Russian archaeologist Leo Klejn (2017) noted that in the Yamnaya
population, R1b-L23 is predominant, whereas Corded Ware males
belong mostly to R1a, as well as far-removed R1b clades not found in
Yamnaya. In his view, this does not support a Yamnaya origin for the
Corded Ware culture.[58] British archaeologist Barry Cunliffe describes
this inconsistency as "disconcerting for the model as a whole".[59] Klejn
has also suggested that the autosomal evidence does not support a
proposed Yamnaya migration, as Western Steppe Herder ancestry is
lesser in the area from which the Yamnaya were proposed to have
expanded, in both contemporary populations and Bronze Age
specimens.[60]
Furthermore, Balanovsy et al.[61] (2017) found that the majority of the
Yamnaya genomes studied by Haak and Mathieson belonged to the
"eastern" R-GG400 subclade of R1b-L23, which is not common in
western Europe, and none belonged to the "western" R1b-L51 branch.
The authors conclude that the Yamnaya could not have been an
important source of modern western European male haplogroups.
An analysis by David Anthony (2019) suggested a genetic origin of
Proto-Indo-Europeans (associated with the Yamnaya culture) in the
Eastern European steppe north of the Caucasus, deriving from a
mixture of Eastern European hunter-gatherers (EHG) and hunter-
gatherers from the Caucasus (CHG). Anthony also suggested that the
Proto-Indo-European language formed mainly from a base of languages
spoken by Eastern European hunter-gathers with influences from
languages of northern Caucasus hunter-gatherers, in addition to a
possible later and more minor influence from the language of
the Maykop culture to the south (which is hypothesized to have
belonged to the North Caucasian languages) in the later Neolithic or
Bronze Age, involving little genetic impact.[31]