Abstract
The compilation of archaeological and genetic data for ancient European human groups has provided persuasive evidence for a complex series of migrations, population replacements and admixture until the Bronze Age. If the Bronze-to-Iron Age transition has been well documented archaeologically, ancient DNA (aDNA) remains rare for the latter period and does not precisely reflect the genetic diversity of European Celtic groups. In order to document the evolution of European communities, we analysed 45 individuals from the Late Iron Age (La Tène) Urville-Nacqueville necropolis in northwestern France, a region recognized as a major cultural contact zone between groups from both sides of the Channel. The characterization of 37 HVS-I mitochondrial sequences and 40 haplogroups provided the largest maternal gene pool yet recovered for the European Iron Age. First, descriptive analyses allowed us to demonstrate the presence of substantial amounts of steppe-related mitochondrial ancestry in the community, which is consistent with the expansion of Bell Beaker groups bearing an important steppe legacy in northwestern Europe at approximately 2500 BC. Second, maternal genetic affinities highlighted with Bronze Age groups from Great Britain and the Iberian Peninsula regions tends to support the idea that the continuous cultural exchanges documented archaeologically across the Channel and along the Atlantic coast (during and after the Bronze Age period) were accompanied by significant gene flow. Lastly, our results suggest a maternal genetic continuity between Bronze Age and Iron Age groups that would argue in favour of a cultural transition linked to progressive local economic changes rather than to a massive influx of allochthone groups. The palaeogenetic data gathered for the Urville-Nacqueville group constitute an important step in the biological characterization of European Iron age groups. Clearly, more numerous and diachronic aDNA data are needed to fully understand the complex relationship between the cultural and biological evolution of groups from the period.
Highlights
The confrontation between the complementary archaeological and ancient DNA arguments provides invaluable insights into the role of biological processes in major cultural changes identified in the archaeological record
Multidisciplinary approaches test the potential correlation betweenregional cultural groups and genetically differentiable individuals, or to what extent the cultural hiatuses documented for diverse periods were linked to human population turnover. The compilation of such combined data for European human groups from the Palaeolithic to the Bronze Age period have provided persuasive evidence for a complex series of expansions, population replacements and resurgences, and admixture between divergent groups. This complex biological evolution resulted in the fact that the great majority of European populations’ ancestry derived from three distinct sources: (i) a “hunter-gatherer”-related ancestry inherited mainly from Mesolithic human groups, (ii) a “Neolithic farmer”-related ancestry linked to the migration of farmers originating from northwestern Anatolia and linked to the Neolithic expansion into Europe, and (iii) a “steppe-related”-ancestry reflecting the expansion into Europe during the third millennium BE of pastoralist groups originating from the Pontic-Caspian steppes and presenting genetic affinities with individuals associated with the Yamnaya complex [2,3,4]
Palaeogenomic studies focusing on the Late Neolithic-to-Bronze Age transition have shown that up to 75% of the ancestry of individuals associated with the Corded Ware and Bell Beaker complexes in northern and northwestern Europe could be traced to populations originating from the steppes [2,3]
Summary
The confrontation between the complementary archaeological and ancient DNA (aDNA) arguments provides invaluable insights into the role of biological processes in major cultural changes identified in the archaeological record. The compilation of such combined data for European human groups from the Palaeolithic to the Bronze Age period have provided persuasive evidence for a complex series of expansions, population replacements and resurgences, and admixture between divergent groups (see Harris 2017 [1] for a recent review) This complex biological evolution resulted in the fact that the great majority of European populations’ ancestry derived from three distinct sources: (i) a “hunter-gatherer”-related ancestry inherited mainly from Mesolithic human groups, (ii) a “Neolithic farmer”-related ancestry linked to the migration of farmers originating from northwestern Anatolia and linked to the Neolithic expansion into Europe, and (iii) a “steppe-related”-ancestry reflecting the expansion into Europe during the third millennium BE of pastoralist groups originating from the Pontic-Caspian steppes and presenting genetic affinities with individuals associated with the Yamnaya complex [2,3,4]. This major genetic transformation is detected through the evolution of uniparental markers (mitochondrial DNA -mtDNA- and Y-chromosome), with Neolithic haplogroups being replaced by new maternal (I, T1, U2, U4, U5a, W and subtypes of H) and paternal (R1a and R1b) lineages originating from eastern regions [2,3]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
