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. 2018 May;2(5):800-809.
doi: 10.1038/s41559-018-0518-2. Epub 2018 Apr 9.

Homo Sapiens in Arabia by 85,000 Years Ago

Free PMC article

Homo Sapiens in Arabia by 85,000 Years Ago

Huw S Groucutt et al. Nat Ecol Evol. .
Free PMC article


Understanding the timing and character of the expansion of Homo sapiens out of Africa is critical for inferring the colonization and admixture processes that underpin global population history. It has been argued that dispersal out of Africa had an early phase, particularly ~130-90 thousand years ago (ka), that reached only the East Mediterranean Levant, and a later phase, ~60-50 ka, that extended across the diverse environments of Eurasia to Sahul. However, recent findings from East Asia and Sahul challenge this model. Here we show that H. sapiens was in the Arabian Peninsula before 85 ka. We describe the Al Wusta-1 (AW-1) intermediate phalanx from the site of Al Wusta in the Nefud desert, Saudi Arabia. AW-1 is the oldest directly dated fossil of our species outside Africa and the Levant. The palaeoenvironmental context of Al Wusta demonstrates that H. sapiens using Middle Palaeolithic stone tools dispersed into Arabia during a phase of increased precipitation driven by orbital forcing, in association with a primarily African fauna. A Bayesian model incorporating independent chronometric age estimates indicates a chronology for Al Wusta of ~95-86 ka, which we correlate with a humid episode in the later part of Marine Isotope Stage 5 known from various regional records. Al Wusta shows that early dispersals were more spatially and temporally extensive than previously thought. Early H. sapiens dispersals out of Africa were not limited to winter rainfall-fed Levantine Mediterranean woodlands immediately adjacent to Africa, but extended deep into the semi-arid grasslands of Arabia, facilitated by periods of enhanced monsoonal rainfall.

Conflict of interest statement

Author InformationThe authors declare no competing financial interests.


Figure 1
Figure 1. Al Wusta location, map of site and stratigraphy.
A: The location of Al Wusta and other key MIS 5 sites in the region; B: Al Wusta digital elevation model showing location of AW-1 phalanx, marl beds, lithics and vertebrate fossils, and the locations of the trenches and sections. The inset shows a satellite image of the site; C: Stratigraphic log of Al Wusta showing the sedimentology of the exposed carbonate beds, isotopic values, OSL ages for sand beds and U-series and ESR ages for AW-1 and WU-1601. Sands are shown in yellow: lower massive sands are aeolian (Unit 1), upper laminated sands are waterlain (Unit 3a) and have been locally winnowed to generate a coarse desert pavement (Unit 3b), lacustrine marls are shown (Unit 2) in grey (for full key and description see Supplementary Figures 13 and 14 and Supplementary Information 5). Section PD40 is shown as it contains the thickest sequence and is most representative of Al Wusta, chronometric age estimates (marked *) from the site are depicted in their relative stratigraphic position, see Supplementary Figure 14 for their absolute positions.
Figure 2
Figure 2. Photographs and micro-CT scans of Al Wusta-1 Homo sapiens phalanx.
A: photographs in (left column, top to bottom) distal, palmar and proximal views, and (middle row, left to right) lateral 1, dorsal and lateral 2 views. Micro-CT cross-sections (illustrated at 2x magnification) include B (54% from proximal end) and C (illustrating abnormal bone).
Figure 3
Figure 3. Scatterplot of the first two principal components (PC) scores of the geometric morphometric analysis of the Al Wusta-1 phalanx compared with a sample of primates, including hominins.
Non-human hominoids: lilac; Gorilla: circles, Pan: triangles. Cercopithecoids: red; Colobus: triangles, Mandrillus: squares, Papio: circles. Neanderthals: blue diamonds. H. sapiens: green; early H. sapiens: circles, Holocene H. sapiens: squares. Al Wusta-1: black star, circled in red.
Figure 4
Figure 4. Scatterplot of the first two principal component (PC) scores from the geometric morphometric analyses of AW-1 and sample of comparative hominin 2nd, 3rd, and 4th intermediate phalanges.
Wireframes show mean configuration warped to extremes of PC axes in dorsal (left), proximal (middle) and lateral (right) views. Convex hulls added post-hoc to aid visualisation.
Figure 5
Figure 5. Selected Al Wusta lithic artefacts.
A: argillaceous quartzite flake; B: quartz hammerstone; C: ferruginous quartzite Levallois flake; D: chert Levallois flake; E: Quartz recurrent centripetal Levallois core; F: quartzite preferential Levallois core with centripetal preparation and pointed preferential removal.
Figure 6
Figure 6. The chronological and climatic context of Al Wusta.
The Al Wusta lake phase falls chronologically at the end of the time-range of MIS 5 sites from the Mediterranean woodland of the Levant (~130-90 ka) and earlier than the late dispersal(s) (~60-50 ka) as posited in particular by genetic studies. The chronology of these dispersals and occupations correspond with periods of orbitally modulated humid phases in the eastern Mediterranean that are important intervals for human dispersals into Eurasia, and are also proposed to correspond with episodes of monsoon driven humidity in the Negev and Arabian desert. Environmental amelioration of the Saharo-Arabian belt, therefore, appears to be crucial for allowing occupation at key sites that document dispersal out of Africa. A: East Mediterranean speleothem δ18O record from Soreq and Pequin Caves; B: global δ18O record; C: Insolation at 30 degrees north, showing the temporal position of key sites relating to dispersal out of Africa,,,. The chronology for Al Wusta shows the phases defined by the Bayesian model at 2σ.

Comment in

  • Joining the dots.
    Henry DO. Henry DO. Nat Ecol Evol. 2018 May;2(5):767-768. doi: 10.1038/s41559-018-0539-x. Nat Ecol Evol. 2018. PMID: 29632355 No abstract available.

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