When did humans cross into the Americas? Striking discovery in the world of science

The biggest forest fire of the year: More than 145,000 acres burned!

Scientists have announced that they have confirmed evidence showing that the transition to the Americas took place between 21,000 and 23,000 years ago.

According to a press release from the US Geological Survey (USGS), evidence of human presence in the Americas previously dated back 14,000 to 16,000 years ago.

Radiocarbon dating of seeds in fossilized footprints discovered in the US state of New Mexico in 2009 revealed that humans were present on the continent between 21,000 and 23,000 years ago.

Some archaeologists argued that the findings could be misleading, noting that the seeds of the aquatic plant Ruppia cirrhosa, which was examined in the study, could absorb carbon atoms from water. Subsequent research focused on determining the age of the land plant conifer pollen found in the footprints using the radiocarbon method.

Using at least 75 thousand pollen grains, the study found that the conifer pollen was the same age as the seeds of the Ruppia cirrhosa plant.

Scientists also used an age determination method called "optically stimulated luminescence" to determine when the quartz grains in the fossil were last exposed to sunlight. The study showed that the fossils are at least 21,500 years old.

Kathleen Springer, one of the researchers, stated that they started age determination studies with other methods while the article of the research was published when the fossils were first found, and that they were sure of the age of the footprints. The scientific article of the research was published in the journal Science.