Re: "I have no problem with the idea of multiple emigrations out of Africa. There just doesn't seem to be evidence of interbreeding with Neandertals." from -soilguy (I think?)

Anyway, I haven't looked at the links yet but do any of them refer to how all the populations that left Africa before 70,000 yr. ago were probably wiped out by the big volcano back then. Was it Tambura, in Indonesia? I'll go check the web, but there was a sort of "nuclear winter" back then which would explain why our diversity mainly traces back 70,000, except within Africa. Neanderthals probably did survive, being far enough away and better adapted. Basically, they could easily be the only 'out of Africa' group, from our lineage, that survived the volcano.
Pyrolysis creates reduced carbon! ...Time for the next step in our evolutionary symbiosis with fire.