisova Cave.


Sample of the many tools found at Aranbaltza.Credit: PLOS ONE

Apropos of which, Denisovans – the cousins of Neanderthals – are also believed, based on genetic evidence, to have dispersed widely in central and eastern Asia, even if proven bone evidence for them is extremely scanty: only in Siberia and Tibet. The extraordinarily high component of Denisovan DNA in indigenous Filipinos today is otherwise hard to explain.

So it seems Neanderthals would and did get about, and if Rios-Garaizar and his colleagues are right about the cascade of events at Aranbaltza, localized extinctions and replacements may have played a role in the ultimate total extinction of their species, which would be pretty soon after Châtelperronian technology appeared.

There is no consensus for the timing of the Neanderthals’ extinction, but most agree they “barely” crossed the 40,000-year boundary, possibly surviving until about 37,000 years ago in some places, Rios-Garaizar says. Châtelperronian was one of the last technological and cultural expressions of Neanderthals.

No, their work cannot indicate which of the postulated causes – endogenous, climate change, we nice folk moving into the neighborhood – were responsible. But if Neanderthals went extinct in Cantabria for a thousand-plus years and then came back, we can suspect the howling vagaries of climate at the time were involved.

In any case, by this time in their story, the Neanderthals were in decline, their small groups under stress – various reports show evidence of pathologies suggesting they were procreating through incest in the absence of more appealing options; that at least some were stricken by kuru after eating the brains of their own dead; that sapiens appeared with its mega-kicky brain – not as big as a Neanderthal’s, but somehow qualitatively improved in a way that led us to create figurative art while they did not; or simply that we sneezed on them and infected them with germs to which they had no natural immunity.


A Chatelperronian flake from Aranbaltza.Credit: Joseba Rios

And while everybody is speculating, Rios-Garaizar suggests a wonderful theory.

By 45,000 years ago, Neanderthals were clearly under stress. They vanished from Cantabria, possibly because of resource stress. This was a time of intense climatic variability, with very rapid, dramatic changes and, likely, howling storms. There may have been drastic environmental changes in northern Spain, leading to change in the fauna and, therefore, in those who hunt the fauna. Perhaps they needed to go farther to obtain the food they needed and, whether they died out or just left, Cantabria would remain free of Neanderthals until the next set came along armed with Châtelperronian technology.

Possibly these Neanderthals armed with Châtelperronian blades were so successful that they could be fruitful and multiply (hopefully beyond the nuclear family), and occupy new territories, Rios-Garaizar suggests. But not for long. They too disappeared, and fast.

Why? We do not know. Theories continue to compete but plausibly, at some point in Africa we the sapiens sapiens species crossed some sort of barrier, threshold, in brain evolution that rendered us intellectually superior to the Neanderthals. We gained abilities they may not have had, and after thousands upon thousands of years of “trying” (not that there was a declared aspiration), we made it past the Neanderthals and left Africa and spread madly throughout the world.

They, meanwhile, had been suffering from vagaries of climate and armed with Châtelperronian technology or not, we outcompeted them, and perhaps dealt better somehow with the environmental stressors, possibly due to better sociability. They grew more and more stressed; we may have coexisted cheek by jowl in some areas, especially in the Middle East, for thousands of years – but the upshot is that here we are today, while they are not.

And we may never know just how culturally advanced they were. We may never know whether they really could swim like fish. We may never be sure they really did have digging sticks, whether they had religion or just wanted to emulate big birds; whether they could cook soup, or whether it really was a custom, as has been postulated in one case of late Neanderthals in Iraq, that they buried their dead with flowers. The only thing for sure is that they're extinct.

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