A new study finds that tools and other artifacts uncovered by archaeologists in Alaska shed light on how people first reached North America.
The excavated evidence of prehistoric migration is approximately 600 years older than similar artifacts from the Clovis culture, whose members settled further south, including in what is now New Mexico.
Those similarities led researchers to conclude that the people who left the Alaska artifacts were ancestors of the Clovis culture. That suggests the Clovis ancestors may have crossed a land bridge that once connected Asia and North America, rather than following a coastal route as previously thought.
Because stone artifacts associated with the Clovis culture date to about 13,400 years ago, archaeologists spent much of the 20th century assuming Clovis represented the first migrants from Asia to North America. But over the past few decades, other research has shown that people reached the continent earlier.
More Questions Arise
It remained unclear how the predecessors of the Clovis culture reached the New World. For a long time, researchers thought they came across the Bering land bridge, which formed when sea levels dropped during the last Ice Age (roughly 2.6 million to 11,700 years ago). Those migrants would have crossed that landmass and then moved south through an ice-free corridor — the same corridor where the Clovis culture later developed.
But some scientists have questioned whether the corridor in present-day Canada was truly ice-free when the Clovis predecessors tried to move through it. That debate gave rise to alternative theories that the first migrants traveled different routes, including coastal paths.
Answers Are Forthcoming
Scientists analyzed archaeological material from the Tanana Valley in central Alaska. Excavations there have been ongoing for more than four decades, producing a large number of artifacts left by ancient Alaskan hunters of woolly mammoths.
Researchers focused on recent discoveries at the Holtzman site in the heart of the Tanana Valley. Notably, they examined artifacts dating back about 14,000 years, including a hammer used to make stone tools and an almost complete object recovered from the site. The team concluded that the area may be among the oldest human occupation sites in North America.
Excavation participants say the artifacts have been exceptionally well preserved in Alaska’s cold climate. “For most of the year, they remained frozen. We also discovered ancient plant DNA and even a fragment of bison wool dating back 13,600 years. Such a level of preservation of organic material is quite rare,” said Katherine Krasinski, a co-author of the study and an archaeologist at Adelphi University, in an interview with Live Science.
Her colleague Brian Wigle added, “New data from Alaska confirms that the first people arrived in central North America via an inland route through an ice-free corridor.”
In other words, the first migrants crossed the Bering land bridge from Asia to Alaska and then headed south through the ice-free corridor.
The findings were published in the journal Quaternary International.
