Origin: A Genetic History of the Americas

archaeological evidence of people living there after the LGM, during the
Late Glacial period (~14,000 to 12,000 years ago), but claims of earlier
human habitation are not accepted by the majority of archaeologists, and
even potential candidate sites are very rare.
Some archaeologists are comfortable with the assumption that there are
gaps in the currently known archaeological record of Alaska. In other
words, they believe that the earliest (well-accepted) archaeological evidence
of people in Alaska, which dates to about 14,200 years ago, is much
younger than the actual date when people first arrived. They claim that the
archaeological record of Alaska is biased in two ways: First, much of
central Beringia (the Bering Land Bridge) and the coastal regions that
would have been above sea level during the LGM are now underwater and
inaccessible. Second, because so much of it is remote and difficult for
excavation teams to access, only a tiny fraction of present-day Alaska has
been studied archaeologically. Enormous expanses of land have yet to be
surveyed for archaeological sites. Therefore, they argue, while one cannot
assume people were there based on the traces of indirect evidence found
thus far, it’s far too early to definitively say anything about when people
were first in eastern Beringia, especially considering that the first
populations would likely have been small and dispersed, leaving a very
light archaeological footprint (3). In other words, we are looking for very
small needles in a very large haystack.
But other archaeologists are uncomfortable with that assumption.
Instead of hypothesizing about sites that have yet to be found, they argue,
we should look at the story the existing archaeological record of Alaska
tells us.
They believe that the archaeological record within Alaska—particularly
the lithics present at late Pleistocene sites—supports a later peopling model.
They interpret a set of archaeological sites in interior Alaska around the
middle Tanana and Nenana Valleys—the earliest undisputed sites in Alaska
—as the traces of the earliest human presence in the Americas. In this
chapter, we will explore this alternative model, the evidence it rests upon,
and the assumptions it makes.