 The frequencies of Haplogroup O-M119 among various East Asian and Austronesian populations suggest a complex genetic history of the modern Han populations of southern China.Although Haplogroup O-M119 occurs only at an average frequency of approximately 4% among Han populations of northern China and peoples of southwestern China and Southeast Asia who speak Tibeto-Burman languages, the frequency of this haplogroup among the Han populations of southern China nearly quadruples to about 15-23%.The frequency of Haplogroup O-M119 among the Southern Han has been found to be slightly greater than the arithmetic mean of the frequencies of Haplogroup O-M119 among the Northern Han and a pooled sample of Austronesian populations.