September 27, 2005
Linking of Languages May Speak Volumes
By NICHOLAS WADE
Linguists have devised a new way of linking languages, which they say has allowed them to reconstruct a network of the languages spoken in islands near New Guinea.
The new method is designed for languages so old that little trace of their common vocabulary remains. It forges connections between languages through grammatical features, which change less quickly than words.
With the new tool, historians may be able to peer considerably further back in time than the 5,000 to 7,000 years or so that many linguists see as the limit beyond which no sure connections can be made between languages.
The authors of the new method say the relationships they can construct may be 10,000 years or older.
The researchers, who were led by Michael Dunn, of the Max Planck Institute for Psycholinguistics in Nijmegen, Holland, have published their work in the current issue of Science.
They say that on the basis of grammatical similarities they have constructed a network of the Papuan languages spoken in the island groups east of Papua New Guinea. Traveling eastward, these are the Bismarck Islands, Bougainville and the Solomon Islands.
The grammar-derived network correctly assigns all languages to their respective archipelagos, showing it has picked up the relatedness to be expected from geography. But the network gives a puzzling placement to the Solomon Island languages.
They fall in between those of the Bismarcks and Bougainville, stepping out of the sequence expected if the islands were first occupied by people migrating from west to east.
The explanation, Dr. Dunn and his colleagues say, is that 10,000 years ago, when sea levels were much lower because of the Pleistocene ice age, Bougainville and the Solomon Islands would have been joined in a single land mass, while the Bismarcks were always separate.
This might explain the Bougainville languages' closer relationship to those of the Solomons and distance from those of the Bismarcks. It would also indicate that the grammar-based linking is picking up a signal from 10,000 years ago.
The Solomons are well known as the arena in which American and Japanese forces clashed in World War II in the battle at Guadalcanal. They are of interest to linguists for a different reason.
They lie at the very end of a migration route that might have been taken by the first modern humans, who left Africa some 50,000 years ago, and that few others may have reached.
These early people reached Australia 5,000 years later and were established in the Bismarcks and Solomons by 35,000 years ago. A much later group of emigrants, people speaking Austronesian, is known to have reached the islands about 4,000 years ago from a home base in Taiwan.
The Austronesian languages are a distinctive family with many shared words. Many Papuan languages, by contrast, have lost any obvious relationship with each other, a sign of great antiquity.
William Foley, a linguist at the University of Sydney, has noted that the word structure of the Bougainville languages resembles those of Trans New Guinea, the languages spoken in a broad swath across the New Guinea highlands.
He has also found similarities between the Trans New Guinea languages and those of Australia, to which the island of Papua New Guinea was joined until 8,000 years ago in a super continent known as Sahul.
Could all these languages be echoes of the ancient tongue spoken by the first humans to arrive in Sahul? "That is part of the reason why we care about these languages and continue to look at them," Dr. Dunn said.
His work is part of a joint project by British, Dutch, German and Swedish researchers to study the languages, genetics and archaeology of people in the Bismarcks-Solomons archipelago and see if the history of Papuan speakers can be reconstructed.
Although all the non-Austronesian languages in the region are called Papuan, they do not have much in common with each other because time has erased most of their common vocabulary. Whether the remaining shared vocabulary is enough to establish relationships between the languages is a matter of dispute.
The late Joseph Greenberg, the great classifier of the world's languages, believed that all the Papuan languages, along with those of Tasmania and the Andaman Islands, belonged to a family he called Indo-Pacific.
Many linguists, including Dr. Dunn, reject Dr. Greenberg's grouping on the grounds that there are not enough remaining words of clearly common origin to define relationships between the Papuan languages. That was why Dr. Dunn's team sought to link the languages through grammatical features, borrowing a statistical approach used by biologists to connect related objects in the most plausible way.
Dr. Merritt Ruhlen, a colleague of Dr. Greenberg's, criticized Dr. Dunn's team for calling the languages of the region "a group of hitherto unrelatable isolates," since Dr. Greenberg had related them on the basis of their shared vocabulary and with much the same result as the grammar-based method.
But Russell Gray, a biologist at the University of Auckland in New Zealand who has pioneered applying biological tree-drawing methods to linguistics, writes in Science that the grammar-based approach will be "widely emulated" by researchers studying languages in other regions of the world. The new technique is "very promising," he said in an e-mail message.
http://www.nytimes.com/2005/09/27/science/27lang.html