5.3 Evidence from the Japanese Taro
91
of greater cold resistance by the time of the founding of the Cinnamon Route. Again
the implicit conclusion is that a spice-trading route to Japan via Palau would have
been much older.
5.3 Evidence from the Japanese Taro
The case for an early Spice Island colony in southern Japan and the case which
we develop at length in Part II for a Lapita-age first settlement of New Zealand
are both strengthened by recent innovative genetic research by Mike Hendy of
Massey University, New Zealand [3]. Just as the analysis of the haplogroups of
Polynesian commensal animals has led to a new approach to the study of human
migrations in the Pacific, Hendy has developed a new approach to the analysis of
human migrations in the Pacific through the genetic study of commensal plants.
Hendy [3] has pioneered a new way of genetically fingerprinting plants through
the study of “junk DNA” as a means of gaining a more complete picture of their
genetic history. The DNA that is involved in selection by genetic drift covers the
traces of its historical evolution. By contrast, Hendy believes, analysis of “junk
DNA” can reveal a more complete phylogenetic record. Hendy has applied this
approach to a study of the New Zealand taro.
Forty years ago Douglas Yen and Jocelyn Wheeler [4] established that one of
the varieties of taro found in New Zealand had evolved from the Japanese taro. In
1968 they mapped the relationship of taro in the Pacific and Southeast Asia according to chromosome numbers. The tropical taro cultivars found in Eastern Polynesia,
New Guinea, the eastern and southern Philippines and the Solomon Islands exclusively have a chromosome count of 2n = 28. Japan, the Ryukyus, northwestern
Philippines, eastern China, Timor, New Caledonia and New Zealand possess two
varieties, one with a chromosome count of 2n = 28 and one with a chromosome
count of 2n = 42. As Yen and Wheeler note, “The taro plant in its distribution
has been associated inevitably with man because of its universal propagation by
vegetative means” (p. 262). They comment that
If we take mainland Asia as a point of embarkation, the data (Map 1) point to three
lines of diffusion; two of 28- and 42-chromosome forms travelling northwards through the
Ryukyus to Japan, and southwards through Timor and New Caledonia to New Zealand; the
third exclusively of 28-chromosomes proceeding through northern Melanesia to Polynesia
(p. 263).
Against the counter-suggestion that the 42-chromosome form in New
Zealand may represent a European introduction, Yen and Wheeler argue that
42-chromosome specimens “(from Great Barrier Island and from Spirit’s Bay in
the extreme northern peninsula of New Zealand) cannot be ascribed confidently
to possible transfer in European times” (p. 265). The 42-chromosome taro found
in 1957 untended on the Cavalli Islands off the north coast of New Zealand similarly seems unlikely to be descended from a European import. Yen and Wheeler
imply that the 42-chromosome form was early. They suggest that it may have been
91
of greater cold resistance by the time of the founding of the Cinnamon Route. Again
the implicit conclusion is that a spice-trading route to Japan via Palau would have
been much older.
5.3 Evidence from the Japanese Taro
The case for an early Spice Island colony in southern Japan and the case which
we develop at length in Part II for a Lapita-age first settlement of New Zealand
are both strengthened by recent innovative genetic research by Mike Hendy of
Massey University, New Zealand [3]. Just as the analysis of the haplogroups of
Polynesian commensal animals has led to a new approach to the study of human
migrations in the Pacific, Hendy has developed a new approach to the analysis of
human migrations in the Pacific through the genetic study of commensal plants.
Hendy [3] has pioneered a new way of genetically fingerprinting plants through
the study of “junk DNA” as a means of gaining a more complete picture of their
genetic history. The DNA that is involved in selection by genetic drift covers the
traces of its historical evolution. By contrast, Hendy believes, analysis of “junk
DNA” can reveal a more complete phylogenetic record. Hendy has applied this
approach to a study of the New Zealand taro.
Forty years ago Douglas Yen and Jocelyn Wheeler [4] established that one of
the varieties of taro found in New Zealand had evolved from the Japanese taro. In
1968 they mapped the relationship of taro in the Pacific and Southeast Asia according to chromosome numbers. The tropical taro cultivars found in Eastern Polynesia,
New Guinea, the eastern and southern Philippines and the Solomon Islands exclusively have a chromosome count of 2n = 28. Japan, the Ryukyus, northwestern
Philippines, eastern China, Timor, New Caledonia and New Zealand possess two
varieties, one with a chromosome count of 2n = 28 and one with a chromosome
count of 2n = 42. As Yen and Wheeler note, “The taro plant in its distribution
has been associated inevitably with man because of its universal propagation by
vegetative means” (p. 262). They comment that
If we take mainland Asia as a point of embarkation, the data (Map 1) point to three
lines of diffusion; two of 28- and 42-chromosome forms travelling northwards through the
Ryukyus to Japan, and southwards through Timor and New Caledonia to New Zealand; the
third exclusively of 28-chromosomes proceeding through northern Melanesia to Polynesia
(p. 263).
Against the counter-suggestion that the 42-chromosome form in New
Zealand may represent a European introduction, Yen and Wheeler argue that
42-chromosome specimens “(from Great Barrier Island and from Spirit’s Bay in
the extreme northern peninsula of New Zealand) cannot be ascribed confidently
to possible transfer in European times” (p. 265). The 42-chromosome taro found
in 1957 untended on the Cavalli Islands off the north coast of New Zealand similarly seems unlikely to be descended from a European import. Yen and Wheeler
imply that the 42-chromosome form was early. They suggest that it may have been