24
2 The Genetic Context
The dominant Polynesian Y haplotype (50–80 percent) belongs to a widespread ancient
Asian ‘haplogroup 10’ (Hg10) defined by an RPS4y marker. An early introduction to Asia
and Australia in the Late Pleistocene (Oppenheimer 2003: 184–193), Hg10 is mainly found
in those regions as locally mutated derivatives, although it is notably absent from Taiwan
and the Philippines. The root ancestral form has been found only in India, Borneo and
Wallacea – the latter a region where Hg 10 has acquired a new Oceanic mutation M38. M38
is the only Hg10 type found in the rest of the Pacific. This could be the male analogue of
the Polynesian Motif: it is ultimately Asian, may originate in early Holocene Wallacea or
north coastal New Guinea, is absent from the New Guinea highlands, and is common in
Polynesia. Age estimates are c. 11,500 years for the western Pacific, with a later expansion
signal dated c. 5000 BP. In Polynesian groups a strong expansion signal appears dated to c.
2,200 BP, indicating multiple pulsed expansions at different times (Kayser et al. 2000).
(We note that the expansion signal dated to 2,200 BP coincides with what we
term “second-wave” Spice Island migrations, which followed a 600-year hiatus
in long-distance voyaging caused by a severe cold period between 1000 BC and
400 BC.)
Recent genetic evidence – most notably the mitochondrial studies of Trejaut
et al. [21] and of Friedlaender et al. [10] – have affirmed significant mitochondrial links between the nine indigenous Austronesian-speaking tribes of Taiwan and
populations in Luzon, the Philippines and the Moluccas or Spice Islands. However,
far from supporting the Out of Taiwan hypothesis, the new evidence raises questions about the timing of gene flow between Taiwan and the Spice Island region.
Estimates for coalescence times for the new haplogroups (B4a1a and B4a1a1) studied by Trejaut et al. and Friedlaender et al. establish genetic links, possibly dating
back to the late Pleistocene or early Holocene. The timing for the evolution of the
mitochondrial mutation np 14022 in the Moluccas that defines the later haplogroup
B4a1a1 is dated between 11,500 and 6,800 years ago. This mutation separates Spice
Islanders, coastal Papuans and Polynesians from populations in Taiwan, Luzon and
the Philippines, implying that there is no modern evidence for significant genetic
interactions affecting mitochondrial DNA taking place between these two groups of
populations after this time. It thus fails to support the hypothesis of a slow Taiwanese
migration via the Philippines (c. 5,500 BP) to Near Oceania (c. 3,600 BP).
The Express Train to Polynesia implies both that the Han Chinese invasion of
Taiwan is to be read as a Neolithic expansion of agriculturalists and that the Lapita
migration was part of that expansion. But, as we have noted, it is not the Han
Chinese (who today form 98.5% of Taiwan’s population) who are linked through
their mitochondrial genes with populations in Wallacea. It is the nine indigenous
Austronesian-speaking Taiwanese tribes that possess this link and their history for
the past 7,000 years, far from being one of expansion, has been one of genetic and
linguistic isolation. As evidence of this persisting isolation, one tribe, the Bunum,
practised head-hunting until the early 20th century [22]. The long isolation of the
indigenous Austronesian-speaking tribes in Taiwan appears to have led to the kind
of genetic and linguistic differentiation that Friedlaender et al. see as typical of
isolated inland tribes in larger islands [23]. Isolation can account both for the evolution of nine separate Austronesian languages, one per tribe, and for the preservation
in Taiwan of ancient maternal lines whose coalescence times suggest they stretch
2 The Genetic Context
The dominant Polynesian Y haplotype (50–80 percent) belongs to a widespread ancient
Asian ‘haplogroup 10’ (Hg10) defined by an RPS4y marker. An early introduction to Asia
and Australia in the Late Pleistocene (Oppenheimer 2003: 184–193), Hg10 is mainly found
in those regions as locally mutated derivatives, although it is notably absent from Taiwan
and the Philippines. The root ancestral form has been found only in India, Borneo and
Wallacea – the latter a region where Hg 10 has acquired a new Oceanic mutation M38. M38
is the only Hg10 type found in the rest of the Pacific. This could be the male analogue of
the Polynesian Motif: it is ultimately Asian, may originate in early Holocene Wallacea or
north coastal New Guinea, is absent from the New Guinea highlands, and is common in
Polynesia. Age estimates are c. 11,500 years for the western Pacific, with a later expansion
signal dated c. 5000 BP. In Polynesian groups a strong expansion signal appears dated to c.
2,200 BP, indicating multiple pulsed expansions at different times (Kayser et al. 2000).
(We note that the expansion signal dated to 2,200 BP coincides with what we
term “second-wave” Spice Island migrations, which followed a 600-year hiatus
in long-distance voyaging caused by a severe cold period between 1000 BC and
400 BC.)
Recent genetic evidence – most notably the mitochondrial studies of Trejaut
et al. [21] and of Friedlaender et al. [10] – have affirmed significant mitochondrial links between the nine indigenous Austronesian-speaking tribes of Taiwan and
populations in Luzon, the Philippines and the Moluccas or Spice Islands. However,
far from supporting the Out of Taiwan hypothesis, the new evidence raises questions about the timing of gene flow between Taiwan and the Spice Island region.
Estimates for coalescence times for the new haplogroups (B4a1a and B4a1a1) studied by Trejaut et al. and Friedlaender et al. establish genetic links, possibly dating
back to the late Pleistocene or early Holocene. The timing for the evolution of the
mitochondrial mutation np 14022 in the Moluccas that defines the later haplogroup
B4a1a1 is dated between 11,500 and 6,800 years ago. This mutation separates Spice
Islanders, coastal Papuans and Polynesians from populations in Taiwan, Luzon and
the Philippines, implying that there is no modern evidence for significant genetic
interactions affecting mitochondrial DNA taking place between these two groups of
populations after this time. It thus fails to support the hypothesis of a slow Taiwanese
migration via the Philippines (c. 5,500 BP) to Near Oceania (c. 3,600 BP).
The Express Train to Polynesia implies both that the Han Chinese invasion of
Taiwan is to be read as a Neolithic expansion of agriculturalists and that the Lapita
migration was part of that expansion. But, as we have noted, it is not the Han
Chinese (who today form 98.5% of Taiwan’s population) who are linked through
their mitochondrial genes with populations in Wallacea. It is the nine indigenous
Austronesian-speaking Taiwanese tribes that possess this link and their history for
the past 7,000 years, far from being one of expansion, has been one of genetic and
linguistic isolation. As evidence of this persisting isolation, one tribe, the Bunum,
practised head-hunting until the early 20th century [22]. The long isolation of the
indigenous Austronesian-speaking tribes in Taiwan appears to have led to the kind
of genetic and linguistic differentiation that Friedlaender et al. see as typical of
isolated inland tribes in larger islands [23]. Isolation can account both for the evolution of nine separate Austronesian languages, one per tribe, and for the preservation
in Taiwan of ancient maternal lines whose coalescence times suggest they stretch