They say great minds think alike. Now a paper in Nature suggests that very early humans, or possibly even hominins predating modern humans, may have invented advanced stone-tool manufacturing technology more than once, in different places around the world.
The thinking has been that the Levallois technique of knapping stones into tools was born in Africa and/or Europe, and spread to Asia. But the sophisticated method may have developed independently in each continent, postulates Prof. Ben Marwick of the University of Washington, writing with Bo Li and Hu Yue of the University of Wollongong, after discovering Levallois-type tools in China from a period way earlier than had been expected.
Pre-hominins were making stone tools over 3.3 million years ago, but their products and technique were crude. Simple hand axes were made by banging a suitable flint rock using another flint rock, until one of them acquired the desired shape.
Levallois (pronounced Le-val-wa) takes brains and finesse. This type of implement – “the Swiss Army knife of prehistoric tools,” Marwick calls them – required planning. The first stage involved gingerly banging at a flint core around its edges, carefully sculpting it into a specific shape. The second stage was to give the shaped rock one great, skillfully aimed whack that would knock off a flake, already roughly in the desired form and size.
Thusly, much sharper and finer tools could be made. “Featuring a distinctive faceted surface, created through a sequence of steps, Levallois flakes were versatile ‘blanks,’ used to spear, slice, scrape or dig,” the researchers explain.
Made in Israel
However, is it possible that the germ of the Levallois concept goes back as much as 800,000 years, before Homo sapiens was even a gleam in some Homo heidelbergensis' eye? Prof. Naama Goren-Inbar of Hebrew University believes she has identified "incipient" Levallois cores at Gesher Benot Yaakov in Israel – a prehistoric site that predates modern humans by hundreds of thousands of years.
Another Israeli researcher, Prof. Ran Barkai of Tel Aviv University, has identified Levallois tools (or incipients) going back half a million years in two other sites in Israel, Jaljulya and Revadim. Both sites have ample evidence of advanced stone-tool techniques.
Barkai cautions that dating these two sites is extremely challenging – both could be somewhat younger, “only” 300,000 years old. There is also evidence from Armenia, where a team headed by Daniel Adler found evidence of Levallois technology that dates between 400,000 to 200,000 years ago. In his paper in NCBI, Adler calls the technology “the most important conceptual shift in stone tool production strategies since the advent of bifacial technology more than one million years earlier.” Similar finds were made in India, Marwick adds.
As sites going back hundreds of thousands of years are extremely hard to date, we can roughly say that Levallois is apparently – at the very, very least – 300,000 years old. Which is when, according to the latest theories, modern man, Homo sapiens sapiens, was emerging from among his hominin brethren all over Africa.
Levallois technology had been thought to have reached Asia much later, around the Paleolithic period, 30,000 to 40,000 years ago, brought there by migrating modern humans. Evidently, not so: Marwick and the team report on dating Levallois tools found (decades ago) in Guanyindong Cave in Guizhou Province, China. Using newfangled technology that analyzed the sediments where the tools were found, they reached an age between 80,000 and 170,000 years.
Analysis of 2,200 artifacts found in Guanyindong Cave led to 45 Levallois-style stone cores and flakes, they elaborate.
Even the earlier date in the range, 80,000 years, is before the human-evolution models have modern humans migrating to China (though that could be wrong).
And if Goren-Inbar's diagnosis of the stone cores in Gesher Benot Yaakov is accurate, at least the germ of Levallois might even predate the split between Homo sapiens and Neanderthals.
"It seems plausible because we have a well documented case in Armenia," notes Marwick, who agrees that, theoretically, Homo erectus could have been the ancient inventor. "But we would need to see the artifacts combined with some hominin bones, fossils, before we can be confident. Until then, all we can do is speculate," he tells Haaretz.
To err is to be Neanderthal
The name “Levallois technique” received its name from the Parisian neighborhood where it was first unearthed, Levallois-Perret, in the 19th century.
If Levallois technology was being used over 300,000 years ago or before we existed at al), who exactly was using it?
At least in Morocco, it was apparently being used by some kind of Homo sapiens, since we see the tools and human bones together at Jebel Irhoud, Marwick tells Haaretz. “Later, they are also used by Neanderthals in Europe.”
One possibility, Barkai suggests, that humans evolved rather earlier than we have been thinking. (Neanderthals are “Homo neanderthalensis,” by the way; nobody thinks they were dull as bricks anymore, though their capabilities are still hotly debated.)
Barkai agrees that Levallois was associated with Neanderthals. But in contrast to Marwick, and based on the evidence in Israel, Barkai is confident that Homo erectus was capable of either Levallois itself, or the precursor to that technique. Erectus was probably the one who started stone tool making down that road, he thinks. And again, if the technology goes back over half a million years, it definitely wasn't invented by a human.
So, could Levallois have originated once, for the sake of argument, in Africa or the Levant, and “migrated” with early humans as they spread? Sure.
But the discovery of Levallois technology in so many places, from so many times, leads to thoughts that it originated independently in more than one spot, which is the point of the new paper. “The evidence is accumulating in support of that scenario,” says Marwick.
No human fossils have been found linking the Levallois tools to migrating human populations. But then, hardly any hominin fossils have been found in Asia, period.
Another question mark hovers over the Neanderthals. OK, there are dozens of question marks about Neanderthals, but one is whether they were ever in Africa. They definitely thronged the Levant, where modern Israel is now, and mated with Homo sapiens here too.
It’s hard to say things more categorically – partly because the dating of Levallois sites involves elephantine margins of error; partly because of the sheer scarcity of fossil remains from human evolution anywhere, let alone in Asia; and partly because, due to that paucity, we are still unclear who our direct ancestors were. Archaeologists are still arguing over whether we humans stem from Homo ergaster or Homo erectus, not to mention whether ergaster and erectus were actually the same species.
It is entirely possible that discoveries now being made in Asia will change our understanding of human evolution, Marwick says.
“East Asia is an exciting and challenging area to study human evolution. So much of the world’s current population live there, but we know so little about how they got there,” he says. “Compared to Africa and Europe, we have not had as much time or resources to find evidence in Asia. But we’re catching up, because the evidence is increasingly showing that this region is an important and unique part of the story of how we became human.”