Okay, I have two things I want to understand better:
I can’t tell what the moving parts are in this “bestiality” resolution. The only time the question of Neanderthal interbreeding should pose a problem is if someone wants to set up de novo Adam/Eve and their Eden before Homo sapiens have emerged. YECs don’t appear to be disturbed, today, by Neanderthal genetics found in the sapiens genome. And so pushing the de novo creation back in times progressively further and further shouldn’t change this ambivalence at all. As long as there are Homo sapiens present in the evolved pipeline, then de novo Adam and Eve (made to the same design specifications) are going to be Homo sapiens too (whether or not God wants to throw a few Neanderhtal fragments for the amusement of it.
So, I think the whole thing is a non-issue. I can’t imagine any YEC deciding that he loves Old Earth so much (all of a sudden) that he wants to move Adam and Eve into the 800,000 year timeline. Does this understanding differ from anyone else’s understanding?
And now for the second question: what does Mark mean here? What element is it in the traditional “de novo” scenario that doesn’t get cleared up? @anon46279830, can you reduce the answer to just a sentence or two?