Tracing the spread of Celtic languages using ancient genomics

bioRxiv (Cold Spring Harbor Laboratory)

Abstract

Summary Celtic languages, including Irish, Scottish Gaelic, Welsh and Breton, are today restricted to the Northern European Atlantic seaboard. However, between three and two thousand years before present (BP), Celtic was widely spoken across most of Europe before being largely replaced by Germanic, Latin or Slavic 1–4 . Despite this rich history, how Celtic spread across the European continent remains contentious 5 . The debate is currently focused around three main models based on historical linguistics and archaeology: (1) a Late Bronze Age/Early Iron Age spread from Central Europe associated with the Hallstatt and La Tène Cultures 6–9; (2) a Late Neolithic/Early Bronze Age spread along the Atlantic seaboard linked to the Bell Beaker Culture 10–13; and (3) a Bronze Age spread from France, Iberia or Northern Italy 14–16 . Previous genomic investigations are centred around the arrival of Celtic to specific regions: Britain 17 , Iberia 18 and Southwestern Germany 19 . Here, we utilise new genomic data from Bronze and Iron Age Europe to test how the population histories align with the three models of prehistoric spread of the Celtic languages. In line with the theory that Celtic spread from Central Europe during the Late Bronze Age to Early Iron Age, we find Urnfield-related ancestry – specifically linked to the Knovíz subgroup to have formed between 4 and 3.2 kyr BP, and subsequently expanded across much of Western Europe between 3.2 and 2.8 kyr BP. This ancestry further persisted into the Hallstatt Culture of France, Germany and Austria, impacting Britain by 2.8 kyr BP and Iberia by 2.5 kyr BP. Our findings thus agree with the model of Central European spread of the Celtic languages through consecutive expansions of the Urnfield, Hallstatt and La Tène Cultures rather than the competing models. These results demonstrate, yet again, the power of ancient population genomics in addressing long-standing debates in historical linguistics and archaeology.

Authors 10

1. Hugh McColl

   University of Copenhagen · Lundbeck Foundation · University of Gothenburg

   Affiliation as printed

   Department of Historical Studies, University of Gothenburg, Gothenburg, Sweden

   Lundbeck Foundation GeoGenetics Center, Globe Institute, University of Copenhagen, Copenhagen, Denmark

2. Guus Kroonen Aachen

   Leiden University · University of Copenhagen

   Affiliation as printed

   Department of Nordic Studies and Linguistics, University of Copenhagen, Copenhagen, Denmark

   Leiden University Centre for Linguistics, Leiden University, Leiden, The Netherlands

3. Thomaz Pinotti

   Universidade Federal de Minas Gerais · University of Copenhagen · Lundbeck Foundation

   Affiliation as printed

   Laboratório de Biodiversidade e Evolução Molecular (LBEM), Universidade Federal de Minas Gerais, Belo Horizonte, Brazil

   Lundbeck Foundation GeoGenetics Center, Globe Institute, University of Copenhagen, Copenhagen, Denmark

4. William Barrie

   University of Cambridge

   Affiliation as printed

   Department of Genetics, University of Cambridge, Cambridge, United Kingdom

5. John Thomas Koch

   Aberystwyth University · University of Wales

   Affiliation as printed

   University of Wales Centre for Advanced Welsh and Celtic Studies, Aberystwyth, UK

6. Johan Ling

   University of Gothenburg

   Affiliation as printed

   Department of Historical Studies, University of Gothenburg, Gothenburg, Sweden

7. Jean-Paul Demoule

   Université Paris 1 Panthéon-Sorbonne

   Affiliation as printed

   UMR 8215 CNRS, Germany

   University of Paris I - Panthéon-Sorbonne, France

8. Kristian Kristiansen

   University of Copenhagen · Lundbeck Foundation · University of Gothenburg

   Affiliation as printed

   Department of Historical Studies, University of Gothenburg, Gothenburg, Sweden

   Lundbeck Foundation GeoGenetics Center, Globe Institute, University of Copenhagen, Copenhagen, Denmark

9. Martin Sikora

   University of Copenhagen · Lundbeck Foundation

   Affiliation as printed

   Lundbeck Foundation GeoGenetics Center, Globe Institute, University of Copenhagen, Copenhagen, Denmark

10. Eske Willerslev corresponding

    University of Copenhagen · University of Bremen · University of Cambridge · Lundbeck Foundation

    Affiliation as printed

    Department of Genetics, University of Cambridge, Cambridge, United Kingdom

    Lundbeck Foundation GeoGenetics Center, Globe Institute, University of Copenhagen, Copenhagen, Denmark

    MARUM, University of Bremen, Germany