It has been found in about 6% (2.3% to 16.7%) of modern males sampled in Japan and has been considered to be a Y-DNA haplogroup descended from Jōmon people.[5][6] Elsewhere, it has been observed among academic studies only in one individual in a sample collected on Jeju Island of South Korea[7] and in commercial testing in one individual who has reported an origin in Liaoning province of China and one individual who has reported an origin in Seoul, South Korea.[8]
The MRCA with its sister haplogroup C-V20 dates back to 40,000[1] to 50,000[2] years ago. Diffusion of existing subtypes of C-M8 is estimated to have begun about 12,000 years ago.[3]
C1a1 is found in the Jōmon people and are linked to the Jomon people who came from the south route.
^ abZhong H, Shi H, Qi XB et al. (July 2010). "Global distribution of Y-chromosome haplogroup C-M130 reveals the prehistoric migration routes of African exodus and early settlement in East Asia". J. Hum. Genet. 55 (7): 428–35. doi:10.1038/jhg.2010.40. PMID20448651.
^ abG. David Poznik, Yali Xue, Fernando L. Mendez, et al., "Punctuated bursts in human male demography inferred from 1,244 worldwide Y-chromosome sequences." Nature Genetics 2016 June ; 48(6): 593–599. doi:10.1038/ng.3559.
^ abHammer MF, Karafet TM, Park H et al. (2006). "Dual origins of the Japanese: common ground for hunter-gatherer and farmer Y chromosomes". J. Hum. Genet. 51 (1): 47–58. doi:10.1007/s10038-005-0322-0. PMID16328082.
^Michael F Hammer; Tatiana M Karafet; Hwayong Park; Keiichi Omoto; Shinji Harihara; Mark Stoneking; Satoshi Horai (2006). “Dual origins of the Japanese: common ground for hunter-gatherer and farmer Y chromosomes”. Journal of Human Genetics 51 (1): 47 - 58. doi:10.1007/s10038-005-0322-0. PMID16328082.