I came across this interesting book chapter on The "Upper Paleolithic" of South Arabia by Jeffrey Rose and Vitaly Usik. I first became aware of Dr. Rose's work in Southern Arabia when I watched the "Incredible Human Journey" (see Related links below) a couple of years ago. The conclusions of the chapter seem to mesh quite well with some of my recent thoughts about a possible Out-of-Arabia expansion of modern humans, posterior to the earlier Out-of-Africa.
The following figure is instructive:
Notice the super-aridity of MIS 4, circa 70ka BP. This would certainly be an awful time for anyone to move into Arabia. Conversely, if there were anatomically modern people living there prior to MIS 4, the onset of the super-arid phase during MIS 4 would be a great time to get out.
As I mention in my previous post on mtDNA haplogroup L3, I think that the major human expansion associated with haplogroup L3 and its M/N subclades originated in Arabia, and the super-arid MIS 4 phase looks about right for a bottleneck out of which the descendants of only a single woman, the L3 ur-mother would survive.
From the book chapter:
So, we are able to make a few general observations regarding the Upper Paleolithic found in the southern portions of the peninsula: (1) there are multiple phases of human occupation in South Arabia throughout the latter half of the Upper Pleistocene, (2) there are elements loosely related to the Levantine sequence, however, the South Arabian Upper Paleolithic probably belongs to a unique and locally-derived lithic tradition, (3) there do not appear to be any links with East Africa (with the exception of the Hargeisan) from MIS 4-onward, and (4) assemblages from southern and south-western Arabia are dominated by different laminar-based technologies between 75 and 8 ka.
The Hargeisan is interesting, because it is a possible link of an expansion from Arabia to Africa:
One potentially additional piece of evidence for this hypothesized Near Eastern/Arabian-derived human expansion is the anomalous Hargeisan Industry found in the Horn of Africa. Known from a small number of findspots around Hargeisa (Clark, 1954), Boosasso (Graziosi, 1954) and Midhishi Cave in the Golis Mountains of northern Somalia (Gresham, 1984; Brandt, 1986), the Hargeisan has been found overlying MSA material and beneath LSA occupation layers.
Of course, the political situation in Somalia may suggest that scientists won't be studying the Hargeisan anytime soon.
More from the book chapter:
From an archaeological perspective, Straus and Bar-Yosef (2001: 2) entertain the same possibility: “there is, however, no reason a priori to exclude the possibility that intercontinental contacts occurred on a two-way street, especially at Suez, via Sinai, or across the shallow Bab al Mandab, so close to that corridor to sub-Saharan Africa, the Nile.” Marks (2005) and Otte et al. (2007) envisage similar scenarios during the MP/UP transitions in the Near East and Zagros regions. Both scholars argue that the archaeological evidence from Eastern Europe and Western Asia indicate the expansion of European UP technologies radiated from these areas, rather than Africa, during early MIS 3. Echoing this proposition from a biological perspective, Schillaci (2008) proposes the spread of Levantine-derived peoples into Australasia between 60 and 40 ka based on fossil evidence and phylogenetic relationships between populations.
and:
We maintain that the evidence from Arabia indicates the post-MIS 4 human expansion did not originate in sub-Saharan Africa; rather, early modern humans have emerged from a geographic range encompassing areas of northeast Africa, Western Asia, Arabia, and South Asia. These populations would have been forced to contract into environmentally stable refugia around Arabia such as the Ur-Schatt River Valley, coastal oases, Yemeni Highlands, and/or the Dhofar Mountains during climatic downturns. As such, the fluctuating dynamic between landscape carrying capacity and population density may have been a critical mechanism driving early human dispersals from the region. Episodes of climate change caused large portions of the Arabian peninsula to become uninhabitable due to such calamities as the inundation of the emerged continental shelf and desertification throughout the interior. Given the potential importance of these once favorable, now uninhabitable zones, future investigations in and around Arabia should endeavor to explore the heart of the desert and bottom of the sea.
A late date such as 70 Ka is not what archaeology suggests, including what I have read or Rose.
