High Y-chromosomal diversity and low relatedness between paternal lineages on a communal scale in the Western European Low Countries during the surname establishment

Abstract

There is limited knowledge on the biological relatedness between citizens and on the demographical dynamics within villages, towns and cities in pre-17th century Western Europe. By combining Y-chromosomal genotypes, in-depth genealogies and surname data in a strict genetic genealogical approach, it is possible to provide insights into the genetic diversity and the relatedness between indigenous paternal lineages within a particular community at the time of the surname adoption. To obtain these insights, six Flemish communities were selected in this study based on the differences in geography and historical development. After rigorous selection of appropriate DNA donors, low relatedness between Y chromosomes of different surnames was found within each community, although there is co-occurrence of these surnames in each community since the start of the surname adoption between the 14th and 15th century. Next, the high communal diversity in Y-chromosomal lineages was comparable with the regional diversity across Flanders at that time. Moreover, clinal distributions of particular Y-chromosomal lineages between the communities were observed according to the clinal distributions earlier observed across the Flemish regions and Western Europe. No significant indication for genetic differences between communities with distinct historical development was found in the analysis. These genetic results provide relevant information for studies in historical sciences, archaeology, forensic genetics and genealogy.

Figure 1

Map of the study area. The coloured area in light grey represents Flanders (including the selected adjacent parts of the Dutch provinces—Zeeland and Limburg); the areas coloured in darker grey are the regions northern West-Flanders (NW-Flanders), southern East-Flanders (SE-Flanders), southern Brabant (S-Brabant) and southern Limburg (S-Limburg); the black points are the selected communities with Oudenburg (O), Snellegem (S), Velzeke (V), Idegem (I), Alken (A) and Tongeren (T).

Figure 2

Rarefaction curves of the Y-chromosomal diversity of (a) three regions (NW-Flanders, SE-Flanders and S-Limburg) and all six selected communities, and (b) all four defined regions (NW-Flanders, SE-Flanders, S-Brabant, S-Limburg) inclusive of the six communities.

Figure 3

Principal component analysis (PCA) plot of the six communal samples based on the Y-chromosomal diversity together with a biplot; cumulative proportion is 0.74 for the first two principal components (PC1: 0.61; PC2: 0.13).

Figure 4

Correspondence analysis (CA) of the six communal samples based on the Y-chromosomal diversity (without unique sub-haplogroups).