Study of ancient footprints first ever to show that early ancestors coexisted in shared space
In the arid landscapes of northern Kenya, a remarkable discovery is reshaping our understanding of human evolution. Scientists have uncovered 1.5-million-year-old footprints that provide the first direct evidence that two different early human species likely encountered one another, potentially sharing the same territories and resources.
The exciting research, published in Science, centers on a series of fossilized footprints found at a site called ET-2022-103-FE22 (abbreviated as FE22) near Lake Turkana. What makes these tracks extraordinary isn’t just their age, but what they reveal about our ancient relatives’ coexistence and movement patterns.
The site preserves a continuous trackway made by one individual and three isolated footprints from different individuals, all pressed into what was once wet, muddy ground near an ancient lakeshore. Alongside the human footprints are tracks from various animals, including massive bird prints likely left by ancient marabou storks, as well as tracks from bovids (antelope-like animals) and equids (horse family members).
But the real story lies in the distinct differences between the footprints. The research team, led by Kevin Hatala from Chatham University, found two clearly different walking patterns preserved in these ancient tracks. One set of prints shows characteristics very similar to modern human footprints, while the other set reveals a notably different way of walking.
“Fossil footprints are exciting because they provide vivid snapshots that bring our fossil relatives to life,” says Kevin Hatala, the study’s first author, and an associate professor of biology at Chatham University, in a statement. “With these kinds of data, we can see how living individuals, millions of years ago, were moving around their environments and potentially interacting with each other, or even with other animals. That’s something that we can’t really get from bones or stone tools.”
Through careful analysis using advanced 3D imaging technologies, the research team identified two distinct patterns of movement in the human footprints. The continuous trackway shows evidence of someone walking at a brisk pace of 1.81 meters per second, but with notably different foot mechanics than modern humans. These tracks are flatter and show signs of a more mobile big toe. In contrast, the isolated footprints more closely match the arch patterns and toe alignment seen in modern human feet.
“In biological anthropology, we’re always interested in finding new ways to extract behavior from the fossil record, and this is a great example,” says Rebecca Ferrell, a program director at the National Science Foundation. “The team used cutting-edge 3D imaging technologies to create an entirely new way to look at footprints, which helps us understand human evolution and the roles of cooperation and competition in shaping our evolutionary journey.”
This distinction is crucial because it suggests these tracks were made by two different early human species: Homo erectus and Paranthropus boisei. H. erectus is often considered our direct ancestor and is thought to have walked very similarly to modern humans. P. boisei, meanwhile, was a more robust species with a distinctly different body build and, as these footprints suggest, a different way of walking.
The lake margin environment where these tracks were preserved offers a rare snapshot of ancient life, frozen in time. The footprints were made within hours or days of each other, suggesting these two species weren’t just living in the same general region, but were actively using the same spaces at nearly the same time.
What’s particularly intriguing is that this pattern of coexistence shows up repeatedly in the fossil record of this region between 1.4 and 1.6 million years ago. Multiple sites preserve evidence of these two distinct walking styles, indicating this wasn’t a one-time encounter but rather a sustained pattern of shared habitat use.
“This proves beyond any question that not only one, but two different hominins were walking on the same surface, literally within hours of each other,” says co-author Craig Feibel, a professor in the Department of Earth and Planetary Sciences and Department of Anthropology in the Rutgers School of Arts and Sciences. “The idea that they lived contemporaneously may not be a surprise. But this is the first time demonstrating it. I think that’s really huge.”
Interestingly, Feibel notes that Homo erectus lived for 1 million years more than. Paranthropus boisei. As to why the latter went extinct much sooner remains a mystery.
This discovery challenges previous limitations in studying ancient human coexistence. While fossilized bones can tell us different species lived in the same general area over thousands of years, footprints provide a much more intimate window into their daily lives and interactions. These tracks show that different human species weren’t just inhabiting the same general region – they were walking the same paths, perhaps even encountering one another face to face.
The findings suggest that despite their differences, these two species found ways to share resources without excessive competition. The lake margin environments where they left their tracks would have provided various food sources and other resources that could have supported both species’ needs. This peaceful coexistence might help explain how multiple human species managed to survive alongside each other for hundreds of thousands of years.
The implications of this research extend beyond just understanding ancient human behavior. It provides insights into how species adapt to share environments and resources, a topic that remains relevant today as we grapple with questions of human impact on other species and their habitats.
While we may never know if these different species exchanged greetings or avoided each other’s gaze, their footprints tell us something profound: Long before we built cities or drew maps, different kinds of humans were already figuring out how to share their world. Perhaps that’s the most human trait of all.
Source : https://studyfinds.org/ancient-footprints-two-human-species/