Nubian Complex reduction strategies in Dhofar, southern Oman (Usik et al. 2012)

From the paper:

If there was no Nubian Complex occupation in Egypt during the MIS 5de5b hiatus, from where did the Egyptian Late Nubian, dating no earlier than MIS 5a, come? Did it spread north from Sudan or was there an expansion of Arabian Nubian Complex toolmakers back into Africa? Certainly, the striking similarities between the Classic Dhofar Nubian and Egyptian Late Nubian, as compared with the Sudanese Late Nubian, might indicate such a scenario. Again, greater chronological resolution in African and Arabian Nubian assemblages is required to answer these questions.   

It seems overly simplistic to expect the expansion of Nubian Complex toolmakers into Arabia was a single migration or event; rather, it was more likely a process of recurring bidirectional movements across the Red Sea linked to consecutive phytogeographic range expansions and contractions. At the same time, the presence of technologically distinct, non-Nubian industries elsewhere in Arabia from MIS 5a to MIS 3 indicates separate, autochthonous culture groups and/or input from other adjacent regions (Marks, 2009; Armitage et al., 2011; Petraglia et al., 2011; Delagnes et al., 2012). In the case of the Wadi Surdud stratified assemblages in Yemen, dated tow60e40 ka BP (Delagnes et al., 2012), and Jebel Faya successive assemblages B and A, bracketed within MIS 3 (Armitage et al., 2011), both archaeological sequences are thought to be the products of local lithic traditions. Clearly, Late Pleistocene demography in Arabia was far more complex than one population emanating from a single source area.   

For now, it is clear that the Afro-Arabian Nubian Complex exhibits a robust archaeological signature on both sides of the Red Sea, in terms of site density, distribution, and long-term technological variability, always based on the core principal of opposed platform exploitation. This is likely the result of populations who were well and truly established in their respective regions for an extended period of time. Perhaps we have made too much of tracking routes of expansion and the timing of sea crossings into Arabia. The Red Sea may be more of a barrier for scholars today than it ever was for humans in the Middle Stone Age. 

Related comment (my emphasis):

Nubian technology has been found in association with a modern human child within occupation Phase 3 at the site of Taramsa 1 in Egypt. Science would suggest they're modern. Unless, of course, one is willing to propose an entirely new species that occupied NE Africa 100,000 years ago? 

Nubian technology has now been identified in central Arabia (article in press by Crassard and Hilbert) and seems to be spread across central and eastern Yemen as well. The Mudayyan Industry, published in Usik et al. 2012, falls sometime after the Nubian occupation of Dhofar and is clearly derived from Nubian Levallois technology. Moreover, this particular technology governed by bidirectional recurrent Levallois blank production is interpreted as the transition from Middle Palaeolithic Levallois to Upper Palaeolithic blade reduction as exemplified at Initial Upper Palaeolithic sites in the Levant such as Boker Tachtit and Ain Difla. Essentially, the Nubians in Arabia have provided the technological missing link for the MP-UP transition in the Levant. 

So, Nubians entered Arabia sometime between 130 - 100 ka and appear to have subsequently expanded northward during the early MIS 3 wet phase that would have facilitated north-south demographic exchange throughout the Peninsula. As for the Out of Arabia expansion eastward, this is still anyone's guess. We can be sure it wasn't related to Nubian Complex toolmakers.

Quaternary International doi:dx.doi.org/10.1016/j.quaint.2012.08.2111

Nubian Complex reduction strategies in Dhofar, southern Oman

Vitaly I. Usik et al.

Between 2010 and 2012, the Dhofar Archaeological Project has located and mapped 260 Nubian Complex occurrences across Dhofar, southern Oman. Many of these lithic assemblages are technologically homologous to the Late Nubian Industry found in Africa, while others may represent a local industry derived from classic Nubian Levallois technology. The purpose of this paper is to describe the various reduction strategies encountered at a sample of Nubian Complex sites from Dhofar, to explore inter-assemblage variability, and, ultimately, to begin to articulate technological units within the “Dhofar Nubian Tradition.” To achieve this aim, we have developed an analytical scheme with which to describe variability among Nubian Levallois reduction strategies. From our analysis, we are able to discern at least two distinct industries within a regional lithic tradition. Demographic implications of the enduring Dhofar Nubian Tradition are considered in light of new evidence found throughout the Arabian Peninsula.

