Available online at www.sciencedirect.com C. R. Palevol 8 (2009) 503–509 Human Palaeontology and Prehistory (Palaeopopulations, Palaeogenetics, Migrations) Ebb and flow or regional extinctions? On the character of Neandertal occupation of northern environments Jean-Jacques Hublin a,∗, Wil Roebroeks b a Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany b Leiden University, Faculty of Archaeology, P.O. Box 9515, 2300RA Leiden, The Netherlands Received 26 October 2008; accepted after revision 7 April 2009 Presented by Yves Coppens Abstract In the course of the last 500,000 years, the Neandertal lineage was the first human group to extensively colonize the middle latitudes of western Eurasia up to 55◦ N. Although Neandertals were able to adapt to a variety of environments, their ability to cope with extreme glacial environments seems to have been very limited. Depending on the climatic cycles, their presence in the northern environments was essentially discontinuous. The periodical abandonment of some areas is generally interpreted as resulting in a movement of northern populations into southern refuges and a subsequent recolonisation of the northern regions. Here, we argue that the current palaeo-ecological, archaeological and palaeogenetic evidence supports a model of local extinctions rather than a habitat tracking model. To cite this article: J.-J. Hublin, W. Roebroeks, C. R. Palevol 8 (2009). © 2009 Académie des sciences. Published by Elsevier Masson SAS. All rights reserved. Résumé Flux et reflux ou extinctions régionales ? Sur la nature du peuplement néandertalien dans les environnements septentri- onaux. Au cours des derniers 500 000 ans, la lignée néandertalienne représente le premier groupe humain à coloniser de fac¸on significative les moyennes latitudes d’Eurasie occidentale jusqu’à 55◦ N. Bien que les néandertaliens se soient adaptés à des envi- ronnements variés, leur capacité à survivre dans des environnements glaciaires extrêmes semblent avoir été très limitée. Au gré des cycles climatiques, leur occupation des zones septentrionales fut essentiellement discontinue. Ces abandons périodiques de territoires sont généralement interprétés comme un mouvement de populations vers des zones refuges méridionales, suivi par une recolonisation des zones septentrionales. En réalité, les données paléo-écologiques, archéologiques et paléogénétiques plaident en faveur d’un modèle d’extinctions locales, plutôt qu’en faveur d’un modèle de suivi des déplacements du biotope. Pour citer cet article : J.-J. Hublin, W. Roebroeks, C. R. Palevol 8 (2009). © 2009 Académie des sciences. Publie´ par Elsevier Masson SAS. Tous droits réservés. Keywords: Neandertal; Climate; Demography; Mousterian; Glaciation; Interglacial; Refuge Mots clés : Néandertal ; Climat ; Démographie ; Moustérien ; Glaciation ; Interglaciaire ; Refuge 1. Introduction ∗ Corresponding author. The Neandertal lineage represents a human clade that E-mail address: [email protected] (J.-J. Hublin). separated from the one leading to extant humans about 1631-0683/$ – see front matter © 2009 Académie des sciences. Published by Elsevier Masson SAS. All rights reserved. doi:10.1016/j.crpv.2009.04.001 504 J.-J. Hublin, W. Roebroeks / C. R. Palevol 8 (2009) 503–509 half a million years ago [20]. To date, it is exclusively western Europe show that Neandertals were able to adapt documented in Eurasia; the Mediterranean seems to have to a wide range of environments, from full interglacial played a crucial role in the segregation of the two clades. conditions such as at Caours (France) [2] and from Although humans are documented in Eurasia since at the present excavations at Neumark-Nord (Germany) least 1.7 my BP [37], the colonisation of the middle [14] to significantly colder contexts, as at Beauvais and and high latitudes resulted from a long process. The few Hénin-sur-Cojeul (France) [26]. Meanwhile, Neander- well-demonstrated sites of European Early Pleistocene tals are absent in most of northwestern Europe at the human occupation are thus far only found in the Mediter- peak of glacial events. The archaeological record shows ranean area. With the exception of earlier brief episodes important hiatuses in the presence of Middle Palaeolithic related to warmer climatic conditions [29], the Neander- hominins, especially during the pleniglacial climatic tal lineage was the first to colonise northern temperate conditions of MIS 4 (as well as for earlier colder periods, latitudes, up to 55◦ N, in a wide range of environmental e.g. MIS 6), which cannot be explained by taphonomic settings. The exact limits of their range are difficult to processes, as these are the periods with the highest rate of outline, due not only to differences in site