Most frequent among these are R1a1 and R2a, which are associated with Indo-European peoples and the Bronze Age migration into South Asia c. 3000 BC, and probably originated in either South Asia,[20][21] [22][23][24][25] Central Asia[26][27] or Iran and Caucasus.[28][29] R2a, unlike its extremely rare parent R2, R1a1 and other clades of haplogroup R, is now virtually restricted to South Asia. Two other typically South Asian lineages, haplogroup H1 and haplogroup L3 (defined by SNP mutation M20) have also been observed from few samples.[30][27]