Sorry if this subject has been covered before but I did a search and couldn't find anything.
A team of researchers writing in the journal Science last year had discovered fossilized footprints, probably of children and teens walking across a chalk plain. Dating of organic material at the strata of the prints gave a date of at least 21 to 23,000 years ago. Once again scientists have been forced to reconsider the accepted dates for peopling of the Americas and to put to rest the common idea that the Clovis culture came first.
"Normally, rock layers are "a nightmare" to date, says Bennett, a professor of environmental and geographical sciences. But he says that two years ago, archaeologist David Bustos, a study co-author, discovered a site where human footprints were co-mingled with a layer of sediment containing seeds from the spiral ditchgrass, an aquatic plant that could be carbon-dated. The results gave an estimate for the footprints.
Tom Higham, an archaeological scientist and radiocarbon-dating expert at the University of Vienna, who was not part of the study, called the latest findings "extremely exciting."
"I am convinced that these footprints genuinely are of the age claimed," he said, according to Nature."
[www.npr.org]
[www.sci.news]
So, I guess we can put to rest the idea that we have a good understanding of how people were migrating around the globe during the last ice age. My theory is and always has been that people were able to travel by sea using southern seas as a route while the North was largely encased in ice. These prehistoric journeys are mostly lost to our present day understanding of human dispersal around the globe.