Y-chromosome diversity in Catalan surname samples: insights into surname origin and frequency

Abstract

The biological behavior of the Y chromosome, which is paternally inherited, implies that males sharing the same surname may also share a similar Y chromosome. However, socio-cultural factors, such as polyphyletism, non-paternity, adoption, or matrilineal surname transmission, may prevent the joint transmission of the surname and the Y chromosome. By genotyping 17 Y-STRs and 68 SNPs in~2500 male samples that each carried one of the 50 selected Catalan surnames, we could determine sets of descendants of a common ancestor, the population of origin of the common ancestor, and the date when such a common ancestor lived. Haplotype diversity was positively correlated with surname frequency, that is, rarer surnames showed the strongest signals of coancestry. Introgression rates of Y chromosomes into a surname by non-paternity, adoption, and transmission of the maternal surname were estimated at 1.5 − 2.6% per generation, with some local variation. Average ages for the founders of the surnames were estimated at~500 years, suggesting a delay between the origin of surnames (twelfth and thirteenth centuries) and the systematization of their paternal transmission. We have found that, in general, a foreign etymology for a surname does not often result in a non-indigenous origin of surname founders; however, bearers of some surnames with an Arabic etymology show an excess of North African haplotypes. Finally, we estimate that surname prediction from a Y-chromosome haplotype, which may have interesting forensic applications, has a~60% sensitivity but a 17% false discovery rate.

People from Ibiza: an unexpected isolate in the Western Mediterranean

“…This is possibly due to the highly drifted Ibizan sample, and the high homogeneity among the mainland populations. In conclusion, our study suggests that the elevated genetic differentiation Ibizans have from other Spanish groups does not result from genetic continuity with Phoenician founders; also, the presence of more and longer ROH segments supports the hypothesis of increased parental relatedness due to the well recorded practice of consanguineous unions on the island, while the IBD chunks distribution supports the genetic drift and also suggests that a population collapse,10-15 generations ago, affected the island, likely corresponding to the bubonic plague occurred in 1652. by the MINECO (ref: MDM-2014-0370). SAB was supported by the Agencia Estatal de Investigación FPI grant BES-2014-069224.…”

“…In the plot (Figure 1), the first PC clearly separates all of the Ibizan samples from the rest of the Spanish subjects, while the second PC separates Basque samples from the rest, within which no structure can be discerned. Because PC1 and PC2 explain approximately the same proportion of variance 31 , these results imply that the genetic differentiation of Ibiza from the rest of Spain is at least of the same order of magnitude as that of the 10 Basque Country. When we narrowed the analysis down to 120 samples in the three core regions (Catalonia, Valencia, and the Balearic Islands) we still detected two separate clusters defined along the first PC ( Figure S3).…”

Group membership, geography and shared ancestry: Genetic variation in the Basotho of Lesotho

“…Common origin was also shown for individuals sharing the same surnames, the western societies version of patrilineally inherited social markers (Sol e-Morata et al, 2015;Martinez-Cadenas et al, 2016). Spanish and British (but not Irish) surnames showed a correlation between surname occurrence and genetic diversity: the more common a surname was, the less genetically homogenous its bearers were (McEvoy and Bradley, 2006;King and Jobling, 2009;Martinez-Cadenas et al, 2016).…”

High rate of extrapair paternity in a human population demonstrates diversity in human reproductive strategies

“…High-quality genetic evidence of EPP in humans has only begun to accumulate in the last 5 to 10 years and is focused almost exclusively on populations of European descent (12). Unlike the picture of variable rates of concurrency emphasized by anthropologists, genetic data from both contemporary and historical populations have consistently revealed very low rates of EPP (~1 to 2%) (13)(14)(15)(16)(17)(18)(19). The only modern study of paternity in a non-Western population, among the Dogon of Mali, shows a similar rate of 1.8% (20).…”