Parallel societies or farming transition in the Müllerthal area? Loschbour and his descendants

Most prehistoric human remains from Luxembourg have been recovered in the Müllerthal (Figure 2), including the 8200-year-old Loschbour skeleton, discovered by Nicolas Thill in 1935. This region is characterised by deep river valleys lined by sandstone bluffs, dense tree cover, and a unique system of rockshelters and diaclase caves. Given the limited evidence for agriculture in the Müllerthal prior to Roman times, its use for burial activities during the Neolithic, Bronze and Iron Age remains enigmatic, although some caves and rockshelters show signs of occupation or symbolic activities in the form of deep, stratified sequences, hearths and artefact assemblages (Heuertz Reference Heuertz1969).

A key question for the current project is whether Late Mesolithic foragers inhabiting the region were displaced or absorbed by incoming farmers following the Neolithic Transition. Previous research in the Blätterhöhle Cave, roughly 200km to the north-east of our study area in Germany, has indicated that farmers and foragers lived side-by-side for centuries, with genetic signals of asymmetric admixture (Bollongino et al. Reference Bollongino2013; Lipson et al. Reference Lipson2017). While early third millennium BC genomes from the Müllerthal area cluster with European Neolithic farmers on a PCA, they also show a significant shift towards WHGs like Loschbour (Figure 3). Further research should clarify whether WHG ancestry in Luxembourg genomes exceeds expectations under a model of broader re-emergence at continental level of WHG ancestry in Middle and Late Neolithic genomes (Lipson et al. Reference Lipson2017). The rockshelter site of Atsebach (genomes labelled as ‘HEA’ on Figure 3), less than a kilometre from Loschbour, is a prime candidate for genomic analysis, having yielded several well-preserved inhumations, some dating back to the early third millennium BC.

The Rhine-Meuse corridor and the Beaker phenomenon in North-west Europe

Nested between France, Germany and Belgium on the Moselle River, Luxembourg has yielded prehistoric burials of international significance, notably the double Beaker-period grave of Altwies, in south Luxembourg, which resembles in layout the so-called ‘echinoid burial’ of Dunstable Downs, in south Bedfordshire, England. Collective graves were increasingly replaced during the third millennium BC by single pit graves, and characterised by repetitive burial assemblages, including the eponymous S-shaped beakers (Figure 4). Discovered in 2000 during rescue excavations on Highway A13 to Germany, the Altwies grave is one of two Late Neolithic burials cut into cultural deposits from an older Linearbandkeramik settlement (Le Brun-Ricalens et al. Reference Le Brun-Ricalens2001).

Figure 4.

Altwies-“Op dem Boesch”; beaker associated with the adult-child burial (Le Brun-Ricalens et al. Reference Le Brun-Ricalens, Toussaint, Valotteau, Salanova and Tchérémissinoff2011: fig. 70; © Institut National de Recherches Archéologiques).

Grave 2, depicted in Figure 5, is thought to belong to a ‘mother’ and her ‘child’. Preliminary shallow sequencing of ancient DNA has confirmed the biological sex of the adult as female and the child as male. The grave is being re-examined within the wider European context of ‘steppe’ dispersals from a hypothetical core area in the Pontic-Caspian region. As with the two partial genomes from the Mondelange necropolis in the French Moselle area included in the study by Olalde and colleagues (Reference Olalde2018), the Altwies genomes have revealed high levels of ‘steppe-derived’ ancestry, suggesting that the Rhine-Meuse region experienced significant gene flow from populations further east (Figure 6). The presence of All-Over-Cord (AOC) Beakers in Britain has long been seen as an indication of a direct link, if not outright migration, from the Rhineland region, via the Low Countries (Harrison Reference Harrison1974). Such a hypothesis can now be tested using high-coverage ancient genomes from Luxembourg. The Beaker-period skeletons of Dunstable Downs, uncovered in 1887 (Smith Reference Smith1894), were sampled by the authors in Luton Museum in 2022, and DNA was successfully extracted.

Figure 5.

Adult-child burials sampled for this project, Bell Beaker period: A) Altwies-‘‘Op dem Boesch’’, Luxembourg (Le Brun-Ricalens et al. Reference Le Brun-Ricalens, Toussaint, Valotteau, Salanova and Tchérémissinoff2011: fig. 71; © Institut National de Recherches Archéologiques); B) Dunstable Downs, Southern Bedfordshire, United Kingdom (Smith Reference Smith1894: frontispiece).

Figure 6.

The Luxembourg Bell Beaker genomes modelled as a mixture of Western Hunter-Gatherers, Aegean farmers and Yamnaya steppe ancestry components with qpAdm (figure by Y. Diekmann).

Future work

Deeper sequencing of the human genomes from Dunstable Downs is expected to take place in 2023. Population genetic analyses of the ancient genomes are ongoing. Archaeological work is continuing in parallel to contextualise the results and test the hypotheses outlined in this article.