The names of Spain: a study of the isonymy structure of Spain

When genetic and surname analyses meet historical sources: The C56R mutation associated with factor XI deficiency as a marker of human migration during the Spanish Reconquista

The C56R mutation associated with factor XI deficiency has been first evidenced in individuals from the French Basque Country. Genetic investigations revealed that this mutation occurred about 5400 years ago as a founder effect in this zone. Other cases were subsequently described in Southwestern Europe. Noticeably a cluster of cases was evidenced in Yecla, a small city from the province of Murcia, in Southeastern Spain. In correlation with historical sources our genetic data and surname analysis argue for associating this mutation with the migration of people from Western Pyrenees (and more probably from the Navarra province) toward Southeastern Spain during the Reconquista period.

Identifying author heritage using surname data: An application for Russian surnames

This research article puts forward a method to identify the national heritage of authors based on the morphology of their surnames. Most studies in the field use variants of dictionary‐based surname methods to identify ethnic communities, an approach that suffers from methodological limitations. Using the public file of ORCID (Open Researcher and Contributor ID) identifiers in 2015, we developed a surname‐based identification method and applied it to infer Russian heritage from suffix‐based morphological regularities. The method was developed conceptually and tested in an undersampled control set. Identification based on surname morphology was then complemented by using first‐name data to eliminate false‐positive results. The method achieved 98% precision and 94% recall rates—superior to most other methods that use name data. The procedure can be adapted to identify the heritage of a variety of national groups with morphologically regular naming traditions. We elaborate on how the method can be employed to overcome long‐standing limitations of using name data in bibliometric datasets. This identification method can contribute to advancing research in scientific mobility and migration, patenting by certain groups, publishing and collaboration, transnational and scientific diaspora links, and the effects of diversity on the innovative performance of organizations, regions, and countries.

The structure and migration patterns of the population of Uruguay through isonymy

Surname distribution can be a useful tool for studying the genetic structure of a human population. In South America, the Uruguay population has traditionally been considered to be of European ancestry, despite its trihybrid origin, as proved through genetics. The aim of this study was to investigate the structure of the Uruguayan population, resulting from population movements and surname drift in the country. The distribution of the surnames of 2,501,774 people on the electoral register was studied in the nineteen departments of Uruguay. Multivariate approaches were used to estimate isonymic parameters. Isolation by Distance was measured by correlating isonymic and geographic distances. In the study sample, the most frequent surnames were consistently Spanish, reflecting the fact that the first immigration waves occurred before Uruguayan independence. Only a few surnames of Native origin were recorded. The effective surname number (α) for the entire country was 302, and the average for departments was 235.8 ± 19. Inbreeding estimates were lower in the south-west of the country and in the densely populated Montevideo area. Isonymic distances between departments were significantly correlated with linear geographic distance (p < 0.001) indicating continuously increasing surname distances up to 400 km. Surnames form clusters related to geographic regions affected by different historical processes. The isonymic structure of Uruguay shows a radiation towards the east and north, with short-range migration playing a major role, while the contribution of drift, considering the small variance of α, appears to be minor.

Regional surname affinity: A spatial network approach

Objective

We investigate surname affinities among areas of modern‐day China, by constructing a spatial network, and making community detection. It reports a geographical genealogy of the Chinese population that is result of population origins, historical migrations, and societal evolutions.

Materials and methods

We acquire data from the census records supplied by China's National Citizen Identity Information System, including the surname and regional information of 1.28 billion registered Chinese citizens. We propose a multilayer minimum spanning tree (MMST) to construct a spatial network based on the matrix of isonymic distances, which is often used to characterize the dissimilarity of surname structure among areas. We use the fast unfolding algorithm to detect network communities.

Results

We obtain a 10‐layer MMST network of 362 prefecture nodes and 3,610 edges derived from the matrix of the Euclidean distances among these areas. These prefectures are divided into eight groups in the spatial network via community detection. We measure the partition by comparing the inter‐distances and intra‐distances of the communities and obtain meaningful regional ethnicity classification.

Discussion

The visualization of the resulting communities on the map indicates that the prefectures in the same community are usually geographically adjacent. The formation of this partition is influenced by geographical factors, historic migrations, trade and economic factors, as well as isolation of culture and language. The MMST algorithm proves to be effective in geo‐genealogy and ethnicity classification for it retains essential information about surname affinity and highlights the geographical consanguinity of the population.

