Forest_Dump wrote:Well, I am not sure the multi-regional model is still held by many and the "out of Africa" model does not preclude some interbreeding between "recent" H.s. migrants and resident descendants of even the earliest migrations out. In fact, it seems there is good DNA evidence that anatomically modern Homo sapiens did interbreed with the Neanderthals in Europe so why not other descendant populations throughout Asia, etc?
Thanks for responding. It's been ages (during the '70s) since I took the time to make anthropology a study. At that time there was still much talk about the so-called "missing link" and anthropology's response to it. In any case, I'm reading the massive A.P. biology text book as a way of catching up, recognizing of course I'll never get to the leading edge. I confess I've gained a great deal of respect for the text even if it isn't up-to-date and might be misleading in places. Note that though the text (6th ed.), by Neils Campbell (UC Riverside) and Jane Reece (Palo Alto) a publishing specialist, doesn't often refer to the individual contributors and large number of reviewers within the text, it does acknowledge their value. The evolutionary biologist Mark Ridley of Oxford is identified as the main contributor to the chapter which presents the ideas I relayed.
With respect to the status of the hypotheses, the intent of my post was merely to draw a sharper contrast in ways of thinking about the evolution of homo sapiens than might not be evident without it. What I found interesting in these two hypotheses is how they are similar to the difficulty of figuring out origins in general. The DNA (and RNA) analysis, coupled with cladistics has pretty much become the method of choice. Prior to there being some consensus reached, it seems as if two possible ways of thinking about the origin of species (or of life, or of some branch in the tree of life) is to adopt either a monophyletic orientation or a consolidation of mixing. In the deepest branches, it seems that consensus is now moving toward the absence of a single common ancestor to the three domains of Bacteria, Archaea and Eucharyotes", favoring a "ancestral community of primitive cells that swapped DNA promiscuously." However, once these domains developed, the consensus tends toward it being monophyletic, such that a single branch node occurs for each new phylum. As the branch comes to be more recent, however, having less of a evolutionary past, it becomes more difficult to determine origins because, perhaps, there is more evidence that clouds it.
James