America's early people may have come by boat from
Asia
Researchers at an OMSI symposium present evidence of ancient coastal
routes,
possibly used earlier than once thought
By Richard L. Hill of The Oregonian staff
Toss out those old textbooks about America's first immigrants.
New evidence suggests the earliest people in the
Western Hemisphere may have arrived by boats
along coastal routes from Asia to North America
rather than just across an ancient ice bridge that linked
the two continents. They also may have arrived earlier
than previously thought.
Eight leading U.S. and Canadian researchers
presented those views Saturday at a daylong
symposium -- "Peopling of the Americas: The Pacific
Rim Hypothesis" -- in the Oregon Museum of Science
and Industry. The symposium was offered in
conjunction with OMSI's "Missing Links-Alive!"
exhibit on human origins that runs through Sept. 7.
The scientists said emerging evidence from
archaeological sites indicates that people in
skin-covered boats moved along the Pacific coast into
Alaska and northwest Canada and eventually down to
Peru and Chile during the past ice age, which ended
about 10,000 years ago. A conservative estimate is
they began migrating about 15,000 years ago.
"The 'Clovis-first' theory is dead," said Robson
Bonnichsen, director of the Center for the Study of
the First Americans at Oregon State University. The
decades-old theory holds that mammoth hunters
crossed into North America from Siberia about
11,500 years ago when the two regions were
connected by a land bridge exposed when the sea
level dropped during the ice age. Named after
distinctive stone-tipped weapons that were found near
Clovis, N.M., in the 1930s, the theory holds that a
group of hunters traveled down an ice-free corridor
between ice sheets in western Canada, then spread
throughout the hemisphere.
Bonnichsen, a longtime critic of the theory, said a
12,500-year-old site excavated near Monte Verde,
Chile, has led researchers to examine how the first
Americans spread so quickly throughout the
Americas. One of the most plausible ways, he said,
was by boat.
"The coastal environment would have provided more
subsistence than an interior route," Bonnichsen said.
"Current thinking is there were some refugia along the
coast, spots that weren't glaciated. Coastal routes
provide for easier, faster movement of people."
Rolf W. Mathewes, a professor of biological sciences
at Simon Fraser University in British Columbia, said a
study of the ancient environment shows that the
Pacific coastline 10,000 to 15,000 years ago was a
"much better option of travel" than across a frigid
interior route.
Mathewes described the "lost world" of a coastal strip
of land from Alaska to the Queen Charlotte Islands
off British Columbia that is now under more than 300
feet of water. He said glaciers didn't go all the way to
the coast in many spots, providing vegetated
"steppingstones" where maritime travelers could
survive. He said food would have been plentiful from
the ocean, as marine mammals, salmon and shellfish
were abundant.
He said that 14,000 years ago, the present Hecate
Strait between Queen Charlotte Islands and the
mainland was a treeless, flat terrain covered with
herbs, roots and other vegetation such as crow
berries that provided an abundant food resource in
the summer. Driftwood would have provided fuel for
fire.
"About 12,000 years ago, the environment changed
dramatically, and the open landscape was colonized
by trees," Mathewes said. "This perhaps would have
been when people made a final push south. A
forested environment would have been more difficult
to live in."
E. James Dixon, curator of archaeology for the
Denver Museum of Natural History, said the concept
of an interior, ice-free corridor is flawed and that a
coastal route "would have been much more viable" for
moving families and supplies.
Dixon and other scientists have been investigating
coastal caves in southeast Alaska, looking for
evidence of early inhabitants. In 1996, they found the
bones of a 23-year-old man in a small cave on Prince
of Wales Island. Radiocarbon dates indicate the
remains as being between 9,200 and 9,800 years old.
Tests show the man's diet primarily consisted of
marine mammals such as seals and otters.
"These are the oldest human remains found in
Alaska," Dixon said, "and we're seeing a pattern
emerge of sites all along the coast showing human
habitation."
Investigating the coastal migration theory is
challenging, however. Sea level has risen more than
300 feet along the North American west coast since
the end of the ice age, submerging whatever sites
might have been there. Thick forests also have
covered the area, making exploration difficult. No
evidence of skin boats has been found; the
Northwest's rainy condition quickly decomposes
organic material.
Michael J. Moratto, an archaeologist at California
State University at Fresno, described several
locations in California as being possibly inhabited by
early humans as long as 14,000 years ago.
Moratto said the best archaeological site is Daisy
Cave, on an island in the Santa Barbara Channel off
southern California. He said archaeologist Jon M.
Erlandson of the University of Oregon has excavated
cultural evidence dating back nearly 12,000 years at
Daisy Cave. "His work implies that watercraft were
being used as long ago as that," he said.
Ruth Gruhn, professor emeritus in the anthropology
department at the University of Alberta, said
numerous coastal sites in Peru, Ecuador and Chile are
being studied that are 10,800 to 12,000 years old.
At least three, and possibly four, migrations took
place, said C. Loring Brace, a professor of
anthropology at the University of Michigan. An expert
on skull and facial features, he said some of the
remains he's studied appear to be related to the
ancient Ainu of Japan, and others are related to
people in northeast Asia, southeast Asia and China.
"It's quite clear that different migrations brought
different groups of people," he said.