In archaeogenetics, western hunter-gatherer (WHG, also known as west European hunter-gatherer, western European hunter-gatherer or Oberkassel cluster) () is a distinct ancestral component of modern Europeans, representing descent from a population of Mesolithic hunter-gatherers present across much of Western Europe, Central Europe and parts of Southeastern Europe, from the British Isles in the west to the Carpathians in the east, following the retreat of the ice sheet of the Last Glacial Maximum. It is closely associated and sometimes considered synonymous with the late Upper Paleolithic Villabruna cluster, named after remains found in Ripari Villabruna cave in northern Italy, known from the terminal Pleistocene of Europe, which is largely ancestral to later WHG populations.
WHGs appear to share some genetic affinities with people in West Asia not found in earlier Upper Paleolithic European hunter-gatherers. Their precise relationships to other groups are somewhat obscure, with the origin of the Villabruna cluster likely somewhere in the vicinity of the Balkans. The Villabruna cluster (which is associated with the Epigravettian and other related archaeological cultures of the late Upper Paleolithic) had expanded into the Italian and Iberian Peninsulas by approximately 19,000 years ago, with the WHG cluster subsequently expanding across Western Europe at the end of the Pleistocene around 14–12,000 years ago, largely replacing the Magdalenian peoples who previously dominated the region. These Magdalenian peoples largely descended from earlier Western European Cro-Magnon groups that had arrived in the region over 30,000 years ago, prior to the Last Glacial Maximum.
WHGs constituted one of the main genetic groups in the postglacial period of early Holocene Europe, along with eastern hunter-gatherers (EHG) in Eastern Europe. The border between WHGs and EHGs ran roughly from the lower Danube, northward along the western forests of the Dnieper towards the western Baltic Sea. EHGs primarily consisted of a mixture of WHG-related and Ancient North Eurasian (ANE) ancestry. Scandinavia was inhabited by Scandinavian hunter-gatherers (SHGs), which were a mixture between WHG and EHG. In the Iberian Peninsula, early Holocene hunter-gathers consisted of a mixture of WHG and Magdalenian Cro-Magnon (GoyetQ2) ancestry.
Once the main population throughout Europe, the WHGs were largely replaced by successive expansions of Early European Farmers (EEFs) of Anatolian origin during the early Neolithic, who generally carried a minor amount of WHG ancestry due to admixture with WHG groups during their European expansion. Among modern-day populations, WHG ancestry is the most common among populations of the eastern Baltic region.
WHGs lacked the light skin genes found in modern Europeans and it has been suggested that they were dark skinned and had light coloured eyes.
Research Western hunter-gatherers (WHG) are recognised as a distinct ancestral component contributing to the ancestry of most modern Europeans. Most Europeans can be modeled as a mixture of WHG, EEF, and Western Steppe Herders (WSHs) from the Pontic–Caspian steppe. WHGs also contributed ancestry to other ancient groups such as Early European Farmers (EEF), who were, however, mostly of Anatolian descent. With the Neolithic expansion, EEF came to dominate the gene pool in most parts of Europe, although WHG ancestry had a resurgence in Western Europe from the Early Neolithic to the Middle Neolithic.
Origin and expansion into continental Europe
WHGs represent a major population shift within Europe at the end of the Ice Age, probably a population expansion into continental Europe, from Southeastern European or West Asian refugia. It is thought that their ancestors separated from eastern Eurasians around 40,000 BP, and from Ancient North Eurasians (ANE) prior to 24,000 BP (the estimated age date of the Mal'ta boy). This date was subsequently put further back in time by the findings of the Yana Rhinoceros Horn Site to around 38kya, shortly after the divergence of West-Eurasian and East-Eurasian lineages. Vallini et al. 2022 argues that the dispersal and split patterns of West Eurasian lineages was not earlier than c. 38,000 years ago, with older Initial Upper Paleolithic European specimens, such as those found in the Zlaty Kun, Peștera cu Oase and Bacho Kiro caves, being unrelated to Western hunter-gatherers but closer to Ancient East Eurasians or basal to both.
The relationships of the WHG/Villabruna cluster to other Paleolithic human groups in Europe and West Asia are obscure and subject to conflicting interpretations. A 2022 study proposed that the WHG/Villabruna population genetically diverged from hunter-gatherers in the Middle East and the Caucasus around 26,000 years ago, during the Last Glacial Maximum. WHG genomes display higher affinity for ancient and modern Middle Eastern populations when compared against earlier Paleolithic Europeans such as Gravettians. The affinity for ancient Middle Eastern populations in Europe increased after the Last Glacial Maximum, correlating with the expansion of WHG (Villabruna or Oberkassel) ancestry.
There is also evidence for bi-directional geneflow between WHG and Middle Eastern populations as early as 15,000 years ago. WHG associated remains belonged primarily to the human Y-chromosome haplogroups I-M170 with a lower frequency of C-F3393 (specifically the clade C-V20/C1a2), which has been found commonly among earlier Paleolithic European remains such as Kostenki-14 and Sungir. The paternal haplogroup C-V20 can still be found in men living in modern Spain, attesting to this lineage's longstanding presence in Western Europe. The Villabruna cluster also carried the Y-haplogroup R1b (R1b-L754), derived from the Ancient North Eurasian haplogroup R*, indicating "an early link between Europe and the western edge of the Steppe Belt of Eurasia." Their mitochondrial chromosomes belonged primarily to haplogroup U5.
