Arabia is a very interesting case for a variety of reasons: It has to be implicated one way or another in the tale of human origins and dispersals: it lies in the natural route Out-of-Africa, and in the intermediate space between the early modern human remains from Ethiopia, the later modern humans from the Levant, as well as the disputed late Neandertals of West Asia.
Unfortunately, current climatic conditions, as well as past episodes desiccation have resulted in substantial population; if anyone wanted to find out what the people who lived there during the Middle Paleolithic were like, he will find little continuity between them and the current inhabitants. The lack of genetic evidence is, unfortunately also accompanied by a general lack of anthropological evidence. Industries with links to Africa or the Levant are devoid of associated remains. But, the paper produces a hopeful note:
Yet, recent support for an MIS 5 expansion of Homo sapiens comes from archaeological finds of characteristic Middle Palaeolithic technologies in Arabia in MIS 5e–c – and nuclear genomic estimates which indicate that the split between Africans and non-Africans occurred as early as 130 to 90 ka , consistent with fossil finds of Homo sapiens in the Levant ,  and at the time of possible interbreeding of Homo sapiens and Neanderthals . These controversies indicate the need to recover hominin fossils in Arabia, which is feasible given the identification of Pleistocene mammalian fauna in a nearby lake basin of the Nefud , .
Tabun is associated with Neandertals, although that attribution, like most everything in palaeoanthropology is controversial.So, it might be possible that the Jubbah was occupied by Neandertals too, and this might make this population a prime candidate for the signal of Neandertal admixture carried by non-Africans.
At present, there seem to be two candidates for the modern human Out-of-Africa: Skhul (Levant; linked to Northwest Africa here) and the Nubian technocomplex of (south Arabia; linked to Northeast Africa). I don't have a clear picture of how it may have all played out; it would certainly be wonderful if it were possible to extract DNA from, say, Skhul/Qafzeh modern humans or the Levantine Neandertals, because that would definitely show how (i) the former may either be related to later Eurasians, or may be a failed experiment as hitherto supposed, and (ii) the latter might be a source of Neandertal DNA in non-Africans, or indeed something much closer to modern humans as their morphological intermediacy might suggest.
PLoS ONE 7(11): e49840. doi:10.1371/journal.pone.0049840
Hominin Dispersal into the Nefud Desert and Middle Palaeolithic Settlement along the Jubbah Palaeolake, Northern Arabia
Michael D. Petraglia et al.
The Arabian Peninsula is a key region for understanding hominin dispersals and the effect of climate change on prehistoric demography, although little information on these topics is presently available owing to the poor preservation of archaeological sites in this desert environment. Here, we describe the discovery of three stratified and buried archaeological sites in the Nefud Desert, which includes the oldest dated occupation for the region. The stone tool assemblages are identified as a Middle Palaeolithic industry that includes Levallois manufacturing methods and the production of tools on flakes. Hominin occupations correspond with humid periods, particularly Marine Isotope Stages 7 and 5 of the Late Pleistocene. The Middle Palaeolithic occupations were situated along the Jubbah palaeolake-shores, in a grassland setting with some trees. Populations procured different raw materials across the lake region to manufacture stone tools, using the implements to process plants and animals. To reach the Jubbah palaeolake, Middle Palaeolithic populations travelled into the ameliorated Nefud Desert interior, possibly gaining access from multiple directions, either using routes from the north and west (the Levant and the Sinai), the north (the Mesopotamian plains and the Euphrates basin), or the east (the Persian Gulf). The Jubbah stone tool assemblages have their own suite of technological characters, but have types reminiscent of both African Middle Stone Age and Levantine Middle Palaeolithic industries. Comparative inter-regional analysis of core technology indicates morphological similarities with the Levantine Tabun C assemblage, associated with human fossils controversially identified as either Neanderthals or Homo sapiens.