CHANGES IN THE GENETIC STRUCTURE OF A VALLEY IN THE PYRENEES (CATALONIA, SPAIN)

In some situations the use of isonymy is the best strategy for studying the genetic structure of a population and its biological history. In this study different population parameters were calculated for one of the most isolated valleys in the Pyrenees - the region of the Alta Ribagorça in Catalonia, Spain. Surnames from marriage records covering the continuous period from 1638 to 1988 were used. From 1950 onwards this region underwent important social, economic and biological changes related to the introduction of hydroelectric and mining industries, and the change from livestock farming to a society based on services. Two periods were analysed (1638-1950 and 1951-1988) allowing population changes that occurred in the region to be determined. The study focused on calculating the number of surnames by gender, diversity index (H), population sub-structure (RP-RPr)/RPr and inbreeding coefficient (F t) and detection of possible genetic barriers. The results demonstrate the importance that geography initially had in shaping the genetic structure of the population and how this was gradually replaced by other parameters such as roads or the social and economic importance of towns. An interesting phenomenon is that inbreeding has traditionally been associated with rural life, isolation and endogamy. However, for the Alta Ribagorça it was observed that in the second period, 1951-1988, inbreeding mainly depended on the composition of migrant groups and the reaction of the native population to the arrival of migrants from outside the region.

Footprints of middle ages kingdoms are still visible in the contemporary surname structure of Spain

To assess whether the present-day geographical variability of Spanish surnames mirrors historical phenomena occurred at the times of their introduction (13th-16th century), and to infer the possible effect of foreign immigration (about 11% of present-day) on the observed patterns of diversity, we have analyzed the frequency distribution of 33,753 unique surnames (tokens) occurring 51,419,788 times, according to the list of Spanish residents of the year 2008. Isonymy measures and surname distances have been computed for, and between, the 47 mainland Spanish provinces and compared to a numerical classification of corresponding language varieties spoken in Spain. The comparison of the two bootstrap consensus trees, representing surname and linguistic variability, suggests a similar picture; major clusters are located in the east (Aragón, Cataluña, Valencia), and in the north of the country (Asturias, Galicia, León). Remaining regions appear to be considerably homogeneous. We interpret this pattern as the long-lasting effect of the surname and linguistic normalization actively led by the Christian kingdoms of the north (Reigns of Castilla y León and Aragón) during and after the southwards reconquest (Reconquista) of the territories ruled by the Arabs from the 8th century to the late 15th century, that is when surnames became transmitted in a fixed way and when Castilian linguistic varieties became increasingly prestigious and spread out. The geography of contemporary surname and linguistic variability in Spain corresponds to the political geography at the end of the Middle-Ages. The synchronicity between surname adoption and the political and cultural effects of the Reconquista have permanently forged a Spanish identity that subsequent migrations, internal or external, did not deface.

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

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.

Random inbreeding, isonymy, and population isolates in Argentina

Population isolates are an important tool in identifying and mapping genes of Mendelian diseases and complex traits. The geographical identification of isolates represents a priority from a genetic and health care standpoint. The purpose of this study is to analyze the spatial distribution of consanguinity by random isonymy (F ST) in Argentina and its relationship with the isolates previously identified in the country. F ST was estimated from the surname distribution of 22.6 million electors registered for the year 2001 in the 24 provinces, 5 geographical regions, and 510 departments of the country. Statistically significant spatial clustering of F ST was determined using the SaTScan V5.1 software. F ST exhibited a marked regional and departamental variation, showing the highest values towards the North and West of Argentina. The clusters of high consanguinity by random isonymy followed the same distribution. Recognized Argentinean genetic isolates are mainly localized at the north of the country, in clusters of high inbreeding. Given the availability of listings of surnames in high-capacity storage devices for different countries, estimating F ST from them can provide information on inbreeding for all levels of administrative subdivisions, to be used as a demographic variable for the identification of isolates within the country for public health purposes.

