 The Y2 subclade has been observed in 40% (176/440) of a large pool of samples from Nias in western Indonesia, ranging from a low of 25% (3/12) among the Zalukhu subpopulation to a high of 52% (11/21) among the Ho subpopulation.Haplogroup Y has been divided into two primary subclades, Y1 and Y2.In a study published in 2016, mtDNA haplogroup Y1a was observed in an Ulchi sampled in Nizhniy Gavan, Lower Amur, whereas mtDNA haplogroup Y2a1 was observed in an Igorot from Mountain Province, Luzon Island, Philippines (sampled in Singapore) and in a Hawaiian.