Abstract
During the Late Iron Age (La Tène, 4th-1st centuries BCE), various human groups sharing cultural elements, commonly referred to as "Celts", were involved in migration processes and settled in the Italian Peninsula after crossing the Alps. The current knowledge of these people is largely drawn from osteological, isotopic, archaeological, and historical evidence. However, the genetic history of these groups from both north and south of the Alps remains unexplored.
This paleogenomic study aims to analyze if the cultural similarity of these people is reflected in their genomic makeup. Moreover, it intends to study the genetic relationships between different La Tène groups from north and south of the Alps, and other ancient and present-day populations from Europe.
We performed molecular analyses (shotgun and nuclear capture data – approx. 1.3 mio SNPs) on 194 individuals from 13 Swiss and North-Italian Late Iron Age archaeological contexts. Ancient DNA data allows to determine the genetic sex in 119 individuals, comprising 76 XX and 43 XY, including 52 subadults. With the additional support of mitochondrial DNA data, we detected genetic relatedness among three individual pairs within two different Swiss archeological sites, and one case in the North-Italian site of Seminario Vescovile.
Comparative analyses show a genetic similarity between the ancient Swiss and Italian individuals. Additionally, their genomic diversity overlaps with that of especially western and south-western European present-day populations. However, the results suggest a genetic discontinuity between Late Iron Age individuals from Northern Italy and present-day populations from the same geographic area. On the other hand, the comparison with published data infers a stronger genetic affinity among European Iron Age groups.