[PatrickHenry]

I can see interbreeding with Neanderthals, but not with Homo erecti based on this slight evidence.

But once you've had a taste of non-Sapiens, there's no place to draw the line. In for a dime ...

[AntiGuv]

Good point! However, the Neanderthals were much more closely related to Homo sapiens than were Homo erectus, and it seems more likely that they could've exchanged genes without leaving much of an imprint. To quote wikipedia:

It is generally accepted that both Neanderthals and Homo sapiens evolved from earlier "archaic" Homo sapiens, but the classification of Neanderthals depends on when in the timeline these modern humans are considered a separate species from the "archaic" forms.

So, it may in theory be the case that they were similar enough from a genomic standpoint that we haven't been able to distinguish the admixture. But more likely not! I'm quite skeptical of the idea myself. If so, where did all the distinctive Neanderthal features go? Stated differently, how could all the progeny bear such a remarkably indistinguishable resemblance to other Homo sapiens?

And the differences between Homo erectus and Homo sapiens makes the differences with Neanderthal seem downright trivial. Brain capacity alone: Homo erectus had 75% that of Homo sapiens. So, if they mated, where did all the retard hybrids go?? :)

[AntiGuv]

Check out the difference between a Neanderthal skull and a modern human skull; and this is trivial compared to a Homo erectus!

[SunkenCiv]

But once you've had a taste of non-Sapiens, there's no place to draw the line.

Well put.

The Neandertal Enigma
by James Shreeve

Frayer's own reading of the record reveals a number of overlooked traits that clearly and specifically link the Neandertals to the Cro-Magnons. One such trait is the shape of the opening of the nerve canal in the lower jaw, a spot where dentists often give a pain-blocking injection. In many Neandertal, the upper portion of the opening is covered by a broad bony ridge, a curious feature also carried by a significant number of Cro-Magnons. But none of the alleged 'ancestors of us all' fossils from Africa have it, and it is extremely rare in modern people outside Europe." [pp 126-127]