Think about a creature practically twice the dimensions of a contemporary African elephant (which might weigh as much as 6,000kg [13,000 lbs]). This was Elephas (Paleoxodon) recki, a prehistoric titan that roamed the panorama of what’s now Tanzania practically two million years in the past. Now, think about a bunch of our ancestors standing over its carcass, then butchering it and consuming it.
For many years, archaeologists have debated when the hominin ancestors of people first began consuming megafauna — animals weighing greater than 1,000kg [2,200 pounds].
This was at Olduvai Gorge in Tanzania, a web site well-known for holding a number of the oldest and finest preserved stays of our human ancestors. Relationship again to 1.80 million years in the past, this discovery on the web site generally known as EAK reveals that our ancestors had been partaking with megafauna considerably sooner than beforehand thought (about 1.5 million years in the past was the earlier estimate at Olduvai), and in a extra subtle manner.
This discovering means that hominins (almost certainly, Homo erectus) might have been residing in giant social teams at this era, most likely as a result of their brains had been creating and demanding higher-calorie diets wealthy in fatty acids.
“Smoking weapons”
A part of the rationale our historical food regimen has been debated is that it’s not straightforward to seek out proof of how a lot animal meals early people had been consuming and the way they had been buying it.
In conventional archaeology, the “smoking gun” for butchery (slicing up carcasses) is a lower mark left on a bone by a stone device. Nonetheless, when coping with huge animals like elephants, these marks are troublesome to seek out. An elephant’s pores and skin is a number of centimeters thick, and its muscle mass is so huge {that a} butcher’s device would possibly by no means contact the bone. Moreover, tens of millions of years of burial can climate the bone floor, erasing any refined traces. And if a bone is deposited in an abrasive sediment, trampling by different animals might generate marks on bones that appear like lower marks.
On the EAK web site, we discovered the partial skeleton of a single Elephas recki particular person in the identical place as Oldowan stone instruments. However to show that this wasn’t only a pure dying or the work of scavengers, we could not depend on bone marks. As a substitute, we turned to a brand new type of detective work: spatial taphonomy. That is the examine of how stone artefacts and bones happen spatially on the identical web site. We additionally turned to extra direct proof: bones from these fossilized elephants that had been splintered whereas they had been contemporary (“inexperienced breaks”).
The geometry of a carcass
To unravel this 1.8-million-year-old thriller, we analyzed the best way the bones had been scattered throughout the location. Each agent that interacts with a carcass — whether or not it’s a delight of lions, a bunch of hyenas, or a band of people — leaves a novel “spatial fingerprint”. Lions and hyenas have a tendency to tug bones away, scattering them in predictable patterns based mostly on their weight and the quantity of connected meat. Pure deaths, like an elephant dying in a swamp, end in a special, extra localised skeletal “collapse”.
By utilizing superior spatial statistics, and later evaluating the EAK web site to a number of trendy elephant carcasses that we studied in Botswana (not but printed), we discovered that the spatial configuration at EAK was distinctive. The clustering of the bones and the density of the stone instruments amongst them didn’t match the “random” or “scavenger-driven” fashions. As a substitute, it mirrored a centered, high-intensity processing occasion. The spatial signature was a match for hominin butchery, which has additionally been documented at Olduvai websites which might be half 1,000,000 years youthful.
This was confirmed by the presence of green-broken lengthy bones not simply at EAK, however in a number of places within the panorama the place different elephant and hippopotamus carcasses had been butchered. Right now, solely people can break elephant lengthy bone shafts; not even noticed hyenas, which have very highly effective jaws, can do it.
Glimpses of this habits could be detected at different websites too. For instance, a cut-marked bone fragment of a big animal (most likely a hippopotamus) was documented at El-Kherba (Algeria) dated to 1.78 million years in the past.
This intensive and repeated discovery of a number of elephant and hippopotamus carcasses butchered at completely different panorama places signifies that people had been butchering the stays of enormous animals, whether or not hunted or scavenged.
Why does an elephant meal matter?
This discovery is not nearly a prehistoric menu; it is concerning the evolution of the human mind and social construction. There’s a long-standing principle in paleoanthropology referred to as the “costly tissue speculation“. It means that as our ancestors’ brains grew bigger, they required a large enhance in high-quality energy, particularly fats and protein. Massive mammals like elephants are primarily big “packages” of those energy. Processing even a single elephant supplies a caloric windfall that might maintain a bunch for weeks.
Butchering an elephant is a monumental process, nevertheless. It requires sharp stone instruments and, most significantly, social cooperation. Our ancestors needed to work collectively to defend the carcass from predators like saber-toothed cats and big hyenas, whereas others labored to extract the meat and marrow.
This means that even 1.8 million years in the past, our ancestors already possessed a stage of social group and environmental consciousness that was actually “human”.
The invention additionally has one other dimension. People at the moment, like trendy carnivores, consumed animals whose dimension was associated to their very own group dimension. Small prides of lions eat wildebeests; bigger prides eat buffalo and in some locations even juvenile elephants. The proof that these early people had been exploiting giant animals is available in parallel with proof that they had been residing in a lot bigger websites than earlier than, most likely reflecting larger group sizes.
Why early people began residing in giant teams at the moment stays to be defined, however this means that they definitely wanted extra meals.
A shift within the ecosystem
The EAK web site additionally tells us concerning the setting. By analyzing the tiny fossils of crops and microscopic animals present in the identical soil layers, we reconstructed a panorama that was transitioning from a lush, wooded lake margin to a extra open, grassy savanna. Our ancestors had been already consuming smaller recreation. There’s proof that two million years in the past, they had been searching small and medium-sized animals (like gazelles and waterbucks). A bit of earlier, they started utilizing know-how (stone instruments) to bypass their organic limitations.
The proof from Olduvai Gorge exhibits that our ancestors had been remarkably adaptable, able to thriving in altering climates by creating new behaviours.
As we have a look at the spatial format of those historical stays, we aren’t simply wanting on the bones of an extinct elephant. We’re wanting on the traces of a pivotal second in our personal historical past — when a small group of hominins checked out a large and noticed not only a risk, however a key to their survival.
This edited article is republished from The Dialog underneath a Artistic Commons license. Learn the unique article.
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