prehistoric wi

First off I wasn't sure if this would count as an ASB given Toba almost drove us to extinction but if it is do move it to that section of the forum. Anyways as you all may know 75,000 years ago humans actually came rather close to becoming extinct as a great catastrophe from Lake Toba occurred...

For the sake of a focused discussion of the PoD, please accept the following (in part controversial) premises as given IOTL (and maybe necessary background information for the what-if): 1.) The Eurasian steppe horse was domesticated for the first time somewhere between the Dnieper and Volga...