Haplogroup D-M55
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 | |
|---|---|
| Possible time of origin | 45,357 (95% CI 52,258 - 39,364) ybp 45,200 (95% CI 48,500 <-> 42,000) ybp |
| Coalescence age | 21,434 (95% CI 24,812 - 18,513) ybp 21,000 (95% CI 22,800 <-> 19,300) ybp |
| Possible place of origin | possibly Japanese archipelago |
| Ancestor | D-M174 |
| Defining mutations | M55, M57, M64.1, M179, P37.1, P41.1, P190, 12f2b |
| Highest frequencies | Japanese people, Jōmon people, Ainu people、 Ryukyuan people |
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 approx. 30,000 ~ 35,000 ybp) are considered as separate haplogroups. Haplogroup D-M55 may have been born in Japan at any time between its MRCA with D-Y34637 (found in present-day Onge and Jarawas) about 45,000 years ago and the MRCA of all extant branches of D-M55 about 21,000 years ago.
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.