But 'Steppe DNA' is itself a loose, imprecise term:It had to be some slip up like that. Everyone knows, certainly academics, that the Beakers were 50-60% Late Neolithic farmer like. Yes, the replacement figure in Britain was 90%, but that means 10% British Neolithic and 90% Beaker, or, as you say, steppe admixed.
It's loose, imprecise talk like this that gets the archaeologists' hackles up. The geneticists know what they mean, but they can confuse people who haven't read all the papers.
1. The Steppe is a vast area of land, several thousand miles long, with a wide variety of DNA across it; there is no DNA profile that encompasses all of it.
2. It is also vaguely defined in terms of being combination of other types of DNA, and has no clear unique identity of its own.
3. The combination that is identified as Steppe DNA was already present in Georgia, Armenia and Anatolia before it turned up in the Steppe.
4. 'Steppe DNA' misleadingly implies to the layman that its bearer migrated from the Steppe, when in practice his ancestors might have lived away from the Steppe for thousands of years, or not at all - having independently acquired a similar combination of DNA components from elsewhere.
The predominant component of Steppe DNA (EHG) was also already present in North Western Europe, long before the arrival of Bell Beaker. When people say Steppe DNA arrived there, what they actually mean is that CHG (or, more accurately, Iranian) DNA arrived.
Bell Beaker would also be less misleadingly identified as East Central European DNA, as its core DNA combination almost certainly arose in the Balkans or Carpathians, and outside of the Steppe.