The first Homo sapiens to arrive in the Americas may have originated in a region covering today’s Hokkaido, Sakhalin and the Kuril (Chishima) islands, according to a new theory by a group of Japanese and U.S. researchers.
The anthropologists said finds from archaeological sites left by some of the earliest modern humans in North America share common features, including ancient tool technology, with items unearthed at older archaeological digs in Hokkaido.
It had been theorized that the first Americans may have originated in Beringia, an area stretching from Siberia to Alaska, which was connected by land.
Members of the research team that included a member from Tokyo Metropolitan University and another from Tohoku University said that their new hypothesis is based on archaeological evidence that was previously unavailable.
That evidence leads them to believe that the Hokkaido-Sakhalin-Kuril area is the most likely candidate site.
The scholars published their research results in Science Advances, a scientific journal.
Paleogenomic studies have indicated the group ancestral to the first Americans was formed somewhere in Northeast Asia about 25,000 years ago and underwent 4,000 to 5,000 years of geographical isolation and a population decline before arriving on the American continent some 20,000 years ago or later.
It has yet to be specified, however, where that “stillstand” occurred.
The research team members found that 10 Upper Paleolithic sites on mainland North America, which are between 18,000 and 13,500 years old, have produced stone tools that share highly similar technological features.
These resemble the lithic technology found at archaeological sites in Northeast Asia, including Hokkaido.
They also found those sites have produced projectile points that have an elliptical contour with a pointed head and an elliptical cross section with sharp blade edges.
Projectile points refer to pointed stone tools that were used as spearheads during hunting. The above-described shape of the points maximizes their piercing power and durability.
Stone tools of this design have been found in the Hokkaido-Sakhalin-Kuril area at sites up to about 20,000 years old, whereas they begin to be found at Beringian sites of only about 14,000 years ago.
Considering the chronology, it appears reasonable to assume the lithic design propagated from the Hokkaido-Sakhalin-Kuril region to mainland North America, the scholars argued.
QUESTION OF MIGRATION ROUTE
There arises the question of how Homo sapiens likely migrated from the Hokkaido-Sakhalin-Kuril area to North America.
Ice sheets were the largest, and the climate was the coldest, approximately between 29,000 and 18,000 years ago during the last glacial period.
Beringia was a polar desert at the time. No archaeological sites have been found there from that period.
The Hokkaido-Sakhalin-Kuril region, at the time, is believed to have been a peninsula extending from the mouth of the Amur River.
It is also known, meanwhile, that people on the Japanese islands of that period had seafaring skills, as islands in Okinawa and Kagoshima prefectures are home to archaeological sites that are approximately 35,000 to 30,000 years old.
The researchers on the team assume that part of a population that originated in the Hokkaido-Sakhalin-Kuril area likely followed a circum-Pacific coastal route, partially on boats.
These ancient humans moved into North America over a period of several millennia, starting about 20,000 years ago, and went on to spread across the continent.
The so-called Jomon people, who are believed to be one of the progenitor groups for today’s Japanese, likely entered Hokkaido only around 10,000 years before the present day.
The Hokkaido-Sakhalin-Kuril region’s population in question were likely not the direct ancestors of the Japanese and other peoples of today but rather a “ghost population,” who were there earlier but have since disappeared, the scholars said.
Masami Izuho, one of the research team members, said that results of archaeological studies on the Japanese islands of the corresponding period have so far been discussed, mostly by scholars in Japan, from the viewpoint of how people came to live on the Japanese islands.
However, these findings have seldom been considered by world archaeologists as a major event in global human history.
“In our latest study, we have been able to propose, as the most viable hypothesis, that Homo sapiens likely spread from the Hokkaido-Sakhalin-Kuril region to mainland North America,” said Izuho, a Tokyo Metropolitan University associate professor of archaeology.
He continued: “This hypothesis indicates that people with seafaring skills who were well-adapted to the ocean were the main actors of the expansion of modern humans onto the North and South American continents, which has been dubbed the final leg of their grand journey.”
Izuho added: “The history of the expansion of Homo sapiens did not unfold one-sidedly through the actions of continental populations. It should rather be reinterpreted as a history of technological and behavioral adaptation of populations based in island areas and of their interactions with populations based in continental areas.”
Rintaro Ono, a professor of maritime archaeology with the National Museum of Ethnology, said the research article presents a scenario that supports the “kelp highway” hypothesis on the first Homo sapiens migrants to the Americas.
The kelp highway refers to the theory that it is more realistic for the first Home sapiens to have used a coastal route than to have moved across glacial, and extremely cold, inland areas.
“The article discusses that scenario on the basis of detailed lithic analysis results and points out that the migrant population may have had origins in Hokkaido, Sakhalin or other areas nearby,” Ono said. “That’s so interesting.”
Ono said he believes it holds the chronological key that the first migration likely dated to sometime slightly more than 20,000 years ago, which falls on the coldest period.
“If that is the case, there is this question of whether reduction in resources, migrations of large animals and other consequences of global cooling prompted people to move toward the Americas,” he said. “There could also be a scenario whereby reduction in land-based resources increased people’s dependence on marine resources, which adapted them better to the ocean.”
Ono concluded: “Advances in research on the details of these questions would improve the probability and likelihood of the hypothesis, or the scenario, discussed in the paper.”
The research paper can be viewed at (https://doi.org/10.1126/sciadv.ady9545).
AloJapan.com