Linguistically and culturally, thes

Linguistically and culturally, these Lapita peoples are seen as the
immediate ancestors of the Polynesians (Kirch and Green, 2001).
The accumulating biological data in the early and mid 1990s also
supported this view of ultimate Southeast Asian, and more specifically,
Taiwanese origins for Polynesians, and presumably their
more immediate Lapita ancestors. In particular, a combination of
mtDNA mutations was identified, with the characteristic single
nucleotide polymorphisms (SNPs) at nucleotide positions 16217,
16247 and 16261 and the nine base pair (bp) deletion in the COII/
tRNALys intergenic region, the combination of which defined the
B4a1a1a haplogroup (note: Phylotree build 16 (http://www.
phylotree.org/) has resulted in a major revision of the B4a1a1 and
derived haplogroups). This haplogroup was found at high frequency
throughout the Pacific, but particularly in Polynesia, where
its distribution has been described as near ubiquitous and thus it
became referred to as the Polynesian motif (PM) (Hagelberg and
Clegg, 1993; Melton et al., 1995; Redd et al., 1995). The ancestral
haplogroup, B4a1a, is clearly of Asian origin and is found in Taiwan
and throughout Island Southeast Asia and the western Pacific, and
this was seen initially as supporting an ‘Out of Taiwan model for
Polynesian origins’ (Trejaut et al., 2005; Friedlaender et al., 2007).
However, more recently, the immediate origin and age of B4a1a1a
is a topic of much debate (Tabbada et al., 2010; Soares et al., 2011).
The B4a1a1a haplogroup is not present in Taiwan or the Philippines
and, based on analyses of complete mtDNA genomes, Soares et al.
(2011) argue that the Polynesian motif and its immediate ancestral
lineages (B4a1a1) evolved within the Bismarck Archipelago
some 6000e8000 years ago, several thousand years before the
appearance of the Lapita cultural complex in that same location.
There is much debate, however, regarding the reliability of estimates
of coalescence dates, and it is possible that the haplogroup
was present at low frequency in Island Southeast Asia prior to
Austronesian expansion and was subsequently spread causing an
increased frequency as a result of that expansion into Near and
Remote Oceania. (Note that build 16 of phylotree, released in
February 2014, has, based on a recent publication [Duggan andStoneking, 2013], declared that the mutation defining B4a1a1a,
16249G, is no longer a reliable defining mutation for the haplogroup
and thus the nomenclature for this haplogroup and derived
subgroups has been updated).