2023-10-24 04:00:08
The discovery of new fossil footprints is revolutionizing our knowledge of the human presence in America. Contrary to what was believed, humans would have set foot on this ground much earlier than imagined.
The prints come from a group of people of different ages.
Credit: National Park Service
For a long time, the scientific community thought that humans had reached the heart of America and the North. , opposite to the south.) regarding 14,000 years ago. This passage would have been made possible by the melting of the ice at the end of the last ice age. But a recent study published in the journal Science (Science (Latin scientia, “knowledge”) is, according to the dictionary…) turns these theories on their head.
20th century experts spoke of an ice-free corridor between two immense ice caps to explain human migration. But recent discoveries show human traces dating back 23,000 years in New Mexico, calling this vision into question.
If humans were already present in America during the last ice age, this suggests either routes through the ice or a much older presence.
Date the pollen
Fossilized pollen turned out to be a scientific tool of choice. Radiocarbon analyzes were carried out on seeds found in the sediments where the prints were discovered. This method makes it possible to date organisms that died within the last 50,000 years.
Researchers have cast doubt on these dates, citing a possible “hard water effect”. This effect might distort the data by artificially aging the carbon-14 contained in the pollen. But further testing confirmed the age of the prints.
Kathleen Springer and Jeff Pigati of the United States Geological Survey used a medical technique, flow cytometry, to count and isolate the grains. of pollen. After extensive laboratory work, the results validated the initial chronology and ruled out the effect of hard water.
This new study adds another stone to the building of our understanding of the human presence in America. It opens the way to new research that might redefine our vision of American prehistory.
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