Link

Pre-Neolithic dispersals into Arabia

The harsh climate of Arabia, periodically interrupted by more "green" periods has probably meant that the population living there has occasionally been driven out as climate deteriorated, with new populations moving in as climate improved. In more recent times, technological invention (e.g., the camel, the deep water well, or even more recently the discovery of oil) has allowed people to subsist in the desert a little more "comfortably."

One interesting question is whether the current Arabian population derives entirely from early Levantine Neolithic peoples, or also from people who had ventured there prior to it. A new paper in AJPA suggests that living Arabians are not entirely the descendants of Neolithic peoples, but also preserve signals of pre-Neolithic input from the Near East, by studying the mtDNA haplogroup R2 (see map on left for its current distribution).

From the paper:

It is noteworthy, however, that these pre-Neolithic sites do not bear any technological traits analogous to Terminal Pleistocene (Epipalaeolithic) assemblages found in the Near East. The only germane possibility of a connection between Arabia and the Near East during this period comes from the Faw Well site at the western edge of the Rub’ Al Khali (Edens, 2001). Although undated, the Faw Well lithic assemblage bears a close resemblance to the Late Ahmarian of the Levant (20–17 ka). Perhaps it was this, or a subsequent pulse from the Levant, that provided the demographic input expressed by the genetic lineages documented in this article.   

The results from the three analyzed southern Arabian clades do not support population continuity from the first occupants more than 50 ka ago (Fernandes et al., 2012) but do suggest some continuity across the Pleistocene- Holocene boundary. Our analysis indicates that the observed population expansion 13–12 ka is probably the result of genetic input from the Near East a few thousand years before the (debated) arrival of the PPNB culture in Arabia. If, however, there was a population expansion southward through Arabia some 13–12 ka, we have not yet found its archaeological signatures. Both regions exhibit stone tool technologies with some overlapping features, so it is warranted to suppose that we may one day locate a firm link between southern Arabia and the Near East sometime during the Late Pleistocene. Given the vast amount of unexplored territory in Arabia and paucity of archaeological sites with numerical ages, future investigations (both archaeogenetical and archaeological) throughout the Peninsula will undoubtedly serve to shed more light on this question. 

American Journal of Physical Anthropology DOI: 10.1002/ajpa.22131

Pleistocene-Holocene boundary in Southern Arabia from the perspective of human mtDNA variation

Abdulrahim Al-Abri et al.

It is now known that several population movements have taken place at different times throughout southern Arabian prehistory. One of the principal questions under debate is if the Early Holocene peopling of southern Arabia was mainly due to input from the Levant during the Pre-Pottery Neolithic B, to the expansion of an autochthonous population, or some combination of these demographic processes. Since previous genetic studies have not been able to include all parts of southern Arabia, we have helped fill this lacuna by collecting new population datasets from Oman (Dhofar) and Yemen (Al-Mahra and Bab el-Mandab). We identified several new haplotypes belonging to haplogroup R2 and generated its whole genome mtDNA tree with age estimates undertaken by different methods. R2, together with other considerably frequent southern Arabian mtDNA haplogroups (R0a, HV1, summing up more than 20% of the South Arabian gene pool) were used to infer the past effective population size through Bayesian skyline plots. These data indicate that the southern Arabian population underwent a large expansion already some 12 ka. A founder analysis of these haplogroups shows that this expansion is largely attributed to demographic input from the Near East. These results support thus the spread of a population coming from the north, but at a significantly earlier date than presently considered by archaeologists. Our data suggest that some of the mtDNA lineages found in southern Arabia have persisted in the region since the end of the Last Ice Age.

