[tt] NYT: Pacific Islanders' Ancestry Emerges in Genetic Study

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Pacific Islanders' Ancestry Emerges in Genetic Study
http://www.nytimes.com/2008/01/18/world/asia/18islands.html

By JOHN NOBLE WILFORD

The ancestral relationships of people living in the widely
scattered islands of the Pacific Ocean, long a puzzle to
anthropologists, may have been solved by a new genetic study,
researchers reported Thursday.

In an analysis of the DNA of 1,000 individuals from 41 Pacific
populations, an international team of scientists found strong
evidence showing that Polynesians and Micronesians in the central
and eastern islands had almost no genetic relationship to
Melanesians, in the western islands like Papua New Guinea and the
Bismarck and Solomons archipelagos.

The researchers also concluded that the genetic data showed that
the Polynesians and Micronesians were most closely related to
Taiwan Aborigines and East Asians. They said this supported the
view that these migrating seafarers originated in Taiwan and
coastal China at least 3,500 years ago.

The findings were described in the online journal Public Library
of Science Genetics (www.plosgenetics.org) by researchers led by
Jonathan S. Friedlaender, professor emeritus of biological
anthropology at Temple University. He was assisted in the data
analysis by his wife, Françoise R. Friedlaender, an independent
researcher. Other participants included scientists in the islands
and at the Marshfield Clinic Research Foundation in Marshfield,
Wis.

"Our analysis," the scientists wrote, "indicates the ancestors of
Polynesians moved through Melanesia relatively rapidly and only
intermixed to a very modest degree with the indigenous
populations there."

Dr. Friedlaender of Temple said in an interview that the evidence
was "substantial" and "solves a number of issues about the
migration and settlement of Pacific people."

In particular, he and other anthropologists not involved in the
study said, the genetic research supported the "fast train"
hypothesis. Increasing archaeological and linguistic evidence in
recent years has suggested that ancestors of Micronesians and
Polynesians had moved through Indonesia and Melanesia without
having any significant contact there, culturally or genetically.

An alternative argument, the "slow boat" hypothesis, which had
some support from male Y chromosome studies, raised the
possibility that Polynesians were primarily Melanesians who had
ventured on in their outrigger canoes. And a few anthropologists
despaired of ever solving the mystery. Theirs was the "entangled
bank" hypothesis.

The new genetic research, said Patrick V. Kirch, an
anthropologist at the University of California, Berkeley, who is
an authority on Pacific cultures, was "overwhelming biological
evidence for a clear population movement out of Southeast Asia
and Taiwan to Polynesia."

Dr. Kirch, who did not participate in the genetic study, said
that it reinforced research showing that Polynesian speech
patterns were unrelated to Melanesian languages, suggesting --
along with discoveries of the distinctive Lapita pottery across
the Pacific -- links to Taiwan and China, not Melanesia. "The
combination of evidence shows we really can read this history,"
he said.

As Dr. Friedlaender said, "If it wasn't exactly an express train,
it was pretty fast, and very few passengers climbed aboard or got
off along the way."

In the research, scientists examined more than 800 genetic
markers known to be useful in distinguishing the ancestry of
people. These involved mitochondrial DNA, passed down through
females, and the Y chromosomes in males. Previous investigations
along these lines had been conducted on a much smaller scale, Dr.
Friedlaender said.

The new test results were repeatedly analyzed with a software
program recently developed to classify genetic similarities and
variations among different populations.

Primary support for the study was provided by the National
Science Foundation, the Wenner-Gren Foundation of Anthropological
Research, the National Geographic Society and the National
Institutes of Health.

Further research to confirm the history of the Pacific diaspora,
Dr. Friedlaender said, would require an expansion of genetic
tests among people in the Philippines and Indonesia, regions that
the migrants presumably passed through after leaving Taiwan more
than 3,500 years ago, ultimately reaching as far as Hawaii and
Easter Island. The Melanesians, on the other hand, probably
arrived on their islands about 35,000 years ago, sometime later
than the Aborigines reached Australia.

Years ago, a reporter who visited the Marshall Islands asked an
aging Micronesian chief where his people came from long, long
ago. "We have always been here," he replied. Now, if it matters
to them, his descendants have been given a more scientific
answer.