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From [2].

From AMS Ko et al, “Early Austronesians: Into and Out of Taiwan,” AJHG 94, 2014 [1].

Genetic analyses say that the Liangdao Man “has the most ancestral haplogroup E sequence among extant Austronesian speakers [1].”

Liangdao man. Photo from [1].

Liangdao man. Photo from [1].


Liangdao who?

In December 2011, skeletal remains were discovered in Liangdao Island of the Matsu archipelago (between China and Taiwan) during a road construction. The remains, the earliest skeleton ever unearthed in the fetal burial position, was buried with shells, pottery shards, bone tools and human parietal bones [2].

Carbon dating of a thoracic rib gives a date of 8,000-8,300 years before present. This makes the find the oldest skeleton of the Neolithic era that has ever been discovered in Taiwan.

Genetic analyses from the DNA extracted from the foot phalanx and femur of the Liangdao man were done at the Max Planck Institute for Evolutionary Anthropology in Germany. The analyses reveal clues that enable researchers to “reconstruct a history of early Austronesians arriving Taiwan and leaving the island to spread throughout Island Southeast Asia, Madagascar and Oceania [1].”

Archaeological and linguistic evidences have pointed out that Austronesians came from southern China but genetic clues have never been conclusive. For one, the haplogroup E, the haplogroup associated with the Austronesian expansion, has been dated to be more than 30,000 years old by the rho method (a statistical estimate) and a constant molecular clock and has been traced in Island Southeast Asia (ISEA) [3]. However, “deeper branches of E1a1 are found within the Taiwanese aboriginal population greater than in the Philippines which reverses the pattern of genetic variation expected if E1a1 expanded from ISEA, if indeed the haplogroup E came from ISEA [4].”

Now, using Bayesian dating (another statistical estimate) with ancient DNA calibration provided by the Liangdao find, researchers say that the haplogroup E arose around 8,000-11,000 years ago [1]. The researchers add that this highlights “the value of incorporating ancient DNA information into molecular dating.”

Haplogroup E is not observed in China and therefore, “the occurrence of this haplogroup at the Liangdao man’s location is highly unusual [1].” Moreover, the Liangdao man could not possibly come from (mainland) Taiwan as the haplogroup M9 (the haplogroup where the haplogroup E evolved from) has never been detected there. M9 is distributed along coastal China. Haplogroup E, however, can be found in Austronesian-speaking groups.

The researchers “suggest that M9 differentiated to E lineages near Fuzou (see map above) and that the haplogroup E lineages are associated with early Austronesians and subsequent dispersal of Austronesian languages.”

They compared the DNA extracted in Liangdao man to the DNA from Taiwanese aboriginals, the Philippines, Malaysia, Indonesia, and Melanesia.  The closest match happened with two aboriginal Taiwanese.

They found that the Liangdao man and the aboriginal Taiwanese shared common ancestry between 8,000 to 10,000 years ago.  Their simulation showed a population expansion during that time. They said, “when the Austronesians diverged from the Han ancestors and expanded in Taiwan, haplogroup E increased in frequency outside of China[1].”

Based on complete mtDNA sequences, the early Austronesian dispersed southward in Taiwan with the northern groups diverging earlier (~5,00 years ago). Then there was a split between the central and southern groups by 5,200 years ago.

The simulations they made for out of Taiwan placed the split of the proto-Malayo-Polynesian at around 4,100-4,200 years ago.  During these times however, the tribes in Taiwan where still not formed. Hence, the researchers said that there was a rapid colonization of the island of Taiwan and the differentiation happened afterwards.

Aboriginal Taiwanese tribal relationships based on complete mtDNA sequences from [1]. The Filipino is in the Malayo-Polynesian branch.

Aboriginal Taiwanese tribal relationships based on complete mtDNA sequences from [1].
The Filipino is in the Malayo-Polynesian branch.

There is a good agreement between the genetic relations the researchers obtained and relationships proposed by linguistic models.

The researchers conclude that they can neither be sure of the language of the Liangdao man nor if he contributed to the spread of rice associated with Austronesian expansion.  But they are sure that “he carries an ancestral haplogroup E mtDNA sequence that strongly links him with contemporary aboriginal Taiwanese, he provides a link to southern China, and he has the most ancestral haplogroup E sequence found among extant Austronesian speakers.”

Reference:

[1] Ko, A., Chen, Y., Fu, Q., Delfin, F., Li, M., Chiu, L., Stoneking, M., Ko, C. (2014). Early Austronesians: Into and Out Of Taiwan, The American Journal of Human Genetics, 94 (3) 426-436. DOI: http://dx.doi.org/10.1016/j.ajhg.2014.02.003

[2] http://www.chinapost.com.tw/taiwan/national/national-news/2012/04/03/336596/Remains-of.htm

[3] Soares, P., Trejaut, J., Loo, J., Hill, C., Mormina, M., Lee, C., Chen, Y., Hudjashov, G., Forster, P., Macaulay, V., Bulbeck, D., Oppenheimer, S., Lin, M., & Richards, M. (2008). Climate Change and Postglacial Human Dispersals in Southeast Asia Molecular Biology and Evolution, 25 (6), 1209-1218 DOI: 10.1093/molbev/msn068

[4] Tabbada, K., Trejaut, J., Loo, J., Chen, Y., Lin, M., Mirazon-Lahr, M., Kivisild, T., & De Ungria, M. (2009). Philippine Mitochondrial DNA Diversity: A Populated Viaduct between Taiwan and Indonesia? Molecular Biology and Evolution, 27 (1), 21-31 DOI: 10.1093/molbev/msp215