|
The
is
notable,
as
|
|
|
|
|
The is notable, as the paper sugtgses that basal mtDNA C and D haplogroups should have been emerging somewhere in the general vicinity around the time of Jomon settlement of Japan ca. 30,000 years ago. Since the archaeological record in Japan is so clear, and the history of migration prior to the historic era is so thin, this example is one of the most helpful in putting minimum dates on lineages that are not dependent upon mutation rates."The matrilineal side (mtDNA) is more varied. There 15 main lineages and many more subclades or minor haplogroups. Those of typical Sino-Korean origin are haplogroups A (mostly A4 and A5), B (mostly B4 and B5), C, D (mostly D4 and D5), F, M8a, M9, M10, M11 and Z. Together they are present in 67% of the Japanese population. M7, although present in most of East Asia, is usually present as M7a in Japan, and has been associated with the Jomon and Ainu people. Haplogroup N9b is unique to Japan[.] N9a is found in Southeast Asia, parts of China, and throughout Japan, but is absent from Korea or Eastern China, and is consequently also surely of Jomon origin. Haplogroups G and Y are normally found in Western and Eastern ends of Siberia. These lineages are more common among the Ainu, both inside and outside Japan. The Ainu would have acquired these haplogroups through population exchange (intermarriages, probably) with their Siberian neighbours. . . .[A] few samples of haplogroup D1 were found in skeletons from the Jomon period (although N9b was the dominant lineage). This is interesting because D1 is normally not found among East Asians but among Native Americans. . . . D1 is now extremely rare in the modern Japanese population, if it still exist at all.. The most likely explanation is that D1 first appeared in Siberia then migrated to the Americas, and that a few women carrying this lineage married into other Siberian tribes that eventually came into contact with the Ainu then Jomon people, after many generations of geographic drift."The linked source doesn't make clear the age of the Jomon ancient mtDNA D1 specimens, which could be anywhere in the time range from 30,000 years ago to 2,000 years ago. An ancient DNA D1 specimen late in that range (particularly if it is after Austronesian, Paleoeskimo and/or Inuit migrations established the existence of viable long distance sea travel in the region) together with its low frequency in Japan would suggest that D1 was not part of the founding Jomon mix and arrived through minor admixture events after Jomon populations had stabilized near their peaks. On the other hand, if the specimen is very old, one might favor a theory that mtDNA D1 was present at a very low frequency in the founding population and simply wasn't very successful, perhaps due to random chance (or at any rate for reasons other than selective genetic advantage).
|
|
|
|
|
|
|
|
|
(VISITOR) AUTHOR'S NAME Santos
MESSAGE TIMESTAMP 15 december 2014, 08:46:34
AUTHOR'S IP LOGGED 117.169.1.75
|
|
|
|