Thursday, October 05, 2006

mtDNA of Aboriginal Southeast Asians

A new study co-written by "Eden in the East" author Stephen Oppenheimer showed that about half the mtDNA of the Senoi population of Malaya, and a significant population of "Aboriginal Malays" originates in Indochina. The Semang group has mostly deep-rooted mtDNA from the Malay Peninsula.

Paul Kekai Manansala

Mol Biol Evol. 2006 Sep 18;

Phylogeography and Ethnogenesis of Aboriginal Southeast Asians.

Hill C, Soares P, Mormina M, Macaulay V, Meehan W, Blackburn J,
Clarke D, Raja JM, Ismail P, Bulbeck D, Oppenheimer S, Richards M.

Studying the genetic history of the Orang Asli of Peninsular
Malaysia can provide crucial clues to the peopling of Southeast Asia
as a whole. We have analyzed mitochondrial DNA control-region and
coding-region markers in 447 mitochondrial DNAs (mtDNAs) from the
region, including 260 Orang Asli, representative of each of the
traditional groupings, the Semang, the Senoi and the Aboriginal
Malays, allowing us to test hypotheses about their origins. All of the
Orang Asli groups have undergone high levels of genetic drift, but
phylogeographic traces nevertheless remain of the ancestry of their
maternal lineages. The Semang have a deep ancestry within the Malay
Peninsula, dating to the initial settlement from Africa >50,000 years
ago. The Senoi appear to be a composite group, with approximately half
of the maternal lineages tracing back to the ancestors of the Semang,
and about half to Indochina. This is in agreement with the suggestion
that they represent the descendants of early Austroasiatic speaking
agriculturalists, who brought both their language and their technology
to the southern part of the peninsula approximately 4000 years ago,
and coalesced with the indigenous population. The Aboriginal Malays
are more diverse, and although they show some connections with island
Southeast Asia, as expected, they also harbor haplogroups that are
either novel or rare elsewhere. Contrary to expectations, complete
mtDNA genome sequences from one of these, R9b, suggest an ancestry in
Indochina around the time of the Last Glacial Maximum, followed by an
early-Holocene dispersal through the Malay Peninsula into island
Southeast Asia.