For many years, it had been supposed that humans first entered the Americas around 16,000 years ago by crossing a land bridge that formed over the Bering Strait and then migrating down the Pacific Coast. This explanation was seen as logical due to evidence in archaeology and the significant amount of ice that prevailed before this timeframe. However, two years ago, a paper was released that adjusted this timeline using radiocarbon dating on ancient footprints from White Sands National Park in New Mexico. This new timeline suggests that these humans may have navigated the still-glacial Pacific Coast by boat.
Recently, further scientific testing has provided even more evidence that their daring, questionable assertions are accurate. The tests state that the footprints are approximately 23,000 and 21,000 years old, thus raising the debate surrounding when humans first reached the Americas.
The footprints are visible and different, imprinted in what was once the mud of what is now an ancient lake bed in New Mexico. The first test, in which sediments were layered and frozen into stone, was to determine the age of the prints by carbon dating. Since footprints are not organic material, the scientists used the seeds of a lake plant called Ruppia Cirrhosa. The seeds were found in a layer of sediment around the fingers. Genetic analysis estimates their age to be between 23,000 and 21,000 years old. However, these initial results raised some doubts among researchers, especially given their radical revision of knowledge on migration.
Loren Davis, an archaeologist at Oregon State University who was not involved in the study, said he was concerned that the ancient carbon-14 in the lake water came from plants producing seeds. To address these concerns, the researchers added two new sessions consistent with previous findings. They took pollen samples from the surrounding sediments and found that carbon competes with the seeds. Because trees grow in the ground, their pollen does not absorb carbon. Quartz grains were also collected and tested by optically stimulated luminescence (OSL) dating. The results showed that the rocks were exposed to light between 21,400 and 18,000 years ago. Despite this well-known fact, some scientists still believe that erosion can move old rocks from above. However, new evidence has been discovered that clearly shows that humans may have lived in North America as early as 16,000 years ago. I hope further testing will give me more answers.