Ok, I am not supporting bestiality here. But, I just came to know about a Dogxim, a dog fox hybrid and I had known for a long time that horses and donkeys can breed (to produce a mule). So, I was just curious, can humans breed with any other animals closely related to us?
For most people, except sub Saharan Africans, we are also talking about our ancestors when talking about neanderthals. Most of those bones we see on museums are probably the great x grandfathers of many people walking past.
Obviously we have no idea what happened over huge parts of deep human pasts, Neanderthals were a sparse population to begin with, and absorbing their people into the rest of humanity just by fucking is certainly a solution