Iosif Lazaridis, David Reich, Failure to Replicate a Genetic Signal for Sex Bias in the Steppe Migration into Central Europe, March 14, 2017
Goldberg et al., Familial migration of the Neolithic contrasts massive male migration during Bronze Age in Europe inferred from ancient X chromosomes, September 30, 2016
Were Bronze age Central Europeans the product of unions between Foreign Pastoral Men from the Eurasian Steppe and Native Farmer Women from Central/Eastern Europe? One study (Goldberg et al. 2016) says they were and the other says they weren't.
To determine if admixture between Steppe Pastrolites and European farmers was sex bias both studies estimated Steppe Pastrolite ancestry and European farmer ancestry in the X chromosome and autosomal chromosome of Bronze age Central Europeans.
But each used different methods to do so. Goldberg et al. 2016 used ADMIXTURE and the other used qpAdm. In my opinion qpAdm is a better method than ADMIXTURE. So although I'm undecided, if I had to guess I'd guess that Lazardis and Reich are correct.
Let's look at the mtDNA of Bronze age Central Europeans to see if there's any evidence of sex bias admixture.
Corded Ware. N=67.
mtDNA: Steppe 42% (28), Farmer 41% (27), Unknown 17% (12)
Y DNA: 100% Steppe.
Autosomal: ~75% Steppe, ~25% Farmer
Bell Beaker. N=42.
Steppe=38% (16), Farmer=36% (16), Unknown 26% (10)
Y DNA: 100% Steppe
Autosomal: ~50% Steppe, ~50% Farmer
Steppe=36% (34), Farmer=28% (26), Unknown 36% (34)
Y DNA: 100% Farmer?(yHG I2, could be Steppe aswell)
Autosomal: ~60% Steppe, ~40% Farmer.
Keep in mind I counted originally hunter gatherer "WHG" mHG U5b as farmer. mtDNA data doesn't suggest admixture between Steppe Pastrolites and Native Central/East European farmers was sex bias except maybe in Corded Ware. At least 40% of Corded Ware mtDNA is of farmer origin but only 25% of their ancestry is.
mtDNA from modern Europeans in my opinion though does indicate sex bias admixture has occurred in European history. Specifically it indicates most of modern European mtDNA is "EEF" and "CHG", from the Neolithic Near East.
Is my mtDNA Farmer or Steppe?: If you want to know your mtDNA is of Eurasian Steppe Pastrolite or European Farmer origin email me your haplogroup to firstname.lastname@example.org. Most European mtDNA can be labelled as Steppe or Farmer. For example I know my mtDNA (U5b2a2) is from European hunter gatherers who were assimilated by farmers and my Y DNA (R1b) is of Steppe origin.