ReplyDeleteA key reading may be Petraglia 2009 'Out of Africa...' (scribd link), specially important is fig. 4, where we can see two (known) periods of MP in South Asia: (1) c. 125-105 Ka and (2) c. 80-40 Ka (which has been identified as extremely close typologically to South African MSA).
We can also see a single Arabian MP bracket c. 90-70 Ka., which could well be at the origin of the Indian group or at least should be related.
We could therefore attribute the older Indian MP to some archaic humans (Hathnora?) and accept that our kind was since 90 Ka ago in Arabia and since 80 Ka ago in South Asia.
However Armitage 2011 found even older coastal sites in Arabia, c. 130 Ka, which could well be precursors of the first Indian MP.
I am somewhat inclined to think that the 90-80 Ka migration is the main OoA and that the older is at best a marginal secondary element or even totally sterile but I can't say for sure.
I have dealt with these matters here, here, here and here. I seriously think (based on archaeology) that 70 Ka is a too short chronology, more like 90 Ka (at least).
70ka is not the date of Out-of-Africa, it is the date of Out-of-Arabia. There were modern humans in the Near East long before 70ka, and long before 90ka.
ReplyDelete"the post-MIS 4 human expansion did not originate in sub-Saharan Africa; rather, early modern humans have emerged from a geographic range encompassing areas of northeast Africa, Western Asia, Arabia, and South Asia".
ReplyDeleteThat idea all but kills the great southern coastal migration across the bab al Mandab. Seems most likely that humans used the route 'especially at Suez, via Sinai'.
Some of the older Arabian finds are Mousterian (and hence argue for Neanderthal rather than AMH presence in Arabia in those periods) and the case for them being AMH prior to about 50kya (apart from 75kya-100kya in the Levant) are pretty weak.
ReplyDeleteI do agree that continental shelf and Persian Gulf underwater archaelogy in Arabia ought to be central to resolving the possibilities.
My instincts are with terryt, favoring a Sinai route over a bab al Mandab route. The amount of genetic diversity present implied by uniparental DNA types in Australia and Melanesia by 45kya, that is absent from Africa or only backmigrated there in relatively recent times suggests that there needed to be a "Eurasian Eden" somewhere for a long time before that expansion. Maybe its an Arabian oasis, maybe its in Iran, maybe its in South Asia. But, there needs to be time for mtDNA M and N to diversify, for Y-DNA F to diversify, for Neanderthal admixture to reach fixation, and so on. It may very well have been a couple of refugia with the eastern refuge population mixing with the western one, but not visa versa.
Maybe its an Arabian oasis, maybe its in Iran, maybe its in South Asia.
ReplyDeleteIran was heavily ancient human/ Neanderthal most of the time in question, and much of it inhabitable except for the brief periods when climate was also favorable almost anywhere in the region.
Clearly, the time from ~130,000 to ~110,000 ya would have seen a huge increase in population in N and NE Africa, presumably to the point of population pressure driving people elsewhere. We have the evidence in the Levant, so that's likely the path they took - but mostly relatively coastal after that. Whether we actually need a 2nd ooA at a later point is questionable.
I agree that the diversity we know of and the homogeneity of admixture point to a significant population size and duration before 50,000 ya. And if we take the Denisovan admixture differences and timing from the published papers at face value, then there was already a significant population pre-Toba in SE Asia.
The thing is, starting again from ~100,000 to exactly Toba, climate was reasonably warm and wet (low dust concentration). So we really only need to look for these isolated 'Edens' to bridge ~10,000 years, and only if the majority of humans didn't make it to the subcontinent before then. I think there were likely a number of habitable spots, and by at least 80,000 - 90,000 ya the population started to grow, first in India, and then in SE Asia.
After Toba, it took until ~55,000 ya for the climate to improve enough to make the routes East and North (but also within India) easily passable for migration, again.
So, what sometimes looks like two or more migrations, may just be the combination of that 10,000 year gap, the immediate Toba interruption and temporary separation of populations in Asia, and additional separation until climate improved ~55,000 ya.