Scientists have found fossil footprints of humans in New Mexico, which they believe are the oldest footprints of humans, dating back about 23,000 years, suggesting that humans may have reached North America earlier.
It is widely believed that at the end of the Ice Age, about 13,000 to 16,000 years ago, people arrived in North America from Asia via the Bering Land Bridge, which once connected the two continents. But recent controversial findings suggest that humans may have been in North America earlier.
The scientists detailed their findings in a new study in the Sept. 24 issue of the journal Science.
They found fossil footprints of humans in New Mexico, a discovery the researchers believe is conclusive evidence of early migration to the New World.
Scientists point out that while the newly discovered footprints may not be the oldest evidence of humans reaching the Americas, they may be the first definitive evidence that humans lived there during the last ice age.
The first humans in the Americas
Tens of thousands of years ago, the Americas were not inhabited by humans. This changed during the last ice age
At the time, much of North America was covered in thick ice, which made it difficult for humans to live here. But sometime in this era, some adventurous people began to enter this new world
According to media reports, as early as 2009, David Bustos, the resource project manager of the White Sands National Park in the United States, found the first footprint in the ancient wetland.
Over the years, he and other researchers have found more footprints in the park. Scientists at the U.S. Geological Survey recently analyzed seeds stuck in footprints to determine their approximate age, around 22,800 to 21,130 years ago.
The arrival of the first people in the Americas was a crucial step in human expansion on Earth, but the exact timing of this milestone remains hotly debated.
There is still controversy over when these first Native Americans arrived here and where they came from. But we are now getting closer and closer to the original factual process and the determination of their true identity.
Based on stone tools dating back about 13,000 years, archaeologists have long believed that the Clovis people from prehistoric cultures were the first to migrate to the Americas.
Clovis culture
The Clovis culture, also known as the Lano culture, is a prehistoric Paleo-Indian culture on the North American continent. "Clovis culture" is named after the "Clovis Stone Spear".
The "Clovis Stone Spear" is a stone tool used by humans in prehistoric America. It was first unearthed in the American town of Clovis. It is believed to be one of the earliest evidences of human activity found on the North American continent to date.
According to radiocarbon dating, its remains date back to the last ice age 11,500 years ago, which is roughly equivalent to 13,500 calendar years. The most special thing is that they have special tools to hunt large mammals.
The Clovis culture lasted for about 200-800 years. In the cold climate of the Neo-Nymph period, they were outlawed by many local cultures.
The researchers claim that the comet impact that occurred 12,900 years ago may have wiped out the Clovis people in North America. Researchers have recently uncovered a wealth of evidence about Clovis's previous artefacts.
Scientists revealed last year that stone tools found in the Chikiwhit Cave in central Mexico are at least 26,500 years old;
Computer models found that the cave is located inland in the Americas, so far from the Old World where human migration arrived, suggesting that humans may have first entered the New World as early as 33,000 years ago.
Nevertheless, the earliest archaeological evidence of human settlement in the Americas remains highly controversial. Even the scientists who excavated the Chikiwhit Cave say others may argue that the stone tools found there did not come from humans, but were merely "geological remains," or ordinary rocks that appeared to be man-made.
The discovery
60 footprints embedded in an ancient lakebed in White Sand National Park in south-central New Mexico are strong evidence that humans occupied the New World some 21,000 to 23,000 years ago.
The prints were made during the peak of the Last Ice Age, about 19,000 to 26,500 years ago, when the Ice Age peaked and glaciers covered about a third of the earth's land.
Matthew Bennett, a geologist at the University of Bournemouth in the United Kingdom, told LiveScience: "The White Sand Footprints provide clear evidence of early occupation, with several early proposed sites, such as Chikiwhit, all controversial. Footprints are the first clear data point in this debate. ”
Bennett said the prints were made in what was once the edge of a wetland, an area that was "slightly wetter than it is today, but still very dry."
Other footprints have been found in the area, including those of mammoths, ground sloths, canines, cats, cows and camels.
By using carbon dating for seeds found in sediments within the imprint, the researchers calculated the age of the imprint.
"It's not the oldest site, but it's a site with clear evidence, and that's how important it is," Bennett said.
Similar to the fossilized footprints of humans previously analyzed by the researchers in Namibia, the newly discovered footprints were left by people with flat feet that are more common than those found in modern humans; they are similar to those common to people with habitual barefoots.
conclusion
Many of these newly discovered footprints appear to have come from teenagers and children; larger adult footprints are not so common.
One possible explanation for this, the researchers believe, is the division of labor, in which adults participate in skilled tasks while teenagers are assigned to pick up and carry tasks, while children are labeled along with teenagers.
These findings suggest that humans occupied southwestern North America for at least 2,000 years during the last glacial period.
"Besides, we believe they've been there for a lot longer than we can say at the moment for two thousand years," Bennett said.
The prints were made before the glacier advanced, when it closed the ice-free corridor that once connected the continents of Asia and North America, as well as a Pacific coastal route that one might have passed from the Old World — thought to Africa, Europe and Asia — to the New World.
These new findings suggest that people had already entered the Americas thousands of years before the last glacial period prevented migration by either method, Bennett said. "People have plenty of time to choose whatever route they choose to migrate south,"
Researchers say the discovery that humans may have occupied the Americas at such an early time suggests that if there were ancient hunters hunting mammoths and other megafauna in the New World, they did so in a sustainable way, at least initially.
If they hadn't, these oversized creatures would probably have gone extinct sooner. On the other hand, the researchers add, it also increases the possibility that humans may eventually play a role in the extinction of megafauna previously thought to precede humans' arrival in the Americas.
Such footprints can also help humans today feel some connection to the past, Bennett told LiveScience: "I think footprints are the most amazing way to connect with the past, and everyone has left footprints on the beach that can connect to the past." ”
The pandemic stopped working on the site after January 2020. The researchers hope to restart their study in January 2022.
Bennett says "the work allows us to learn more about the people who leave the track.".