Link

The Nubian Complex in southern Arabia, 106 thousand years ago

I covered Jeffrey Rose's work most recently here. Together with his work on the Gulf Oasis, Jebel Faya, and the Skhul/Qafzeh hominids from the Levant, it now appears that modern humans were widely dispersed >100 thousand years ago in the Near East, possessing distinct lithic technologies. It is becoming increasingly impossible to reconcile this evidence with scenaria of Out-of-Africa after 70ka.

The pre-100ka Near East was seemingly teeming with modern humans; it may have been possible to dismiss these as the Out-of-Africa that failed when the Skhul/Qafzeh hominids were the only players in the game, but populations stretching from the Levant to southern Arabia did not simply vanish and were replaced after 70ka.

This leads to a conundrum:

• Either geneticists are in error when they date the L3/modern human expansion to 70 thousand years ago, or
• They are in error when they place its origin to Africa.

As I have argued before, the archaeological and genetic evidence can be reconciled if the L3/modern human expansion occurred recently Out-of-Arabia, during the super-arid conditions of MIS 4, after having establishing themselves there in the good times that preceded it.

From the paper:

The Nubian Complex is a regionally distinct Middle Stone Age (MSA) technocomplex first reported from the northern Sudan in the late 1960 s [1], [2]. Archaeological sites belonging to the Nubian Complex (Fig. 1) have since been found throughout the middle and lower Nile Valley [3]–[6], desert oases of the eastern Sahara [7], [8], and the Red Sea hills [9], [10]. Numerical ages from Nubian Complex sites (Table 1) are constrained within Marine Isotope Stage 5 (MIS 5), although temporal differences have been observed among assemblages; as such, it is divided into two phases, an early and a late Nubian Complex [5], [11].

I had previously speculated about the origin of modern humans in a wet Sahara, followed by their expansion into West Asia during MIS 5. I don't know how tenable this scenario is archaeologically, but it certainly appears to be chronologically and genetically: modern mankind coming to its own in the wet Sahara, collapsing demographically as the desert reasserted itself; finding a secondary cradle in Arabia, and expanding as the Arabian desert reasserted itself. Is this the solution: a tale of two deserts, pumping humans from Africa to the Near East pre-100ka and from the Near East to the rest of the world post-70ka?

From the paper:

The taxonomic identity of the Nubian Complex toolmakers is unknown, as no skeletal evidence has been discovered in association with any such assemblage. Although some archaic forms may have persisted in other parts of Africa at that time [79], the distribution of early anatomically modern human (AMH) remains suggest this species is the most likely candidate to have occupied northeast Africa during the Late Pleistocene. Cranial fragments of Homo sapiens found in the Omo river valley, Ethiopia (Fig. 1), represent the first appearance of AMH in East Africa ~195 ka [80]. Remains from Herto [81], Singa [82], and Mumba [83] in East Africa date to between ~160 and ~100 ka. Skeletal remains from Jebel Irhoud in Morocco show that an early form of Homo sapiens had expanded into North Africa as early as ~160 ka [84], and a modern human child discovered at Grotte des Contrebandiers in Morocco verifies the presence of AMH in North Africa by ~110 ka [85]. At the site of Taramsa Hill 1 in the lower Nile Valley, an AMH child dated to ~55 ka was found in association with a lithic industry (Taramsan) that is thought to have developed out of the late Nubian Complex [21], [86]. Despite the lack of direct evidence, given that AMH are the only species to have been found in North Africa from the late Middle Pleistocene onward, it is warranted to speculate that the Nubian Complex toolmakers were modern humans.

I have classified both Jebel Irhoud and Singa, as well as Omo II, and the Qafzeh/Skhul hominids as H. sapiens in my recent analysis of the Mounier et al. (2011) data. So, while it would be desirable to have osteological remains from the sites described in this paper, I'd say the odds are greatly in favor of them being modern humans.

