The virtual absence of Z283 subclades, namely Z280 and M458, and the total representation of R1a1a-derived samples by the Z93 marker in our dataset support an earlier observation that the M198 chromosome likely differentiated in the region between Eastern Europe and South Asia (Pamjav et al., 2012), and subsequently expanded in opposite directions. However, it will require additional R1a1a* samples from different populations across Eurasia to comprehensively evaluate the geographic origins, distribution and ethno-linguistic associations of the individual M198-derived lineages (Pamjav et al., 2012).

Another haplogroup that is associated with the spread of agriculture from the Fertile Crescent and Anatolia regions is J2-M172 (Cinnioğlu et al., 2004 and Semino et al., 2004). According to Sahoo et al. (2006), only J2 lineages, originating from West Asia rather than Central Asia, represent an external contribution to the Indian paternal gene pool. In particular, subclade J2a-M410 is believed to have entered through the northwestern corridor and subsequently diffused to the south and east (Sahoo et al., 2006 and Thangaraj et al., 2010). This haplogroup is present exclusively in the Lingayat (6.93%), except for one individual from Vokkaliga, suggesting gene flow from West Asia (Sahoo et al., 2006 and Thangaraj et al., 2010). Interestingly, four J2b2-M241 Lingayat males displayed a null allele at DYS458 and failed to produce the AMGY PCR amplicon while their X homolog (AMGX) amplified successfully. Comparison of Y-STR haplotypes of the affected males from the present study with those from the literature (Cadenas et al., 2006), demonstrated a high level of allele sharing, implying shared paternal lineages or a recent common ancestry for these groups of individuals.

From the paper:This study extends the results of Pamjav et al. 2012 which found only Z93 within R1a1 in mainland Indian populations. The authors estimate 12.8ky as the age of R-Z93 in the Lingayat, but since this uses the evolutionary mutation rate it should actually be divided by a factor of 3.6 which translates into ~1,500BC. So, it seems quite likely that R-Z93 moved from Central->South Asia during the Bronze Age, both on account of its age and the fact that it is a subset of Central Asian diversity. Haplogroup R2 with a nominal age of ~22ky in the Lingayat seems more like a Neolithic lineage.Also of interest:According to the paper the Lingayat are a community that originally attracted members from across the caste system, while the Vokkaliga are involved in farming. An uneven distribution of haplogroup J2a has been previously observed, so I guess this paper adds to this evidence.Available online 7 May 2013Shilpa Chennakrishnaiah et al.Previous studies have shown that India's vast coastal rim played an important role in the dispersal of modern humans out of Africa but the Karnataka state, which is located on the southwest coast of India, remains poorly characterized genetically. In the present study, two Dravidian populations, namely Lingayat (N = 101) and Vokkaliga (N = 102), who represent the two major communities of the Karnataka state, were examined using high-resolution analyses of Y-chromosome single nucleotide polymorphisms (Y-SNPs) and seventeen short tandem repeat (Y-STR) loci. Our results revealed that the majority of the Lingayat and Vokkaliga paternal gene pools are composed of four Y-chromosomal haplogroups (H, L, F* and R2) that are frequent in the Indian subcontinent. The high level of L1-M76 chromosomes in the Vokkaligas suggests an agricultural expansion in the region, while the predominance of R1a1a1b2-Z93 and J2a-M410 lineages in the Lingayat indicates gene flow from neighboring south Indian populations and West Asia, respectively. Lingayat (0.9981) also exhibits a relatively high haplotype diversity compared to Vokkaliga (0.9901), supporting the historical record that the Lingayat originated from multiple source populations. In addition, we detected ancient lineages such as F*-M213, H*-M69 and C*-M216 that may be indicative of genetic signatures of the earliest settlers who reached India after their migration out of Africa.