Haplogroup D-M55 (M64.1/Page44.1) also known as Haplogroup D1a2a is a Y-chromosome haplogroup. It is one of two branches of Haplogroup D1a. The other is D1a1, which is found with high frequency in Tibetans and other Tibeto-Burmese populations and geographical close groups. D is also distributed with low to medium frequency in Central Asia, East Asia, and Mainland Southeast Asia.
Haplogroup D-M55 is found in about 33% of present-day Japanese males. It has been found in fourteen of a sample of sixteen or 87.5% of a sample of Ainu males in one study published in 2004 and in three of a sample of four or 75% of a sample of Ainu males in another study published in 2005 in which some individuals from the 2004 study may have been retested. It is currently the most common Y-DNA haplogroup in Japan if O1-F265 and O2-M122 (TMRCA 30,000âÂÂ35,000 YBP) are considered as separate haplogroups.
In 2017, it was confirmed that the Japanese branch of haplogroup D-M55 is distinct and isolated from other branches of haplogroup D since about 50,000 years ago. The split in D1a may have occurred near the Tibetan Plateau.
Among the subgroups of Haplogroup D, the ancestor of D-M55 went eastward to reach the Japanese archipelago. According to Michael F. Hammer of the University of Arizona, haplogroup D originated near the Tibetan Plateau and migrated into Japan where it eventually became D-M55. said that Haplogroup D1 came from Tibet to northern Kyushu via the Altai Mountains and the Korean Peninsula more than 50,000 years ago, and Haplogroup D-M55 (D1a2a) was born in the Japanese archipelago.
Recent studies suggest that D-M55 became dominant during the late JÃ Âmon period, shortly before the arrival of the Yayoi, suggesting a population boom and bust.
The average frequency in Japanese is about 30%. High frequencies are found in various places in Japan, especially in Hokkaidà Â, eastern Honshà «, southern Kyà «shà «, and Okinawa.
A JÃ Âmon period man excavated from Funadomari remains (about 3,800 - 3,500 YBP) in Rebun Island in Hokkaido belongs to haplogroup D1a2a2a (D-CTS220).
The analysis of a JÃ Âmon sample (Ikawazu) and an ancient sample from the Tibetan Plateau (Chokhopani) found only partially shared ancestry, suggesting a positive genetic bottleneck regarding the spread of haplogroup D from an ancient population related to the Tibetan Chokhopani sample (and modern Tibeto-Burmese groups).
By ISOGG Tree (Version: 14.151).