The mammoth bones and “ghost” footprints of ancient people are the latest evidence in a scientific debate about when the first humans arrived in the Americas.
Fossilized bones, in particular, may suggest that people lived in North America thousands of years before the generally accepted date of the first Native Americans arrival, around 10,000 BCE.
Researchers say radiocarbon dates of chemicals in mammoth bones from a mother and her calf indicate that the animal lived in New Mexico about 37,000 years ago. The researchers said the pattern of fractures on the bones suggests they were crushed by humans, who may have been there at the same time. But the findings are disputed by some other scientists, who say the fractures could have occurred naturally.
Meanwhile, the latest “ghost” footprints were found a few weeks ago At an Air Force missile range in a desert in Utah. Scientists think they are about 12,000 years old, but this is only the second time such footprints have been found, and they support last year’s finding. Ghost Footprints in New Mexico It is believed to be at least 21,000 years old – although this finding is also disputed.
On high cliffs above a tributary of the Rio Grande called the Hartley Site in northern New Mexico, mammoth bones are believed to be the most conclusive evidence ever that humans arrived in the Americas by “land walking” 50,000 years ago. bridge” between what is now Siberia and Alaska.
The researchers say they are confident in their dating and interpretation that the fractures on them were caused by repeated impacts with sharp objects during their intentional butchering. They also say that there is evidence that fire was selectively used to cook many bones.
“I think this is a rock-solid radiocarbon date,” said paleontologist Timothy Rowe, a professor at the Jackson School of Geosciences at the University of Texas at Austin. “The skeptics will put everything under the microscope, but I think we checked every box.”
Rowe is the lead author of A study of giant bones published last month In the journal Frontiers in Ecology and Evolution.
Bone fractures and small flakes due to the butchering process are also typical and seen at butcher sites of similar age in Europe and Asia: “If this site were in northern Siberia, no one would have snapped,” he said.
The idea that mammoths were bitten by early humans is supported by other recent discoveries, including human footprints in White Sands National Park in New Mexico and what is called Stone tools made 33,000 years ago In a cave in northern Mexico.
But the idea, and the evidence, is disputed by other scientists. The dating of the White Sands footprints has been questioned, and some scientists think the objects in Mexico are not tools, but naturally sharp rocks.
And they dispute that fractures on mammoth bones could only have been done by humans; Instead, they can be caused by landslides or some other natural phenomenon.
“The patterns of fractures on those mammoth bones at that site could certainly be caused by humans,” said anthropologist Andre Kostopoulos, a professor at the University of Alberta in Edmonton. detailed online exam Latest research. “But they are not necessarily diagnosing human presence.”
“We don’t have clear evidence yet, because there are other possible explanations that need to be ruled out first, and they haven’t been done,” he said.
The lack of specialized stone tools at the Hartley site is also a problem. Researchers say that those who killed the mammoths may not have used sophisticated stone tools, but only primitive tools different from natural bones or rocks.
But other scientists say there is no evidence for this, and primitive humans of this time can be expected to have even better tools.
Archaeologist Ben Potter, a professor at the University of Alaska Fairbanks, said there is evidence from Africa, Europe and the Far East that Homo sapiens used complex stone tools around 47,000 years ago, and so their absence at the Hartley site is significant.
He said in an email that he disagrees with the latest research on mammoth bones and the idea that it shows people arrived in the Americas much earlier. “Anything is possible. However, we must have evidence to support the claim.” “I don’t think they have enough evidence yet, and certainly don’t on this site.”
However, some other scientists are more convinced, and suggest that others may be reluctant to face the possibility that some humans arrived in the Americas 50,000 years ago.
“The research looks very thorough,” said Spencer Lucas, curator of paleontology at the New Mexico Museum of Natural History and Science. “At what point will the archaeological community wake up and smell the coffee? There’s a lot of evidence,” he said.
“I’m not saying it’s the final piece of evidence… but you have White Sands footprints, and [Mexico] site – all kinds of evidence is accumulating pointing to human occupation of the New World 20,000 years ago, and I don’t understand why this idea is still worth debate.”
Improvement (August 4, 2022, 6:34 p.m. ET): A previous version of this article misquoted Ben Potter’s employment at the University of Alaska Fairbanks. He is currently a professor there, not before.