Figure 2. PC analysis based on mitochondrial DNA haplogroup frequencies.

The two dimensions account for 43.4% of the total variance. Haplogroup contributions are represented by loading vectors marked on the plot as grey arrows. Populations are grouped into five clusters according to k-means. First cluster (in green): BAK, Bronze Age Kazakhstan; CWC, Corded Ware culture; SCR, Scythians from Russia; SCU, Scythians from Moldova and Ukraine, present study; SRU, Srubnaya culture; TAG, Tagar culture; UNC, Unetice culture; YAM, Yamnaya culture. Second cluster (in red): HGC, Hunter-Gatherers Central Europe; HGS, Hunter-Gatherers Southern Europe; MNG, Middle Neolithic Germany. Third cluster (in blue): AND, Andronovo culture; BAS, Bronze Age Siberia; CAT, Catacomb culture; HE, Hunter-Gatherers East Europe; PWC, Pitted Ware culture. Fourth cluster (in purple): BBC, Bell Beaker culture; CRE, Crete Minoans; FBC, Funnel Beaker culture; IAD, Iron Age Denmark; IAG, Iron Age Germany; IAK, Iron Age Kazakhstan; IAP, Iron Age Poland; MNS, Middle Neolithic Southern Europe. Fifth cluster (in orange): CHH, Western Hun, China; CHG, Gavaerg China; CHQ, Quin to Western Jin, China; CHX, Xiaohe, Xinjiang, China; CXN, Xiongnu, Mongolia; SCA, Scytho-Siberians from Altai; SCM, Pazyryk culture from Mongolia. Detailed descriptions and references of comparative populations are listed in Supplementary Table S2.