Were early humans hunters — or hunted?
For decades, researchers believed that Homo habilis — the earliest known species in our genus — marked the moment humans rose from prey to predators. They were thought to be the first stone tool users and among the earliest meat eaters and hunters based on evidence from early archaeological sites.
Source: Manuel Domínguez-Rodrigo
But fossils of another early human species — African Homo erectus — show they lived alongside H. habilis about 2 million years ago. That raised a new mystery: Which of these two species was actually making tools and eating the meat of hunted animals? Most anthropologists long suspected H. habilis was responsible, which would have placed them in a dominant predatory role.
New findings from a team led by Rice University anthropologist Manuel Domínguez-Rodrigo, in partnership between Rice and the Archaeological and Paleontological Museum of Madrid through the Institute of Evolution in Africa (IDEA), which he co-directs with Enrique Baquedano, challenge that view, revealing that these early humans were still preyed upon by carnivores, likely leopards. The work is published in the Annals of the New York Academy of Sciences.
“We discovered that these very early humans were eaten by other carnivores instead of mastering the landscape at that time,” Domínguez-Rodrigo said.
The breakthrough was made possible by applying artificial intelligence (AI) to fossil analysis, giving researchers insights they could not have reached with traditional methods alone. Domínguez-Rodrigo is among the first anthropologists to use AI for taxon-specific analysis of bone surface damage — training computer vision models to recognize the microscopic tooth mark patterns left by different predators.
“Human experts have been good at finding modifications on prehistoric bones,” he said. “But there were too many carnivores at that time. AI has opened new doors of understanding.”
His team trained deep learning models to distinguish bone damage left by leopards, lions, hyenas, crocodiles and wolves. When the models analyzed marks on H. habilis fossils from Olduvai Gorge in Tanzania, they consistently identified leopard bite marks with high confidence.
“AI is a game changer,” Domínguez-Rodrigo said. “It’s pushing methods that have been stable for 40 years beyond what we imagined. For the first time, we can pinpoint not just that these humans were eaten but by whom.”
Source: Manuel Domínguez-Rodrigo
The finding challenges a long-standing idea about when and what type of humans began to dominate their environment, showing that even as their brains were beginning to grow, they were still vulnerable.
“The beginning of the human brain doesn’t mean we mastered everything immediately,” Domínguez-Rodrigo said. “This is a more complex story. These early humans, these Homo habilis, were not the ones responsible for that transformation.”
He said it’s a reminder that human evolution wasn’t a single leap from prey to predator but a long, gradual climb and that H. habilis may not have been the turning point researchers once believed.
Domínguez-Rodrigo added that the methods developed for this study could unlock discoveries across anthropology, allowing researchers to analyze other early human fossils in new ways. The work is part of a growing collaboration between Rice and IDEA, where his team is based.
Photo by Scotto Solomon, Rice University
“This is a pioneer center in the use of artificial intelligence to the past,” he said. “It’s one of the first places using AI for paleontological and anthropological research.”
Domínguez-Rodrigo said he hopes this discovery is just the beginning. By applying AI to other fossils, he believes researchers can map when humans truly rose from prey to predator and uncover new chapters in our evolutionary story that have long been hidden.
“It’s extremely stimulating to be the first one to see something for the first time. When you uncover sites that have been hidden from the human eye for more than 2 million years, you’re contributing to how we reconstruct who we are. It’s a privilege and very encouraging.”
The study was co-authored by Marina Vegara Riquelme and Enrique Baquedano, and was supported by the Spanish Ministry of Science and Innovation, the Spanish Ministry of Universities and the Spanish Ministry of Culture.