New Publication: Five Thousand Years of Population History in Portugal

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We’re excited to share our latest research published in Genome Biology, presenting the most comprehensive collection of ancient genomic data from Portugal to date. This collaborative study analysed 67 individuals spanning 5,000 years of human history, from the Neolithic to the nineteenth century, revealing dynamic patterns of migration, admixture, and genetic continuity at the westernmost edge of continental Eurasia.

Portugal occupies a unique geographical position at the westernmost tip of Europe, serving as both a terminal destination for continental migrations and a gateway for maritime connections across the Mediterranean and Atlantic. Despite its strategic importance, Portuguese ancient DNA data has been notably underrepresented in recent large-scale studies of Iberian population history. This work addresses that gap, providing unprecedented insights into the genetic transformations that accompanied major cultural and historical transitions in the region.

Abstract

Background

Recent ancient DNA studies uncovering large-scale demographic events in Iberia have presented very limited data for Portugal, a country located at the westernmost edge of continental Eurasia. Here, we present the most comprehensive collection of Portuguese ancient genome-wide data, from 67 individuals spanning 5000 years of human history, from the Neolithic to the nineteenth century.

Results

We identify early admixture between local hunter-gatherers and Anatolian-related farmers in Neolithic Portugal, with a northeastern–southwestern gradient of increasing Magdalenian-associated ancestry persistence in Iberia. This profile continues into the Chalcolithic, though Bell Beaker-associated sites reveal Portugal’s first evidence of Steppe-related ancestry. Such ancestry has a broader demographic impact during the Bronze Age, despite continuity of local Chalcolithic genetic ancestry and limited Mediterranean connections. The village of Idanha-a-Velha emerges in the Roman period as a site of significant migration and interaction, presenting a notably diverse genetic profile that includes North African and Eastern Mediterranean ancestries. The Early Medieval period is marked by the arrival of Central European genetic diversity, likely linked to migrations of Germanic tribes, adding to coeval local, African, and Mediterranean influences. The Islamic and Christian Conquest periods show strong genetic continuity in northern Portugal and significant additional African admixture in the south. The latter remains stable during the post-Islamic period, suggesting enduring African influences.

Conclusions

We reveal dynamic patterns of migration in line with cultural exchange across millennia, but also the persistence of local ancestries. Our findings integrate genetic information with historical and archeological data, enhancing our understanding of Iberia’s biological and cultural heritage.

Key Findings

  • Neolithic Transitions: Evidence of early admixture between Western Hunter-Gatherers and incoming Anatolian-related farmers, with a gradient of Magdalenian ancestry persistence from northeast to southwest Iberia

  • Steppe Ancestry Arrival: First detection of Steppe-related ancestry in Portugal during the Chalcolithic period, associated with Bell Beaker culture sites, with broader demographic impact during the Bronze Age

  • Roman Period Diversity: Idanha-a-Velha emerges as a cosmopolitan hub with remarkable genetic diversity, including North African and Eastern Mediterranean ancestries, reflecting the village’s role in Roman trade networks

  • Medieval Transformations: Introduction of Central European genetic diversity during the Early Medieval period, likely associated with Germanic migrations, overlaying existing local, African, and Mediterranean influences

  • Islamic Period Legacy: Strong genetic continuity in northern Portugal contrasting with substantial African admixture in southern regions during Islamic rule, with this southern African ancestry remaining stable through the post-Islamic period

  • 5000 Years of Continuity: Despite waves of migration and admixture, evidence of persistent local genetic ancestry throughout Portuguese history, demonstrating both dynamic change and remarkable continuity

Significance

This study represents the most comprehensive ancient DNA dataset from Portugal published to date, integrating genomic data with archaeological and historical evidence to illuminate:

  • The mechanisms and timing of major prehistoric and historic migrations into Iberia
  • Regional patterns of genetic diversity and admixture across different time periods
  • The enduring influence of historical events on modern Portuguese genetic structure
  • The role of Portugal as both a destination and crossroads for human migration

By combining genetic analysis with archaeological context and historical documentation, this work provides a nuanced understanding of how human populations at Europe’s Atlantic edge responded to and shaped broader continental and Mediterranean demographic processes.

Data Availability

All ancient genomic data generated in this study have been made publicly available through the European Nucleotide Archive (ENA), ensuring the research can be built upon by the wider scientific community.

📄 Read the Full Open-Access Paper

Journal: Genome Biology
Published: 15 January 2025
DOI: 10.1186/s13059-025-03707-2