Chronology of Ksar Akil (Lebanon) and Implications for the Colonization of Europe by Anatomically Modern Humans

Abstract

The Out-of-Africa model holds that anatomically modern humans (AMH) evolved and dispersed from Africa into Asia, and later Europe. Palaeoanthropological evidence from the Near East assumes great importance, but AMH remains from the region are extremely scarce. ‘Egbert’, a now-lost AMH fossil from the key site of Ksar Akil (Lebanon) and ‘Ethelruda’, a recently re-discovered fragmentary maxilla from the same site, are two rare examples where human fossils are directly linked with early Upper Palaeolithic archaeological assemblages. Here we radiocarbon date the contexts from which Egbert and Ethelruda were recovered, as well as the levels above and below the findspots. In the absence of well-preserved organic materials, we primarily used marine shell beads, often regarded as indicative of behavioural modernity. Bayesian modelling allows for the construction of a chronostratigraphic framework for Ksar Akil, which supports several conclusions. The model-generated age estimates place Egbert between 40.8–39.2 ka cal BP (68.2% prob.) and Ethelruda between 42.4–41.7 ka cal BP (68.2% prob.). This indicates that Egbert is of an age comparable to that of the oldest directly-dated European AMH (Peştera cu Oase). Ethelruda is older, but on current estimates not older than the modern human teeth from Cavallo in Italy. The dating of the so-called “transitional” or Initial Upper Palaeolithic layers of the site may indicate that the passage from the Middle to Upper Palaeolithic at Ksar Akil, and possibly in the wider northern Levant, occurred later than previously estimated, casting some doubts on the assumed singular role of the region as a locus for human dispersals into Europe. Finally, tentative interpretations of the fossil's taxonomy, combined with the chronometric dating of Ethelruda's context, provides evidence that the transitional/IUP industries of Europe and the Levant, or at least some of them, may be the result of early modern human migration(s).

New chronology for Ksâr ‘Akil (Lebanon) supports Levantine route of modern human dispersal into Europe

“…Our dates are in good agreement with conventional radiocarbon dates on charcoal (26,40). They also overlap with the age estimates on shell by Douka et al (24) for the upper part of the sequence, but are significantly older (3,000-4,000 y) for the IUP and EUP layers (SI Appendix, Section 2). The reasons behind the observed discrepancy are presently unresolved.…”

“…The antecedence of both UP lithic technocomplexes and modern human remains in the Levant, the latter also corroborated by Manot 1, indicates that modern humans carrying a UP toolkit were present in the Levant before arriving in Europe. This contradicts Douka et al's (24) hypothesis that shell beads, and by proxy UP modern humans, appeared first in Europe. Observed similarities in early UP lithic technology and other material culture of Levantine and European technocomplexes suggest a close interrelation that could well result from dispersal events.…”

“…for Uluzzian ornamental shell in southern Italy (10) and strikingly young ages (around 36,300-37,400 cal B.P.) for shell ornaments from Üçagızlı I and Ksâr 'Akil in the Levant (23,24). If the UP in Europe truly predates the Levantine evidence, as Douka et al (24) suggest, it should be considered unlikely that its makers traveled from Africa through the Levant before arriving in Europe.…”

“…for shell ornaments from Üçagızlı I and Ksâr 'Akil in the Levant (23,24). If the UP in Europe truly predates the Levantine evidence, as Douka et al (24) suggest, it should be considered unlikely that its makers traveled from Africa through the Levant before arriving in Europe. Here, we provide a new chronology for Ksâr 'Akil and show that the earliest UP and its associated AMH remains predate any European evidence.…”

Sir Arthur Keith's Legacy: Re-discovering a lost collection of human fossils

“…Recent research on 42-39Ka old material from the Lebanon (Douka et al, 2013) and 45Ka old teeth from Italy (Benazzi et al, 2011) suggests that humans transitioning to more advanced Upper Palaeolithic tools must have passed through the Levant and expanded into Eurasia somewhere between 60 000 and 45 000 BP (Douka et al, 2013;Mellars, 2011;Stringer, 2012). Despite a good archaeological record (Stringer, 2012), there is a scarcity of modern human skeletal material from the end of the Middle Palaeolithic period (Douka et al, 2013).…”