Surnames in Honduras: A study of the population of Honduras through isonymy

In this work, we investigated surname distribution in 4,348,021 Honduran electors with the aim of detecting population structure through the study of isonymy in three administrative levels: the whole nation, the 18 departments, and the 298 municipalities. For each administrative level, we studied the surname effective number, α, the total inbreeding, FIT , the random inbreeding, FST , and the local inbreeding, FIS . Principal components analysis, multidimensional scaling, and cluster analysis were performed on Lasker's distance matrix to detect the direction of surname diffusion and for a graphic representation of the surname relationship between different locations. The values of FIT , FST , and FIS display a variation of random inbreeding between the administrative levels in the Honduras population, which is attributed to the "Prefecture effect." Multivariate analyses of department data identified two main clusters, one south-western and the second north-eastern, with the Bay Islands and the eastern Gracias a Dios out of the main clusters. The results suggest that currently the population structure of this country is the result of the joint action of short-range directional migration and drift, with drift dominating over migration, and that population diffusion may have taken place mainly in the NW-SE direction.

Mitochondrial diversity patterns and the Magdalenian resettlement of Europe: new insights from the edge of the Franco-Cantabrian refuge

Phylogeography of the mitochondrial lineages commonly found in Western Europe can be interpreted in the light of a postglacial resettlement of the continent. The center of this proposal lies in the Franco-Cantabrian glacial refuge, located in the northern Iberian Peninsula and Southwestern France. Recently, this interpretation has been confronted by the unexpected patterns of diversity found in some European haplogroups. To shed new lights on this issue, research on Iberian populations is crucial if events behind the actual genetics of the European continent are to be untangled. In this regard, the region of Asturias has not been extensively studied, despite its convoluted history with prolonged periods of isolation. As mitochondrial DNA is a kind of data that has been commonly used in human population genetics, we conducted a thorough regional study in which we collected buccal swabs from 429 individuals with confirmed Asturian ancestry. The joint analysis of these sequences with a large continent-wide database and previously published diversity patterns allowed us to discuss a new explanation for the population dynamics inside the Franco-Cantabrian area, based on range expansion theory. This approximation to previously contradictory findings has made them compatible with most proposals about the postglacial resettlement of Western Europe.

Genetics of population exchange along the historical Portuguese-Spanish border

The present analysis compares the distribution of surnames by means of spatial autocorrelation analysis in the Spain-Portugal border region. The Spanish National Institute of Statistics provides a database of surnames of residents in the western Spanish provinces of Zamora, Salamanca, Cáceres, Badajoz and Huelva. The Spanish and Portuguese patterns of surname distribution were established according to various geographic axes. The results obtained show a low diversity of surnames in this region - especially in the centre - which can be explained by the absence of any major geographic barriers, with the exception of the mountain ranges between hydrographic basins, and by the presence of traditional roads that have existed since Roman times. The latter have resulted in a constant migratory flow over short-median distances, which, as can be deduced from the surnames, fits two north/south territorial axes running parallel to the border between Spain and Portugal. The distribution patterns of Portuguese and Spanish surnames differ with regard to their frequencies in the five provinces studied, which can be attributed to their respective historical, economic and social conditions. It is concluded that the border delimiting these two countries has affected the migratory flow, thereby conditioning the demographic and genetic structure of the western Spanish regions.

A study of surnames in China through isonymy

The isonymy structure of 1.28 billion people registered in China's National Citizen Identity Information System was studied at the provincial, prefectural, and county administrative division levels. The isonymy was 0.026 for China as a whole. The average value of isonymy was 0.033 for the 30 provinces, 0.035 for the 334 prefectures, and 0.040 for the 2811 counties. The isonymy in China was much higher than in other countries. This finding may be partly explained by the low number of surnames in the Chinese language. Two regional features can be identified from the geographic distributions of isonymy. One feature is that the middle and lower reaches of the Yangtze River had the lowest values of isonymy at both the provincial and county levels. The second feature is that most counties with the highest values of isonymy were distributed in the provinces with high proportions of ethnic minorities. According to the dendrogram of surname distances, several clusters could be identified. Most provinces in a cluster were conterminous with one another. The one exception could be explained by demic migration called "braving the journey to the northeast of China." Isolation by distance could be detected because the correlation coefficients between Nei's distance and the geographic distances at the provincial, prefectural, and county levels were 0.64, 0.43, and 0.37, respectively. Human behaviors in Chinese history that may have caused these results have been discussed, including cultural origin, migration, residential patterns, and ethnic distribution.

