Almost two million years ago, a young prehistoric man died at a spring near a lake in what’s now Tanzania in eastern Africa. After archaeologists discovered his fossilized bones in 1960, they put them to make use of define – the earliest known member of our own genus.
Universal History Archive/Universal Images Group via Getty Images
Paleoanthropologists define the primary examples of the genus based totally on their larger brains – and sometimes smaller teeth – in comparison with other, earlier ancestors similar to the australopithecines – probably the most famous of which is Lucy. There were not less than three species of early humans: , and the very best documented species, . At least one among them created archaeological sites today where they brought and shared food and made and used among the earliest stone tools.
These archaeological sites date back to 2.6 to 1.8 million years ago. The artifacts contained therein suggest greater cognitive complexity than has been documented in any non-human primate. For example, anthropologists recently found that early humans used it at Nyayanga, a site in Kenya Tools that they transported over long distances of as much as 8 miles (13 kilometers). This motion indicates foresight and planning.
Traditionally, paleoanthropologists believed that he was the primary large-brained human to be answerable for the earliest tool sites. The idea was that it was an ancestor of the later and even larger brain, whose descendants eventually led to us.
This narrative made sense when the oldest known stays were lower than 1.6 million years old. But given recent discoveries, this appears to be a shaky foundation.
Scott Solomon (Rice University)
In 2015, my team discovered one 1.85 million 12 months old hand bone in Olduvai Gorge, the identical place where the unique was found. But unlike this juvenile's hand, this fossil looked prefer it belonged to a bigger, more modern, entirely land-based, non-arboreal human species: .
Over the last decade, recent discoveries have pushed back the earliest dates for: about 2 million years ago in South Africa, Kenya And Ethiopia. Taken together, these discoveries indicate that it’s barely older than the known fossils. We can't just assume that's what happened. Instead, the human family tree looks so much bushier than we thought.
What do all these findings suggest? Only one species is our likely ancestor, and possibly just one could be answerable for the complex behaviors revealed on the Olduvai Gorge sites. My colleagues and I discovered a method to test whether it was the front runner, so to talk, in Olduvai Gorge, depending on whether or not they were hunters or hunted.
Who was hunting whom?
And Olduvai Gorgethere’s overwhelming evidence of this People consumed animals as big as a gazelle or perhaps a zebra. Not only did they hunt?but they all the time brought these animals back to the identical place for communal consumption. This is the concept of a “central supply location,” much like a campsite or home today. This is the oldest evidence of frequent meat consumption – dating back to 1.85 million years ago Early humans frequently acted as predators as a substitute of prey.
All animals occupy a position within the food web, from the highest to the underside. Top-class predatorsAnimals like lions will not be typically hunted by lower-ranking carnivores like hyenas.
If the goal was to accumulate large animal carcasses, whether through hunting or by scaring away lions from their very own prey, it seems logical that these hominids could effectively manage the chance of predation. That is, a hunter isn’t normally hunted.
African savannahs are home to top predators similar to lions normally don’t die from other predator attacks. Humans also occupy a top predator area of interest today: For example Hadza hunter-gatherers in Tanzania Not only do they hunt game, but in addition they fend off lions and successfully defend themselves against attacks from other predators similar to leopards.
However, in the event that they weren’t already a top predator, one would assume that they were occasionally prey of carnivorous cats lower on the food chain – similar to leopards – which regularly prey on primates.
Most known human fossils at this stage of evolution show signs of carnivore damage, including the 2 best-preserved fossils from Olduvai Gorge. Was it caused after death by a scavenging carnivore? Or did an enormous cat at the highest of the food chain kill these early humans?
My colleagues and I set out to research which predators got their teeth and, presumably, whether this happened before or after ancient humans died.
The AI suggests it wasn't an apex predator
This is where artificial intelligence comes into play Computer VisionWe trained the AI on a whole lot of microscopic images showing dental impressions left by an important carnivores in Africa: lions, leopards, hyenas and crocodiles. The AI learned and was capable of recognize the subtle differences between different predators' markings Classify the grades with high accuracy.
Domínguez-Rodrigo, M., et al. Sci Rep 14, 6881 (2024)
When we combined different AI approaches, all of them showed the identical result: the tooth marks on the bones corresponded to those of leopards. The size and shape of the tracks on the fossils of those two early individuals are consistent with what leopards leave today after they eat prey.
Our discovery challenges the long-held view of being the primary expert toolmaker, hunter and meat eater.
But perhaps it shouldn't be too surprising. The only complete skeleton of this species present in Olduvai Gorge belonged to a really small individual – only about 3 feet tall (lower than 1 meter) – with a body that also had features suitable for climbing trees. That hardly matches the image of a hunter who can kill large animals or steal lion carcasses.
If it didn't accomplish these feats, perhaps it was a species with a bigger body and more modern anatomy. But this opens up further mysteries for future researchers: What happened on the Olduvai Gorge archaeological sites if it wasn't answerable for the tools and hunting tracks we discover there? Where exactly did it come from and the way did it develop?
My team and others will return to places like Olduvai Gorge in the approaching years to ask these questions.
