The first comment on the substack links to this article, from 2010, that basically refutes this theory and this book. https://blog.waikato.ac.nz/bioblog/2010/10/killer-neandertal...
Thanks for this, I didn't see the comment in the article. The minute I saw "horizontal slit eyes" I was pretty much done. There's literally no way to know if that was true, for that to be a claim in a proposed theory rightly discredits that theory. I can see them being hairy. But deducing from having larger eyes that they'd be nocturnal and therefore have horizontal slit eyes... And then there's the issue of the flat…
Heck, it would not get attempted due to ethical issues, but technically it might be even plausible to clone a neanderthal using a human surrogate mother, there has been some work in cross-species cloning.