In a study published on July 27, 2017, by Daniel Bradley, Rui Martiniano of Trinity College Dublin, and Ana Maria Silva of the University of Coimbra, Portugal, it was revealed that the genomes of individuals from the Bronze Age in the Iberian Peninsula showed minor genetic influence from Steppe invaders. This suggests that migrations from the Steppe played a comparatively smaller role in shaping the genetic and cultural landscape of Iberian people in comparison to other regions in Europe.
During the transition from the Middle Neolithic (4200-3500 BC) to the Middle Bronze Age (1740-1430 BC), Central and Northern Europe experienced significant population movements from the Steppe regions of Eastern Europe and Asia. While archaeological evidence in Iberia indicated cultural and funeral ritual changes during this period, the genetic impact had not been thoroughly explored. The researchers sequenced the genomes of 14 individuals from Portugal spanning the Neolithic and Bronze Ages, comparing them with both ancient and modern genomes.
In contrast to other European regions, the study identified only subtle genetic changes between Neolithic and Bronze Age samples in Portugal, suggesting a limited impact from small-scale migrations. Notably, these changes were more pronounced in the paternal lineage, revealing a significant Y chromosome discontinuity consistent with a primarily male-mediated genetic influx, a surprising observation according to Rui Martiniano, the first author of the study. The researchers also used relevant DNA sequences to estimate height from the samples, finding that genetic input from Neolithic migrants correlated with a decrease in the height of Europeans, which subsequently increased in later generations.
The study indicates that migration into the Iberian Peninsula during this period occurred on a much smaller scale compared to the Steppe invasions in other parts of Northern, Central, and Northwestern Europe. This discrepancy in migration scale is thought to have implications for the spread of language, culture, and technology. The findings may help explain the persistence of a pre-Indo-European language, Euskera, spoken in the Basque region along the Spain-France border, in Iberia. The traditional model suggesting the spread of Indo-European languages through Europe from the Steppe heartland aligns with these results.
Daniel Bradley notes, “Unlike further north, a mix of earlier tongues and Indo-European languages persist until the dawn of Iberian history, a pattern that resonates with the real but limited influx of migrants around the Bronze Age.” These insights shed light on the nuanced dynamics of population movements and their lasting impact on the genetic and cultural diversity of different regions in Europe during critical periods of prehistory.
Source: Public Library of Science