An early expansion through India seems a necessary assumption for the out of Africa hypothesis to stand. But where’s the evidence? For example I was just looking at Wikipedia:

http://en.wikipedia.org/wiki/Haplogroup_C_(Y-DNA)

From the article: “It represents a great coastal migration along Southern Asia, into Southeast Asia and Australia, and up the Asian coast.” Note, no ‘maybes’ or ‘possiblys’. But when we read more closely: “Haplogroup C5 occurs at a very low frequency in India, Nepal, and Pakistan.” Note, not in southern tribal groups which is what we’d expect if C5 was an early arrival and SE Asian types derived from types who had moved through India. Also: “Haplogroup C3-M217 is probably the most important of these, as the geographic extent of its dispersal is without compare”. Across the northern latitudes from Germany to North America. Now isn’t that what we’d expect if Y-chromosome C had moved through Central Asia?

I’ve said before that many people seem to have an emotional need to accept a single point of origin for all species.

I realise that Xylophones tend to be most common in West Africa. That has occurred to me in the past.

“I’ve been meaning to mention that I too have noticed surprising similarities between some SE Asian Music and some African. But we have to remember that Madagascar was settled by what we today would call Indonesians. Presumably they reached the African mainland and took their music and instruments, especially xylophone types.”

Thanks for raising that very interesting point. You might be familiar with the work of A. M. Jones, who did very detailed comparative studies of African and Indonesian xylophones, finding several remarkable points of similarity. He too postulated an influence from Indonesia through Madagascar to Africa. The problem with this theory is that it is not borne out by the distribution of xylphones in Africa, which are, I believe, more common in the West than the East — and not common in Madagascar itself.

A more recent and more convincing interpretation (as offered by, among others, Roger Blench) is that the commonalities could be due to the presence of African slaves in Southeast Asia and/or Indonesia at some point in the distant past. The xylphone could have diffused in this area in a manner very similar to the way the marimba became so popular in Latin America as a result of the influx of African slaves in the colonial era.

While I have found strong evidence of an “African signature” in SE Asia and Indonesia and Melanesia dating possibly to the “Out of Africa” migration, I see no evidence that xylophones were part of that very early development.

The Out of Africa evidence is very real and very convincing, not at all the product of wishful thinking. Whether all homo sapiens derive from a single “Adam and Eve”-like pair is highly debatable, agreed. But the mtDNA of everyone tested so far has pointed quite clearly to a single female progenitor, in Africa. She was not the only “modern” human alive at that time, but she was, apparently, the only female whose lineage has survived to the present day. The evidence for her existence is very strong.

I agree various groups of humans have been through several bottlenecks. But not necessarily the whole human population at once. However I would argue that many people have an emotional desire to believe we all come from just one small group. After all two thousand years of Western history has been based on the idea.

I’ve been meaning to mention that I too have noticed surprising similarities between some SE Asian Music and some African. But we have to remember that Madagascar was settled by what we today would call Indonesians. Presumably they reached the African mainland and took their music and instruments, especially xylophone types.

In the Out of Africa case, it seems to me that the problem you’re considering would be relevant if the original OOA migrants were all from the same family. If several different families were involved, then the dangers of inbreeding would be greatly reduced, no? The same would be the case with population bottlenecks I would think.

IMO, Out-of-Africa should really be called: Out of Africa with Bottleneck(s). That’s what makes Oppenheimer’s thinking on all this so convincing — he takes the bottleneck issue very seriously, whereas many others gloss over it. There ARE significant differences that need to be taken into account in any version of OOA. In other words, for OOA to have real explanatory value, it would seem that some sort of major bottleneck, via either Toba or a Tsunami, perhaps, is almost a necessity for OOA to work.

As far as the differences between mtDNA and Y lines, I don’t see your point. Both lines take us back to Africa but neither supports the survival of the earliest Out of Africa migration, into the Levant. I don’t understand the technicalities well enough to explain why, but I don’t know of many geneticists who believe that line survived.

http://remotecentral.blogspot.com/2007/11/human-evolution-on-trial-hybrid-vigour.html

You may like to comment. There is also the problem that Y-chromosome and mitochondrial DNA evidence doesn’t support that migration route either. Australian Aborigine and Indian lines are very different. Sure, it’s possible to argue any original Indian lines died out. But it’s my understanding the modern humans reached Sri Lanka long after they’d crossed Wallaces line to reach Australia and New Guinea. Doesn’t fit the pattern shown in the link.

The link also says the first modern humans out of Africa became extinct. In fact mtDNA evidence can be interpreted as indicating they didn’t. Human mtDNA lines are much older than Y-chromosome lines.

All this of course has very little to do with America.

My own specialty is music and I can tell you there are huge differences between America north of Mexico, where, with only a few exceptions, you have essentially three instrument types, the membranophone, the rattle and the flute. In Central and South America there are far more different instrument types, not only among the more “advanced” cultures, but even among hunter-gatherers or simple horticulturalists. And here too the resemblances to Melanesia are striking, including the use of pipes, both panpipes and free pipes and also trumpets. All these instruments are played in ensembles using a technique common in Africa, SE Asia, Indonesia and Melanesia (but almost absent in N. America) called “hocketing,” and they are very often divided into male-female pairs, as in Africa, SE Asia, Indonesia, China and Melanesia.

I’m not suggesting trans-Pacific migrations, there is no evidence of that at all. But there IS good evidence for a very early migration beginning in SE Asia and continuing along the East coast of Asia to the coast of Beringia and then down the West coast of the Americas. This would have been an extension of the original coastal Out of Africa migration. The most logical explanation of the total American picture is the one offered by Steven Oppenheimer in his book “The Real Eve.” For a summary, you can check his interactive map, the “Journey of Mankind”: http://www.bradshawfoundation.com/journey/

The cranial morphology of certain South American Paleoamerindian samples resembles Australesians more than certain North American samples. Why? The authors of these studies (Neves et al) still favor the Beringial multi-migration hypothesis, with a rapid initial migration to South American accounting for such similarities and a later migration accounting for the derived morphology. This is perhaps where ancientDNA might shed some light? But otherwise, let’s be careful in completely dismissing the possibility of trans-oceanic genetic contributions to South American populations. It may not be the case for extant populations, but for extinct ones for which we have skeletal remains? The great majority of the evidence points to the former beringial scienario, but we still have gaps nonetheless.