Surname and Y chromosome in Southern Europe: a case study with Colom/Colombo

Abstract

According to most historians, Christopher Columbus was born in Genoa, Italy. However, based on some key facts in the discoverer's biography, as well as in the linguistic analysis of his texts, some historians and linguists believe that Columbus could have been of Catalan origin. A Ligurian Columbus would have carried the Colombo surname, whereas he would have been called Colom if he were Catalan. In order to test whether it would be possible to discriminate between a Ligurian or a Catalan origin were Columbus' Y-chromosome haplotype to be retrieved, we genotyped 17 Y-chromosome STRs in 238 Spanish (from Catalonia, Valencia, and the Balearic Islands) and French Colom men, and 114 North Italian Colombo (from Liguria, Lombardy, and Piedmont). The Italian samples and, in particular, the Lombard Colombos were genetically as diverse as the general population, and we found little evidence of clusters of haplotypes that could indicate descent from a single founder. Colombo is actually the most frequent surname in Lombardy, where foundlings and orphans used to be given the surname Colombo. By contrast, Y-chromosome diversity was reduced in the Iberian Colom, where most of the men had Y chromosomes belonging to a few lineages. This implies that a positive identification would be more likely if Columbus were of Catalan descent. In this study, we have shown the diverse dynamics of two surnames linked by their etymology, in what is, to the best of our knowledge, the first genetic analysis of a surname in Southern Europe.

Figure 1

Populations and localities where Colom/Colombo men were sampled. Dot area is proportional to the number of individuals sampled in that locality.

Figure 2

(a) Multidimensional scaling plot based on F_ST distances among haplotypes. Stress was 1.4%. (b) MDS after removing the outlying Balearic Colom sample. Stress was 7.7%. Abbreviations: B, Balearic; C, Catalan; V, Valencian; FSE, SE French; FSW, SW French; LO, Lombard; LI, Ligurian; PI, Piedmontese; CTR, Catalan control sample; ITR, Northern Italian control sample.

Figure 3

Median joining networks for the Colom/Colombo chromosomes in each estimated haplogroup. Dotted ovals indicate lineages comprising more than one haplotype.

Figure 4

Median joining network for the estimated R1b chromosomes. Lineages comprising more than one haplotype are indicated with colored lines. Population color codes as in Figure 3.