Genetic mapping challenges the origin of Celtic languages

A research team led by paleogeneticist Eske Willerslev of the Globe Institute in Copenhagen, Denmark, used paleogenomics to trace the expansion of Celtic populations and languages across Europe.

The researchers analyzed the genomes of 4587 individuals to identify ancestral lineages and movement patterns. This data allowed the team to evaluate four existing theories regarding whether Celtic languages originated in Central Europe, along the Atlantic coast, or in France and Italy.

The study found that Celtic expansion was not a single event but a series of long-term processes. The researchers identified early movements from "Western" and "Central" Celtic regions toward Great Britain starting 3800 years ago, followed by movements from "Eastern" regions approximately 3200 years ago. The team also noted a significant genetic flow from Central Europe toward France and northeast Spain between 3200 and 2800 years ago, which coincided with the spread of the Urnfield culture.

The findings favor a model where Celtic populations originated in Eastern Europe rather than the Atlantic coast or France. However, the researchers noted that linguistic identity cannot be directly deduced from genetic data alone. They suggested that Celtic languages may have spread through the gradual adoption of linguistic traits rather than the complete replacement of local languages.

Because of these complex layers of migration and mixing, the team concluded that a single "motherland" for the Celtic languages remains impossible to pinpoint.