http://en.wikipedia.org/wiki/Multiregional_origin_of_modern_humans states
that " The hypothesis holds that humans first arose near the beginning of
the Pleistocene two million years ago and subsequent human evolution has
been within a single, continuous human species. This species encompasses
archaic human forms such as Homo erectus and Neanderthals as well as modern
forms, and evolved worldwide to the diverse populations of modern Homo
sapiens sapiens. The theory contends that humans evolve through a
combination of adaptation within various regions of the world and gene flow
between those regions. Proponents of multiregional origin point to fossil
and genomic data and continuity of archaeological cultures as support for
their hypothesis."

Further, one of the papers you cited,
http://www.ts-si.org/biology/30943-modern-humans-interbred-with-archaic-homi
nids-before-leaving-africa states, in part:
      "The modern humans species, Homo sapiens, interbred with more archaic
forms in their ancestral African home before spreading throughout the
world."
The authors mention Neanderthals several times as one of the lines that
interbred with humans within Africa. 

http://www.sciencedaily.com/releases/2012/08/120813155521.htm explains the
1-4% of Neanderthal genes in modern humans as genetic remnants arising out
of our common ancestry with Neanderthals.   

I'm out of my depth on this stuff, but it certainly appears that the Recent
Out of Africa hypothesis is compatible with modern humans interbreeding with
Neanderthals while still in Africa and their issue then leaving Africa to
populate the rest of the world. Whether or not my interpretation is
accurate, I am skeptical that any branch of hominids uniformly refused to
interbreed with members of other branches. Maybe there was enough genetic
difference that such mating was sterile, similar to the issue of horses and
donkeys. ?????

I wouldn't be surprised to learn that modern humans have more archaic
hominid DNA either.    


best wishes, 
Ron


 >One of the two main points of the Out of Africa hypothesis has always has
been that there was absolutely no interbreeding ever between modern humans
and other hominids, whether in Africa or elsewhere, and that modern man was
supposedly a wholly separate species. So, since this has been debunked, it
makes the Out of Africa theory even less likely than before. There's now
some scientists claiming that the various hominids all over the world got
gradually hominised gradually via evolution/gene-transfer between
populations etc., with Neanderthals eventually evolving more modern  traits
etc., rather than a mass influx of modern humans from Africa in very recent
times.

Oh, and there was also mention of intermixture between modern man and
archaic hominids in Africa, not just Neanderthals and Denisovans. Given the
sheer lack of fossils found so far, it wouldn't surprise me if advancing
technology >eventually shows that modern humans have a far bigger percentage
of archaic hominid DNA  than currently discovered.

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