Interestingly:

To some degree, the discovery of late Nubian Complex assemblages in Dhofar upholds this model. The distribution of this technocomplex in the middle and lower Nile Valley, the Horn of Africa, Yemen, and now Dhofar provides a trail of diagnostic artifacts - stone breadcrumbs - spread across the southern dispersal route out of Africa. The close similarity between African and Arabian late Nubian Complex assemblages suggests that these sites are more or less contemporaneous; they were separated for an insufficient amount of time for independently derived technological traits to develop between regions. As the late Nubian Complex at Aybut Al Auwal is dated to MIS 5c, slightly earlier than the late Nubian Complex in Africa [11], we remain open to the possibility that the late Nubian Complex originated in Arabia, and subsequently spread back into northeast Africa. Given the coarse chronological resolution in both Africa and Arabia (Table 1), however, the question of directionality cannot be adequately addressed, suffice to say there is cultural exchange across the Red Sea during MIS 5c.

Certainly the osteological evidence of modern humans in Africa (Omo and Irhoud, especially) predates that for the Near East. Also, some kind of Out-of-Africa must have taken place, since the Eurasian Y-chromosome and mtDNA phylogeny can be securely seen as a subset of the African phylogeny. Nonetheless, we don't really know when the Out-of-Africa even took place, and it could very well be that there was a first Into-Africa during MIS 5c.

Importantly:

Although southern Arabia experienced successive periods of extreme aridity after MIS 5, terrestrial archives document another increase in precipitation across the interior of Arabia during early MIS 3 [59], [104], enabling north-south demographic exchange between ~60–50 ka. South Arabian populations may have spread to the north at this time, taking with them a Nubian-derived Levallois technology based on elongated point production struck from bidirectional Levallois cores, which is notably the hallmark of the Middle-Upper Palaeolithic transition in the Levant [105], [106]. Further survey in central Arabia is required to test whether the Nubian Complex extends north of Dhofar. Until then, the fate of the Nubian Complex in Arabia must remain in question.

The puzzle is slowly filling up.

From ScienceNOW:

The problem with many of the stone tools found on the Arabian Peninsula, says New York University archaeologist Christian Tryon, is that they don't have much personality. "Stone tools are often unexciting things," he says, "like Paleolithic screwdrivers and hammers." None, he says, displayed signs of craftsmanship that could identify them definitively as the handiwork of African H. sapiens versus other hominids, such as Neandertals. None, that is, until archaeologist Jeffrey Rose of the University of Birmingham in the United Kingdom uncovered tools in Oman in 2010 with clear African connections. "This is the first time I've been convinced," says Tyron, who was not involved in the new work.

If modern humans were living in southern Arabia 106,000 years ago, the important question for human history is what happened next. Did they die out in Oman—another "failed expansion," as archaeologists describe it—or migrate north, going on to populate the globe? If the latter, it would challenge current genetic data placing global human migration out of Africa perhaps 80,000 years ago. Instead of "out of Africa," says Rose, "we could be looking at 'out of Arabia.' "

Indeed.

From the press release:

According to the authors, the evidence from Oman provides a "trail of stone breadcrumbs" left by early humans migrating across the Red Sea on their journey out of Africa. "After a decade of searching in southern Arabia for some clue that might help us understand early human expansion, at long last we've found the smoking gun of their exit from Africa," says Rose. "What makes this so exciting," he adds, "is that the answer is a scenario almost never considered."

These new findings challenge long-held assumptions about the timing and route of early human expansion out of Africa. Using a technique called Optically Stimulated Luminescence (OSL) to date one of the sites in Oman, researchers have determined that Nubian MSA toolmakers had entered Arabia by 106,000 years ago, if not earlier. This date is considerably older than geneticists have put forth for the modern human exodus from Africa, who estimate the dispersal of our species occurred between 70,000 and 40,000 years ago.

Even more surprising, all of the Nubian MSA sites were found far inland, contrary to the currently accepted theory that envisions early human groups moving along the coast of southern Arabia. "Here we have an example of the disconnect between theoretical models versus real evidence on the ground," says co-author Professor Emeritus Anthony Marks of Southern Methodist University. "The coastal expansion hypothesis looks reasonable on paper, but there is simply no archaeological evidence to back it up. Genetics predict an expansion out of Africa after 70,000 thousand years ago, yet we've seen three separate discoveries published this year with evidence for humans in Arabia thousands, if not tens of thousands of years prior to this date."

