Han Chinese - DNA Analysis

DNA Analysis

Y-chromosome haplogroup O3 is a common DNA marker in Han Chinese, as it appeared in China in prehistoric times. It is found in more than 50% of Chinese males, and ranging up to over 80% in certain regional subgroups of the Han ethnicity. However, the mitochondrial DNA of Han Chinese increases in diversity as one looks from northern to southern China, which suggests that some male migrants from northern China married with women from local peoples after arriving in Guangdong, Fujian, and other regions of southern China. Despite this, tests comparing the genetic profiles of northern Han, southern Han and southern natives determined that haplogroups O1b-M110, O2a1-M88 and O3d-M7, which are prevalent in southern natives, were only observed in some southern Hans (4% on average), but not in northern Hans. Therefore, this proves that the male contribution of southern natives in southern Hans is limited. In contrast, there are consistent strong genetic similarities in the Y chromosome haplogroup distribution between the southern and northern Chinese population, and the result of principal component analysis indicates almost all Han populations form a tight cluster in their Y chromosome. Additionally, the estimated contribution of northern Hans to southern Hans is substantial in both paternal and maternal lineages and a geographic cline exists for mtDNA. As a result, the northern Hans are the primary contributors to the gene pool of the southern Hans. However, it is noteworthy that the expansion process was dominated by males, as is shown by a greater contribution to the Y-chromosome than the mtDNA from northern Hans to southern Hans. These genetic observations are in line with historical records of continuous and large migratory waves of northern China inhabitants escaping warfare and famine, to southern China. Aside from these large migratory waves, other smaller southward migrations also occurred during almost all periods in the past two millennia. Moreover, a study by the Chinese Academy of Sciences into the gene frequency data of Han subpopulations and ethnic minorities in China, showed that Han subpopulations in different regions are also genetically close to the local ethnic minorities, and it means that in many cases blood of ethnic minorities has mixed into Han, while at the same time, blood of Han also has mixed into the local ethnicities. A recent, and to date the most extensive, genome-wide association study of the Han population shows that little geographic-genetic dispersion from north to south has occurred. Ultimately, with the exception in some ethnolinguistic branches of the Han Chinese, such as Pinghua, there is a coherent genetic structure in all Han Chinese populace.