A 2023 study proposed that the Villabruna cluster emerged from an admixture between a Věstonice-related lineage and a West Eurasian lineage that's basal to the split between Kostenki-14 and Goyet Q116-1 genomes. The Věstonice-related lineage itself can be modeled as a mixture of BK-1653-related lineages and Sunghir-related lineages, with the former being responsible for the high genetic affinities between the Villabruna and Věstonice clusters.(see supplemental material)
Another genetic study models WHG as being predominantly derived from an ancestral source related to the Caucasus Upper Palaeolithic individual from Kotias Klde cave, who can be modeled as a mixture of Upper Paleolithic West Eurasian hunter-gatherer ancestry (76%) and 'ghost' basal Eurasian populations (24%), which was first observed in Neolithic West Asian individuals. The earliest known individuals of predominantly WHG/Villabruna ancestry in Europe are known from Italy, dating to around 17,000 years ago, although an individual from El Mirón cave in northern Spain from about 19,000 years ago had about 43% Villabruna ancestry. While not confirmed, the Villabruna cluster was probably present earlier in the Balkans region than elsewhere in Southern Europe. Early WHG/Villabruna populations are associated with the Epigravettian archaeological culture, which largely replaced populations associated with the Magdalenian culture about 14,000 years ago. The Magdalenian-associated Goyet-Q2 cluster itself primarily descends from earlier Solutrean and western Gravettian-producing groups in France and Spain.
A 2023 study found that relative to earlier Western European Cro-Magnon populations like the Gravettians, the Magdalenian-associated Goyet-Q2 cluster carried significant (c. 30%) Villabruna ancestry even prior to the major expansion of WHG-related groups north of the Alps. This study found that relative to earlier members of the Villabruna cluster from Italy, WHG-related groups which appeared north of the Alps beginning around 14,000 years ago carried around 25% ancestry from the Goyet-Q2 cluster, or alternatively 10% from the western Gravettian associated Fournol cluster. This paper proposed that WHG should be named the Oberkassel cluster, after one of the oldest WHG individuals found north of the Alps.
All Oberkassel-related individuals can be modeled as a mixture of Arene Candide 16 (a 13,000 year old skeleton from Northern Italy representative of Villabruna ancestry) (75%) and Goyet-Q2 (25%) ancestries or Arene Candide 16 (90%) and Fournol 85 (10%) ancestries. Arene Candide 16 is cladal with Epigravettian Europeans whilst Goyet-Q2 and Fournol 85 show affinities with GoyetQ116-1. The study suggests that Oberkassel ancestry was mostly already formed, possibly around the west side of the Alps, before expanding to Western and Central Europe and Britain, where sampled WHG individuals are genetically homogeneous. This is in contrast to the arrival of Villabruna and Oberkassel ancestry to Iberia, which seems to have involved repeated admixture events with local populations carrying high levels of Goyet-Q2 ancestry. This, and the survival of specific Y-DNA haplogroup C1 clades previously observed among early European hunter-gatherers, suggests relatively higher genetic continuity in southwest Europe during this period.
Interaction with other populations
The WHG were also found to have contributed ancestry to populations on the borders of Europe such as early Anatolian farmers and Ancient Northwestern Africans, as well as to other European groups such as eastern hunter-gatherers (EHG). The relationship of WHGs to the EHGs remains inconclusive. EHGs are modeled to derive varying degrees of ancestry from a WHG-related lineage, ranging from merely 25% to up to 91%, with the remainder being linked to geneflow from Paleolithic Siberians (ANE) and perhaps Caucasus hunter-gatherers. Another lineage known as the Scandinavian hunter-gatherers (SHGs) were found to be a mix of EHGs and WHGs.
In the Iberian Peninsula early Holocene hunter-gathers consisted of populations with a mixture of WHG and Magdalenian Cro-Magnon (GoyetQ2) ancestry.
People of the Mesolithic Kunda culture and the Narva culture of the eastern Baltic were a mix of WHG and EHG, showing the closest affinity with WHG. Samples from the Ukrainian Mesolithic and Neolithic were found to cluster tightly together between WHG and EHG, suggesting genetic continuity in the Dnieper Rapids for a period of 4,000 years. The Ukrainian samples belonged exclusively to the maternal haplogroup U, which is found in around 80% of all European hunter-gatherer samples.
People of the Pit–Comb Ware culture (CCC) of the eastern Baltic were closely related to EHG. Unlike most WHGs, the WHGs of the eastern Baltic did not receive European farmer admixture during the Neolithic. Modern populations of the eastern Baltic thus harbor a larger amount of WHG ancestry than any other population in Europe.
SHGs have been found to contain a mix of WHG components who had likely migrated into Scandinavia from the south, and EHGs who had later migrated into Scandinavia from the northeast along the Norwegian coast. This hypothesis is supported by evidence that SHGs from western and northern Scandinavia had less WHG ancestry (ca 51%) than individuals from eastern Scandinavia (ca. 62%). The WHGs who entered Scandinavia are believed to have belonged to the Ahrensburg culture. EHGs and WHGs displayed lower allele frequencies of SLC45A2 and SLC24A5, which cause depigmentation, and OCA/Herc2, which causes light eye color, than SHGs.
The DNA of eleven WHGs from the Upper Palaeolithic and Mesolithic in Western Europe, Central Europe and the Balkans was analyzed, with regards to their Y-DNA haplogroups and mtDNA haplogroups. The analysis suggested that WHGs were once widely distributed from the Atlantic coast in the West, to Sicily in the South, to the Balkans in the Southeast, for more than six thousand years.