the steppe ancestry is ~20-30% in pakistan/punjab. 30% in brahmins in north india. 20% in brahmins in south india.
In gangetic plain goes from 20 to 10% in peasants as u go west to east (10% in bengal).
In south india it’s like 5% among non-brahmins.
~0% in dalits in the south and some tribals. in north india lower than 10% in dalits like chamars.
it correlates with skin color, but imperfect, since skin color is due to only a few genes and sample variance is higher.
the high genetic diversity is because indian people are a mix of VERY DIFFERENT population groups, one related to those of europe and west asia, and one distantly related to the people of eastern eurasia and australia. these lineages were separated for ~50,000 years before mixing 5,000 years ago.
the fraction of onge increases as you go east, but there is still appreciable stepple. clearly the aryans were outrunning the core post-IVC zones, and were marginally mixed with IVC. eg. bihar brahmins have way more onge than sindhis, but also 50-100% more steppe.
Tribal R1a penetration
There is R1a penetration among tribals. the great exception here are todas. look at munda. almost no steppe or r1a. dravidian tribals have both to some extent. the munda are a counter-culture to the aryan-steppe patrlineage conquest system. they either resisted successfully or were exterminated. read their myths. they’re alien to India. the irony of calling them indigenous is they are profoundly other. 100% austroasiatic men, probably from the kra isthmus. evidence they used to occupy lowlands, driven up.