Monday, October 5, 2015

Kapa plant Wauke confirms Polynesian migration theories

When Polynesians cane across the Pacific, a 5,000-year migration, they brought familiar products with them.

A new paper tracks genetically one of those products, paper mulberry, which is known in Hawai`i as wauke (Broussonetia papyrifera). 

(Image: An indication of the wide range of the wauke plant, this one was photographed within the volcanic crater of Rano Kau on Rapa Nui or Easter Island. Credit: Kuo-Fang Chung.)

And its genetic makeup in different locations across the ocean confirms modern theories of  migration from the island now known as Taiwan, through New Guinea, and eventualy into the Eastern Pacific and Hawai`i.

The paper, entitled “A holistic picture of Austronesian migrations revealed by phylogeography of Pacific paper mulberry,” was written by by Taiwan and Chile researchers Chi-Shan Chang, Hsiao-Lei Liu, Ximena Moncada, Andrea Seelenfreund, Daniela Seelenfreund and Kuo-Fang Chung.
The paper was printed in the Proceedings of the National Academy of Sciences

Various theories start the migration of the people who would be the Polynesians in South China, Taiwan, Vietnam or elsewhere in southeast Asia. 

“We test these propositions by studying phylogeography of paper mulberry, a common East Asian tree species introduced and clonally propagated since prehistoric times across the Pacific for making barkcloth, a practical and symbolic component of Austronesian cultures,” the authors write.

Wauke, whose inner bark was converted into bark cloth for clothing, ornament and other uses, may be the most widely distributed fiber product of early prehistory, the authors write.

“We demonstrate a tight genealogical link between its populations in South China and North Taiwan, and South Taiwan and Remote Oceania by way of Sulawesi and New Guinea, presenting the first study, to our knowledge, of a commensal plant species transported to Polynesia whose phylogeographic structure concurs with expectations of the “out of Taiwan” hypothesis of Austronesian expansion,” they write.

A commensal relationship is one in which two different things—in this case humans and wauke—work together to the benefit of both. Humans got clothing, and the paper mulberry got to dramatically expand its range.

The authors studied 600 or so samples of wauke tissue collected from across the Pacific, and looked at genetic variation in them. They were able to track the migration of the wauke, and thus the Polynesians, across the ocean. 

Separately, they were able to show that the earliest Taiwan residents may have brought a predecessor plant from southeast China.

© Jan TenBruggencate 2015

1 comment:

Fern said...

Very interesting!! Thanks for sharing this!