Ebb and flow or regional extinctions? On the character of Neandertal occupation of northern environments

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. RésuméFlux et reflux ou extinctions régionales ? Sur la nature du peuplement néandertalien dans les environnements septentrionaux. Au cours des derniers 500 000 ans, la lignée néandertalienne représente le premier groupe humain à coloniser de façon significative les moyennes latitudes d'Eurasie occidentale jusqu'à 55• N. Bien que les néandertaliens se soient adaptés à des environnements 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.

Morphological description and comparison of the dental remains from Atapuerca-Sima de los Huesos site (Spain)

“…Alternatively, the highly derived and Neanderthal character of the Sima de los Huesos dentitions, if we accept the early Middle Pleistocene date attributed to the site, might suggest that SH has played a major role as a core or source population for the Nean derthal gene pool, particularly in the frame of an evolutionary scenario with common bottlenecks, as has been suggested for this lineage (see Hublin, 1996Hublin, , 2009Hublin and Roebroeks, 2009). In this scenario, Neanderthals would be a terminal species belonging to a wider European hominin radiation (Schwartz and Ta ttersall, 2005), and SH (but not other Middle Pleistocene European pop ulations) would be at the root of the classic Neanderthal group.…”

“…Until then, we believe that the available evidence compels us to at least explore alternative models to the "accretion model" in order to better understand the emergence of the Neanderthal lineage. Complex demographic patterns driven by the climatic conditions and implying extinctions, recolonizations (Hublin and Roebroeks, 2009), and mixing between demes with different degrees of "neanderthalization" (for a more detailed explanation, see Dennell et al, 2010) could explain the variability of the Middle Pleistocene groups and the apparently non-lineal evolution toward H. neanderthalensis.…”

The origin of Neandertals

“…In fact, Neandertals seem limited in their ability to live on peri-arctic landscapes. During cold episodes such as OIS 6 and OIS 4, large portions of the European territory were abandoned and later recolonized (9,10). Different estimates suggest that the Neandertal populations had very low densities and limited resilience (11).…”

Evidence for the Blake Event recorded at the Eemian archaeological site of Caours, France

“…Although there is plenty of evidence suggesting that Neandertals were able to colonize middle latitudes up to 55 N, it has been suggested that their presence in northern environments was discontinuous and strongly influenced by climatic fluctuations (Hublin and Roebroeks, 2009). Environmental degradation may have obliged H. neanderthalensis to search for southern refuges for survival, although local extinctions due to the harsh climatic conditions cannot be excluded either (e.g.…”

“…Environmental degradation may have obliged H. neanderthalensis to search for southern refuges for survival, although local extinctions due to the harsh climatic conditions cannot be excluded either (e.g. Hublin and Roebroeks, 2009;Roebroeks et al, 2011).…”