Nearly 2 million years ago, a young ancient human died next to a spring near a lake in what is now Tanzania, East Africa. After archaeologists discovered his fossilized bones in 1960, they used them to define the A handy manthe oldest known member of our own genus.
Paleoanthropologists define the first examples of the genus Homo relying heavily on their larger brains and sometimes smaller teeth, compared to other earlier ancestors such as the australopithecines, the most famous of which is Lucy. There were at least three types of early humans: A handy man, Homo rudolfensis and the best documented species, The man stood up. At least one of them created sites now in the archaeological record, where they brought and shared food, and made and used some of the first stone tools.
These archaeological sites date back to between 2.6 and 1.8 million years ago. The artifacts within them suggest greater cognitive complexity in Homo earlier than documented among any non-human primate. For example, at Nyayanga, a site in Kenya, anthropologists recently discovered that early humans used tools that they carried over distances of up to 13 kilometers. This action indicates foresight and planning.
Traditionally, paleoanthropologists believed that the A handy manlike the first large-brained humans, was responsible for the first tool sites. The idea has been that the A handy man was the ancestor of The man stood up later and even larger-brained, whose descendants eventually led to us.
This narrative made sense when the oldest known remains of The man stood up They were less than 1.6 million years old. But given recent discoveries, this seems like a shaky foundation.
In 2015, my team discovered a 1.85 million-year-old hand bone in the Olduvai Gorge, the same place where the A handy man original. But unlike the hand of that A handy man juvenile, this fossil appeared to belong to a larger, more modern, and entirely terrestrial rather than tree-based human species: The man stood up.
Over the last decade, new findings have continued to push back the earliest dates of the The man stood up: about 2 million years ago in South Africa, Kenya and Ethiopia. Taken together, these findings reveal that H. erectus It is a little older than the known fossils of H. handy. We cannot simply assume that H. handy gave rise to H. erectus. On the other hand, the human family tree looks much thicker than we thought.
What do all these findings suggest? Just kind of Homo is our probable ancestor, and probably only one can be responsible for the complex behaviors revealed at the Olduvai Gorge sites. My colleagues and I found a way to test whether Homo habilis He was the best dog in the Olduvai Gorge, so to speak, depending on whether they were the hunters or the hunted.
Who hunted who?
In the Olduvai Gorge, there is overwhelming evidence that early humans consumed animals as large as a gazelle or even a zebra. Not only did they hunt, but they repeatedly brought these animals to the same place for communal consumption. This is the concept of a “central supply place,” much like a campsite or house today. Dating back to 1.85 million years, this is the oldest evidence of frequent meat eating, and that early humans regularly acted as predators rather than prey.
All animals occupy a position in a food web, from the highest ranks to the lowest. High-ranking predators, such as lions, are generally not prey to lower-ranking carnivores, such as hyenas.
You may be interested in: Museums around the world show solidarity with the Louvre: ‘We are neither bastions nor safes’
And Homo habilis was acquiring carcasses of large animals, either by hunting or scaring lions away from their own prey, it seems logical that these hominids could effectively cope with the risks of predation. That is, a hunter is generally not hunted.
In African savannahs, apex predators like lions do not usually die from attacks by other predators. Today’s humans also occupy a top predator niche: for example, Hadza hunter-gatherers in Tanzania not only hunt, but also defend lions from their prey and successfully defend themselves against attacks from other predators, such as leopards.
But if Homo habilis was not yet a top predator, so you would expect them to have occasionally fallen prey to carnivorous cats from the bottom of the food chain, such as leopards, which often prey on primates.
Most known human fossils at this stage of evolution have traces of carnivorous damage, including the two fossils of H. handy best preserved of the Olduvai Gorge. Was it caused after death, by a carnivorous scavenger? Or did a big cat at the top of the food chain kill these early humans?
My colleagues and I set out to address the question of which predators were setting their teeth on H. handy and presumably whether before or after ancient humans died.
The AI suggests that H. handy was not an apex predator
This is where artificial intelligence comes into play. Using computer vision, we trained AI on hundreds of microscopic images showing tooth marks left by the main carnivores in Africa today: lions, leopards, hyenas and crocodiles. The AI learned to recognize the subtle differences between the marks made by different predators and was able to classify the marks with great accuracy.
When we combined different AI approaches, they all pointed to the same result: the teeth marks on the bones of A handy man They coincided with those made by leopards. The size and shape of the marks on the fossils of those first two individuals of A handy man they align with what leopards leave behind today when they feed on prey.
Our discovery challenges the long-held view of A handy man as the first skilled tool maker, hunter and carnivore.
But maybe it shouldn’t be too surprising. The only complete skeleton of this species found in the Olduvai Gorge belonged to a very small individual, approximately 3 feet tall (less than 1 meter), with a body that still displayed characteristics suitable for climbing trees. That hardly matches the image of a hunter capable of taking down large animals or stealing lion carcasses.
If it wasn’t him A handy man the one who performed these feats, perhaps it was Homo erectusa species with a larger body and more modern anatomy. But that opens up other mysteries for future researchers: What was the A handy man at the Olduvai Gorge archaeological sites if he was not responsible for the hunting tools and signs we found there? Where exactly did it come from Homo erectus and how did it evolve?
My team and others will be returning to places like Olduvai Gorge to ask these questions in the years to come.
*Manuel Domínguez-Rodrigo is a professor of Anthropology at Rice University.
This article was originally published on The Conversation
Do you use Facebook more? Follow us to always be informed