Isonymic structure of the Argentine Northwest

Surname distribution may be used as a substitute for quantitative information on the genetic structure of human populations due to panmictic deviations. This study analysed the isonymic structure of the Argentine Northwest (ANW) populations. Surname distribution of 2,576,548 voters (year 2001) in the 117 departments of the region was analysed. Fisher's alpha and coefficient of random relationship by isonymy were estimated. A dendrogram of the 117 departments was constructed from the matrix of Euclidean distances. In general, alpha values found were lower than country averages, while kinship values were higher. Ten clusters were identified showing a spatial distribution closely related to geographic characteristics, means of communication, and location of economic activities of the region. The resulting pattern could be basically characterized by grouping the departments into two large clusters: (a) Those located in the centre of the region, which include the provincial capitals, presented greater diversity of surnames and a lower degree of kinship. (b) Those located in the regional periphery showed greater isolation and kinship. Isonymic parameters estimated agree with the demographic characteristics of populations, historical antecedents of population settlement and ANW geographic features.

Surnames in Siberia: a study of the population of Yakutia through isonymy

We studied the isonymic structure of the Republic of Sakha (Yakutia), in the Russian Federation, using the surname distributions of 491,259 citizens above 18 years registered as residents in 2002. These were distributed in 35 districts and 497 towns and settlements of the Republic. The number of different surnames was 44,625. Matrices of isonymic distances between the 35 districts were tested for correlation with the geographic distance between the population centers of gravity of the districts. We found that, for the whole of Yakutia, Nei's distance was correlated with geographic distance (r = 0.693 +/- 0.027). A dendrogram of the 35 districts was built from the distance matrix, using the UPGMA method. The clusters identified by the dendrogram correlate with the geographic position of the districts. The correlation of random inbreeding calculated from isonymy, F(ST), with latitude was positive and highly significant but weak (r = 0.23). So, inbreeding was highest in the Arctic districts, and lowest in the South. Average alpha for 497 towns was 107, for 35 districts it was 311, and for the Republic 433. The value of alpha was higher for Russian than for the local languages. The geographical distribution of alpha, high in the Center and South-East and lower in the North-West, is compatible with the settlement of groups of migrants moving from the South-East toward the center and the North of Yakutia. It is proposed that low-density demic diffusion of human populations results in high inbreeding and may have been a general phenomenon in the early phases of human radiations.

Surname study of suicide in Austria: differences in regional suicide rates correspond to the genetic structure of the population

OBJECTIVES

There is convergent evidence from adoption, family, geographical, immigrant, molecular genetic, twin and, most recently, surname studies of suicide for genetic contributions to suicide risk. Surnames carry information about genetic relatedness or distance and, in patrilineal surname systems, are a close substitute for Y-chromosome markers and haplotypes, since surname transmission is similar to the transmission of the nonrecombining part of the Y chromosome. This study investigated whether differences in regional suicide rates correspond to the genetic structure of the Austrian population.

METHODS

Differences in district-level standardized suicide rates 1988-94 between the five major surname regions identified for Austria were analyzed. The surname regions used in the analysis reflect the contemporary population structure and closely follow the natural borders found in the topography of Austria, less so its administrative division into nine states.

RESULTS

Surname region accounted for a significant (P < 0.001) and substantial (38%) portion of the variance in district-level suicide rates. Adjusting the suicide rates for a set of five social and economic indicators that are established ecological correlates of suicide prevalence (income, and rates of the divorced, unemployed, elderly and Roman Catholics) left the results essentially unchanged.

CONCLUSIONS

Regional differences in suicide rates within Austria correspond to the genetic structure of the population. The present evidence adds to related findings from geographical and surname studies of suicide that suggest a role for genetic risk factors for suicidal behavior. Genetic differences between subpopulations may partially account for the geography of suicide. Study limitations and directions for future research are discussed.

