Kivisild et al. (2003) have proposed either South or West Asia,
[11][note 2] while Mirabal et al. (2009) see support for both South and Central Asia.
[9]
South Asian populations have the highest
STR diversity within R1a1a,
[37][38][9][3][1][39] and subsequent older
TMRCA datings, and R1a1a is present among both higher (Brahmin) castes and lower castes, although the presence is substantially higher among Brahmin castes.
[1][39] From these findings some researchers have concluded that R1a1a originated in South Asia,
[38][1][note 11] excluding a substantial genetic influx from Indo-European migrants.
[38][37][3]
However, this diversity, and the subsequent older TMRCA-datings, can also be explained by the historically high population numbers, which increases the likelihood of diversification and
microsatellite variation.
[41][42] According to Sengupta et al. (2006), "[R1a1 and R2] could have actually arrived in southern India from a
southwestern Asian source region multiple times."
[37][note 12] Silva et al. (2017) noted that R1a in South Asia most "likely spread from a single
Central Asian source pool, there do seem to be at least three and probably more R1a founder clades within the
Subcontinent, consistent with multiple waves of arrival."
[42]
