Investigating Neanderthal dispersal above 55°N in Europe during the Last Interglacial Complex

Abstract

When dealing with the northern boundary of Neanderthals (Homo neanderthalensis) and the question of whether or not they dispersed into Southern Scandinavia, two contradictory hypotheses can be identified. The first, and also the most widely endorsed, hereafter, hypothesis A, argues primarily that Neanderthals did not occupy regions above 55°N because of 1) climatic constraints and 2) dispersal barriers. The second, hypothesis B, argues that they possibly occasionally dispersed above 55°N, but that factors such as 1) research- and/or 2) taphonomic bias are responsible for their archaeological invisibility. Here, we report an evaluation of these competing hypotheses. To this end, we reconstruct the environment for the time period and region of interest (the Last Interglacial Complex and Northern Germany and Southern Scandinavia), based on three lines of evidence: palaeoenvironmental reconstruction combined with a novel habitat modelling approach, a review of relevant archaeological localities, and a discussion of the possible impacts of both research biases and the taphonomic effects on the archaeological data. We focus particularly on the climatic and geological explanatory factors relevant to the two hypotheses. Our results are inconsistent with the claim that climatic constraint and/or a lack of suitable habitats can fully explain the absence of Neanderthals in Southern Scandinavia during the Eemian Interglacial and Early Weichselian Glaciation. We do, however, find evidence that a geographic barrier may have impeded northerly migrations during the Eemian. The evidence reviewed here suggests that both research bias and taphonomy – consistent with hypothesis B – could account for the archaeological invisibility of Neanderthals in Southern Scandinavia, highlighting the need for further strategic survey and/or excavation efforts in the region.