From the NYT science section:
A comprehensive new paper tested 273 ancient horse genomes to pinpoint when and where modern horses were domesticated.
By Sabrina Imbler
Oct. 20, 2021
For thousands of years, the grassy plains of Europe and Asia were home to a mosaic of genetically distinct horse lineages. But a single lineage galloped ahead to overtake and replace all the other wild horses.
… After collecting and sequencing 273 ancient horse genomes, a team of 162 authors concluded that modern horses were domesticated around 4,200 years ago in steppes around southern Russia, near where the Volga and Don rivers intersect.[…]Modern Domestic Horses Come From Sarmatian/Scythian Steppe In 2200 BC — VDARE