I've been waiting for some concrete DNA evidence about where modern horses came from since I interviewed Alan Outram three years ago and he hinted that it was soon to be published. He indicated that Sintashta horses might end up being more important than Yamnaya ones, and now that the new paper, to which he contributed, has finally been published, I can see why.

  The new paper (Librado et al 2021) doesn't make the findings very clear IMO (refers to Europe as West Eurasia and makes the false assumption that Corded Ware was descended from Yamnaya) but it does answer some important questions. I will summarise the findings in a clear TLDR bullet point list below:

Botai may have been first to corral horses for milking but they didn't ride them.

Yamnaya kept horses for milking too...