preservation loess formation, and hence the best preservation poten- but also to research history and intensity. These differ- tial. ences apply especially to their eastern limits, which have The standard explanation for this distribution pat- recently moved 2000 kilometers eastward, as a result of tern is that contraction of the habitable areas would new genetic analysis of morphologically unidentifiable have led to the displacement of Neandertal populations fossil skeletal remains [24]. The majority of their fossils into refuges, which are usually inferred to have been in have been unearthed in the westernmost parts of their the “South”. Middle Palaeolithic hominins would have range, but current views of ‘core’ and ‘marginal’ areas in tracked their preferred habitats, ‘overwintered’ the cold their distribution may change through future fieldwork in climatic conditions in southern areas, and recolonised Asia. Distribution maps like those published by Krause the northern plains when environmental conditions ame- et al. [24] are coarse-grained palimpsests, compound- liorated. This ‘ebb and flow’ of populations would ing many phases of range expansion and contraction explain the great richness of Neandertal fossils in the on maps that give only a rough approximation of the south. For example, in France the majority of the 56 former distribution of the species. Within these rough Late Pleistocene Neandertal specimens were found in limits, Neandertal presence must have varied, from con- the southern half [28]. More importantly, archaeolog- tinuous presence in some limited areas up to periodical ical data from southern France, and specifically from excursions into many others, with total abandonment Aquitaine, suggest that there was always a hominin pres- when environmental conditions deteriorated. This ‘ebb ence between approximately 350 and 35 ka, in glacial and flow’ of occupation has been well documented in the as well as interglacial settings [48]. And this pattern westernmost part of the Neandertal world, where more survived into the last glacial maximum, after anatom- than one and a half centuries of multidisciplinary stud- ically modern humans replaced the Neandertals in ies of the fossil and archaeological record have created a Europe [4]. rich database on Neandertal presence and absence, espe- For the colder phases of the glacial-interglacial cially detailed for the Late Pleistocene, i.e. from MIS 5e cycles, we have indications that large parts of the Nean- to MIS 3. The record from this time range is very rich in dertal range in northern Europe were deserted, with northern France, where large-scale excavations over the Neandertals maintaining core populations in the south. last three decades have uncovered more than 50 late Mid- However, one can question the evidence for the ‘ebb and dle Palaeolithic sites between the valleys of the Somme flow’ pattern of Neandertal peopling with northern Nean- and Meuse rivers. dertals moving southward to refuges, from which the Neandertal sites are usually retrieved from sediments north was colonised again. What are the arguments for deposited in cool to cold environments. This should not such two-way hominin traffic, caused by expansion and come as a surprise, as 95% of the last 0.5 my wit- contraction of available territory? If, for argument’s sake, nessed colder conditions than the present day ones, with we assume that the south harboured refuge areas, were the exceptions of the interglacials MIS11 and MIS 5e. the southern regions accessible for the northern popu- Partly because of this climatic environment and partly lations? After all, there were already Neandertals living because of limited technological ways to respond to in the south. Here we suggest that it is worthwhile to thermic stress, known postcranial Neandertal remains investigate an alternative hypothesis to the habitat track- are generally interpreted as demonstrating cold-adapted ing model: northern populations may simply have gone body proportions [19,44]. However, data from north- extinct. J.-J. Hublin, W. Roebroeks / C. R. Palevol 8 (2009) 503–509 505 2. Neandertal ecology and demographic pattern Neandertals therefore appear to be highly carnivorous and at the top of the continental trophic chain. Recent advances in the understanding of Neandertal Another possible consequence of their high DEE is ecology provide us with some arguments to test the two their high residential mobility. Following Verpoorte [49], alternatives. Neandertals were large-bodied hominins MacDonald et al. [27] have argued that because of the with an average body mass surpassing that observed in combination of a high DEE (at least 10% higher than that most recent human populations. Even when compared of