When did humans arrive in America? Scientists discovered that it was ten thousand years older than they had imagined

Humans occupied North America thousands of years earlier than previously thought, according to a study that confirmed the ancientness of fossilized footprints in White Sands National Park, in New Mexico, USA, using two different dating techniques.

The footprints were originally left between 21,000 and 23,000 years ago, according to radiocarbon dating and stimulated optical luminescence techniques, the researchers reported. This is approximately ten thousand years older than previously imagined.

The new work is published in the scientific journal SciencesIt reveals that Homo sapiens actually walked across North America during the last Ice Age, a period inhospitable to humans. At this time, much of the continent was covered in thick layers of ice.

A 2021 study published by the same researchers had already dated the footprints to between 21,000 and 23,000 years ago, based on plant seeds found in the same sediments in which the fossilized footprints were found. At the time, many scientists questioned the dating method.

Homo sapiens appeared on the African continent about 300 thousand years ago, and from there it spread throughout the world. Experts believe that humans arrived on the American continent on foot, at a time when Siberia and Alaska were connected by land.

“Every dating technique has strengths and weaknesses, but when three different techniques converge for the same time period, we can say the result is exceptionally strong,” geologist Jeff Bigatti of the Geology Center said in an interview with Reuters. US Government Geological, Geophysical and Geochemical Sciences (CCGGG) is a co-author of the work.

“Our original results were controversial and we knew we needed an independent evaluation to gain the trust of the community. This work was a supportive exercise,” said geologist Kathleen Springer, who also works at CCGG.