PLoS ONE 6(11): e28239. doi:10.1371/journal.pone.0028239

The Nubian Complex of Dhofar, Oman: An African Middle Stone Age Industry in Southern Arabia

Jeffrey I. Rose et al.

Despite the numerous studies proposing early human population expansions from Africa into Arabia during the Late Pleistocene, no archaeological sites have yet been discovered in Arabia that resemble a specific African industry, which would indicate demographic exchange across the Red Sea. Here we report the discovery of a buried site and more than 100 new surface scatters in the Dhofar region of Oman belonging to a regionally-specific African lithic industry - the late Nubian Complex - known previously only from the northeast and Horn of Africa during Marine Isotope Stage 5, ~128,000 to 74,000 years ago. Two optically stimulated luminescence age estimates from the open-air site of Aybut Al Auwal in Oman place the Arabian Nubian Complex at ~106,000 years ago, providing archaeological evidence for the presence of a distinct northeast African Middle Stone Age technocomplex in southern Arabia sometime in the first half of Marine Isotope Stage 5.

Link

The "Upper Paleolithic" of South Arabia

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.

Related:

• New Light on Human Prehistory in the Arabo-Persian Gulf Oasis
• The Southern Route “Out of Africa”: Evidence for an Early Expansion of Modern Humans into Arabia
• Age of mtDNA haplogroup L3: about 70 thousand years
• Incredible Human Journey

Y chromosome population structure in Arabian peninsula

On the left, the MDS plot of genetic distances in studied populations and others from the literature. The haplotypes are available in free supplementary material (pdf). Someone ought to feed these to Whit Athey's haplogroup predictor to get estimates of the haplogroup composition of the Arabian populations.

Hum Hered 2009;68:45-54 (DOI: 10.1159/000210448)

Local Population Structure in Arabian Peninsula Revealed by Y-STR Diversity

Farida Alshamali et al.

Abstract

Genetic studies have been underway on Arabian Peninsula populations because of their pivotal geographic location for population migration and times of occurrence. To assist in better understanding population dynamics in this region, evidence is presented herein on local population structure in the Arabian Peninsula, based on Y-STR characterisation in four Arabian samples and its comparison in a broad geographical scale. Our results demonstrate that geography played an important role in shaping the genetic structure of the region around the Near-East. Populations are grouped regionally but none of these groups is significantly differentiated from others and all groups merge in the Near-East, in keeping with this important migration corridor for the human species. Focusing on the Arabian Peninsula, we show that Dubai and Oman share genetic affinities with other Near-Eastern populations, while Saudi Arabia and Yemen show a relative distinctive isolated background. Those two populations may have been kept relatively separated from migration routes, maybe due to their location in a desert area.

Link

Y chromosomes from the Gulf of Oman

European Journal of Human Genetics advance online publication 10 October 2007; doi: 10.1038/sj.ejhg.5201934

Y-chromosome diversity characterizes the Gulf of Oman

Alicia M Cadenas

Abstract

Arabia has served as a strategic crossroads for human disseminations, providing a natural connection between the distant populations of China and India in the east to the western civilizations along the Mediterranean. To explore this region's critical role in the migratory episodes leaving Africa to Eurasia and back, high-resolution Y-chromosome analysis of males from the United Arab Emirates (164), Qatar (72) and Yemen (62) was performed. The role of the Levant in the Neolithic dispersal of the E3b1-M35 sublineages is supported by the data, and the distribution and STR-based analyses of J1-M267 representatives points to their spread from the north, most likely during the Neolithic. With the exception of Yemen, southern Arabia, South Iran and South Pakistan display high diversity in their Y-haplogroup substructure possibly a result of gene flow along the coastal crescent-shaped corridor of the Gulf of Oman facilitating human dispersals. Elevated rates of consanguinity may have had an impact in Yemen and Qatar, which experience significant heterozygote deficiencies at various hypervariable autosomal STR loci.

Link