Fall of the Neanderthals
There may be no single reason for one of the planet’s most famous exits, Evana Ho reports.
On the way to the field site at the start of the Pyrenees mountains, there is sometimes the stench of pig.
“Depending on the wind, you get the smell from the pig farms,” says ANU archaeologist Dr Sofia Samper Carro.
Vultures circle above, on the lookout for their next meal. Those pig farms, along with other parts of the plains dedicated to growing fruit from citrus to stone fruits, are a relatively recent occurrence. At least in terms of the timescale Sofia is concerned with.
She's been returning for the past 10 years, since she began her first PhD. She and colleagues from the Universitat Autonoma de Barcelona toil in an area relatively unexplored, but proving to hold important pre-historical value. Since 2002, the team have been excavating and analysing remnants from Homo neanderthalensis (Neanderthal) and Homo sapiens occupation.
Estret de Trago, the oldest site, dates to around 130,000 years ago. Cova Gran, a rock shelter, has the longest sequence of human occupation of the five sites, spanning around 40,000 to 4,000 years ago. It's also the only site they've investigated in the south of the Pyrenees that was used by both Neanderthals and Homo sapiens.
“We're trying to understand what Neanderthals were doing: how they were living, what they were eating, the tools they were using,” Sofia says. “I wanted to see what was happening before Homo sapiens were there, and what happened when they arrived.”
Shedding light on this crucial transitional period could help solve a mystery that has plagued researchers for decades: what killed the Neanderthals? Sofia and her colleagues are edging their way to some answers.
“What we see is, Neanderthals were at these sites for around 100,000 years. Then suddenly, they disappeared from the record around 40,000 years. So we are examining their disappearance, but also looking at their last thousands of years of making use of these landscapes.”
The window that they have is into the tail end of the existence of the Neanderthals who lived across Eurasia for almost 400,000 years. Their extinction coincided with the arrival of Homo sapiens in Europe. This raises the question, was the extinction of the Neanderthals brought about by Homo sapiens? And if so, what form did this take: did our kind directly wipe them out through violence,
through diseases they introduced, or was it our technological superiority that made us more successful in competing for presumably shared resources? Or perhaps it was a force greater than both species: climate change.
The findings Sofia and her team have made over the years indicate that the Neanderthals' end came rather unexpectedly.
“There was no big crisis that predicted they were going to disappear,” she says.
“They were hunting big animals, doing as they had thousands of years before. The environment there didn’t seem to have changed dramatically. Then suddenly they were no more.”
The team didn’t find big differences from 70,000 years ago to 43,000 years ago – but also not big innovations in their diet or stone stools.
“However there may have been small variations that were significant and indicative of adaptation that we haven’t identified yet,” Sofia says.
“One of the problems with archaeology is how much is lost from the original material to what we find. There are some materials that don’t preserve well.”
Sofia has been in the process of analysing animal bones that are around 70,000 years old from a site, Abric Pizarro. What she has observed is that, in both Cova Gran and Abric Pizarro, Neanderthals were hunting animals and bringing the parts with more meat or those that required further processing to the site.
“What we are also seeing is that some of these sites may have been used as temporary stops,” Sofia says. “Overnight camp sites or brief stays in their movements through the territory searching for food and raw materials to make tools. This tells us about the Neanderthals’ capacities and their deep knowledge of their environment.”
South of the Pyrenees, Neanderthals hunted horses, red deer, and the auroch – a prehistoric bull that stood up to six feet tall and weighed around one tonne. The physique of the Neanderthals – stocky, shorter and with larger feet than the Homo sapiens – made them well suited to the sort of short distance, close-range hunting they did. They also had bigger brains than Homo sapiens, which required a higher caloric intake.
In general, the animals Neanderthals hunted everywhere they lived were medium to large in size. Another hypothesis for the demise of the Neanderthals is that climate change killed off many species of larger animals, and Neanderthals failed to adapt by hunting and eating smaller animals. But in sites around the world, and in Spain where Sofia and her team have been working, more findings suggest that Neanderthals were consuming smaller animals too.
“They were active and capable, probably able to hunt rabbits, birds, turtles and other small animals. That's one of the things I'm looking at, trying to assess if the lack of innovations we assumed is right or instead, if Neanderthals were changing their diet according to changes in climate and maybe, competition with other hominins around,” says Sofia.
She has over 300 rabbit bones in her office that she brought over from Spain. She's examining them for evidence of hunting, patterns of marks that show the rabbits died at the hands of humans.
“For a long time, it was thought only modern humans were able to hunt rabbits, birds, and other small animals. But it seems Neanderthals were also able to create traps or devices to hunt these.
She adds: “What we know so far, is that they were exploiting the resources they had in their area in a very proficient way.”
By and large though, there wasn't a significant overlap between the food sources of Neanderthals and Homo sapiens.
“We see a clear change in these sites from what we have with Neanderthals to when Homo sapiens appeared,” Sofia says. “There is a clear change in stone tools; Homo sapiens were hunting more goats rather than the bisons and horses Neanderthals pursued.”
Sofia's personal interpretation based on all the available evidence might disappoint those hoping for a clear and unambiguous reason for the demise of the Neanderthals. She believes it was a multitude of factors that felled the species.
“Climate change across time, maybe disease, demographic changes... I don't think it's possible to single out any one factor. However, it is exciting to research our close relatives to see how different or similar we are.”