Recent studies of ancient DNA found that the first humans who got into America might not have gone through the ice-free corridor after all, which was previously the most believable viewpoint.
If you ask any child how the first humans got into Americas, they would probably answer that these humans crossed a land that connected Alaska and Siberia, going all the way down south as glaciers had molten during the final years of the last ice age. The previous studies of science and history concurred with this conclusion.
With their most recent study, this does not seem to be the case, after all. Recent evidence came to light that dry lands free from ice were impossible to pass through until the time when humans had already been staying in the Americas.
This makes the child's answer wrong, and that the first humans 12,000 years ago should have taken an entirely different route in order to get to the Americas.
Researchers and scientists have long assumed that the first men who got into America traveled through Beringia, which is a dry region that existed when the ice age had lower sea levels, and is presently submerged in water, according to Science Mag. This was at the far north part of America, and the route which these first humans took has always been a mystery and an open-ended question.
Recent discoveries, however, suggest otherwise, because it is becoming more evident that humans have already settled in the Americas long before the glaciers became dry, which is around two to three millennia before the final years of the ice age. This means that the ice-free corridor was not viable for these inhabitants to pass through at the time.
With the discovery of new ancient DNA that has been preserved, scientists were able to trace back in time when plants and animals first appeared in the area, which is estimated to be about 12,000 years ago. This was 3,000 years too late for ancient Americans who arrived about 15,000 years ago, according to Nature.
It is currently presumed that they might have trekked through what they call the "coastal route", which led to the west coast of the U.S. This route is postulated to be already submerged in the ocean at present day, but its existence could have been entirely possible many years before the formation of the ice-free corridor.
Below is an interesting video as to how ice ages are formed and other various related phenomena.