European steppe groups may have been be implicated in the dispersal of ANE ancestry across Europe where it is currently pervasive.
The mtDNA composition of the steppe population is primarily West Eurasian, in contrast with northwest Russian samples of this period Der Sarkissian et al. PLoS Genetics 2013 where an East Eurasian presence is evident.
Samara experienced major population turnovers over time: early samples >6000 years belong primarily to mtDNA haplogroups U4 and U5, typical of European hunter-gatherers but later ones include haplogroups W, H, T, I, K, J.
via Razib Khan.