(CN) — New research on fossil footprint evidence suggests that humans were present in North America earlier than previously believed.
Researchers led by Matthew Bennett, a geographer at England’s Bournemouth University, studied a series of human fossil footprints found in an ancient lakebed in White Sands National Park, located in New Mexico. Their findings will be released in an article to be published Friday in the peer-reviewed academic journal Science. An advance copy provided to Courthouse News detailed the evidence that humans were in North America during the last ice age.
The footprints are roughly 21,000 to 23,000 years old and show that human arrival in southern North America predates the time before glacial advances of the last ice age shut off travel between Asia and North America via the Bering land bridge, which connected Alaska and Siberia.
The “Last Glacial Maximum,” or LGM, refers to a time during the last ice age when ice sheets and glaciers reached their peak extent across the world. These ice sheets and glaciers radically affected the world’s landscapes and migration patterns.
“The evidence presented here confirms that humans were present in North America before the glacial advances of the LGM closed the ice-free corridor and the Pacific coastal route and prevented human migration from Asia,” the authors wrote in the paper.
The ice-free corridor and a known Pacific coastal route would have been difficult for early humans to navigate during the last LGM.
In the late 20th century, it was believed that humans had first arrived to the Americas as recently as 13,000 years ago. Bennett’s findings add to a mounting pile of evidence that the Americas were peopled significantly longer ago than these early estimates.
Researchers have spent many decades trying to decipher the migration patterns of early humans to the Americas to study their impact on the landscape.
This new timeline of human migration to North America shows that humans would have overlapped with large ancient animals referred to as “megafuana” for at least two millennia.
Studying this time of coexistence between humans and these animals is important to researchers because it would provide valuable insights into what happened to these animals, why they went extinct and how humans of the time survived.
“The overlap of humans and megafauna for at least two millennia during this time suggests that if people were hunting megafauna the practices were sustainable, at least initially,” the paper states. “This also raises the possibility of a human role in poorly understood megafauna extinctions previously thought to predate their arrival and makes ‘early’ sites in the Americas appear more plausible.”
The researchers believe that the tracks they studied belonged to those of teenagers and children, as adult footprints are less commonly found. The paper suggests that one hypothesis for this is because the division of labor of early humans may have delegated “fetching and carrying” tasks to the young.
While the findings of the paper provide concrete evidence that humans existed in New Mexico during this time, it does not indicate when humans arrived.
“However, exactly when people first arrived in the Western Hemisphere and when continuous occupation was established are still both uncertain and contested. What we present here is evidence of a firm time and location when humans were present in North America,” the scientists wrote.
Lead author Bennett was assisted by individuals representing the National Park Service, White Sands National Park, the University of Arizona, Cornell University, the U.S. Geological Survey, Denver Federal Center and his colleagues at Bournemouth University.