Surnames in Western Europe: A comparison of the subcontinental populations through isonymy

We studied the isonymic structure of Western Europe using the distributions of 26.2 million surnames in 8 countries, 125 regions and 2094 towns of the Subcontinent. We found that, for the whole of Western Europe, Nei's distance was correlated with geographic distance (r=0.610+/-0.009). It was observed that at long geographic distances the isonymyc distance stays below linearity and tends to become asymptotic, and this was attributed to long distance migration. A dendrogram of the125 regions was built and the clusters identified by the dendrogram are almost exactly coincident with the nations of the Subcontinent. Random inbreeding calculated from isonymy, F(ST), was highest in Spanish regions, and lowest in France. The geographical distribution of alpha in 2094 towns, high in the Center and East of the Subcontinent and lower in Spain, is compatible with the settlement of subsequent waves of migrants moving from the West and from the South toward the centre of the Continent. The present surname structure of Western Europe is strictly linked to local languages.

Migration matrices and surnames in populations with different isolation patterns: Val di Lima (Italian Apennines), Val di Sole (Italian Alps), and La Cabrera (Spain)

Biodemographic methods are widely used to infer the genetic structure of human populations. In this study, we revise and standardize the procedures required by the migration matrix model of Malécot ([1950] Ann Univ Lyon Sci [A] 13:37-60), testing it in large historical-demographic databases of 85 populations from three mountain valleys with different degrees of isolation: Val di Lima (Italian Apennines, 21 parishes), Val di Sole, (Italian Alps, 27 parishes), and La Cabrera (Spain, 37 parishes). An add-on package (Biodem) for the R program is proposed to perform all calculations. Results from migration matrices are compared with those obtained from isonymic relationships. Migration and isonymy matrices are derived from 22,781 marriage records. Matrices are analyzed using a nonlinear isolation-by-distance (IBD) model and multivariate techniques (multidimensional scaling, Procrustes rotation, and cluster analysis). Microdifferentiation levels (F(ST)) from the migration data agree with the observed inbreeding values: higher values are found in La Cabrera (F(ST) = 0.0082), the most isolated population; Val di Lima (F(ST) = 0.0015) and Val di Sole (F(ST) = 0.0012) have lower values due to the larger parish population sizes and greater mobility. Temporal changes of F(ST) and IBD are analyzed using the migration matrix approach. The populations show a marked decline in F(ST) values in time, together with increased population mobility and emigration rates. In all three valleys, marital migration and isonymy yield similar results, suggesting that geographic distance is the most important factor structuring the populations. However, isonymy shows a lower correlation with geographic distance than migration matrices do. This difference can be attributed to the differing sensitivity of the methods for past migration events, and to genetic drift.

Inbreeding and surnames: A projection into Easter Island's past

The population of Easter Island is one of the most interesting extant human communities due to its unique demographic history, its geographic isolation, and the development of an incomparable culture characterized by the towering "Moais" and its enigmatic writing. Following the colonization of its population by Polynesians from the Mangarevan Islands in the 5th century AD, the island remained isolated up until the middle of the 20th century. Under these conditions, with endogamy levels fluctuating between 61.04-96.54% and given such a small population, a high rate of inbreeding, and consequently, an elevated level of genetic relationships would be expected. Using data from church and civil records, we calculated the consanguinity of the population of Rapa Nui. The results of this analysis do not support the hypothesis of a high level of consanguinity (alpha = 0.00028 and F(t) = 0.0007, with F(r) = 0.00586 and F(n) = -0.00519), suggesting instead the existence of a strategy used to avoid marriage between close relatives. To explain these observations, the structure and exchange dynamics of the population were studied in the tribes, known locally as "Mata." The results of this analysis suggest a tendency toward the avoidance of inbreeding within tribes, in order to decrease the rate of endogamy in each group. This is consistent with ethnographic observations from the beginning of the 20th century that support the existence of strict regulations to prevent inbreeding between closely related individuals. Furthermore, we confirm that this situation dates back to a period before the "refounding" of Easter Island. Our results demonstrate that conditions of geographical isolation are not in themselves sufficient to produce an elevated inbreeding coefficient, revealing Easter Island as an interesting example of how cultural rules can shape the genetic structure of a population.

Surnames and dialects in France: population structure and cultural evolution

To study the isonymy structure of France as related to local language variations, the surname distributions of 6.03 million telephone users registered for the year 2002 were analysed in the 21 conterminous regions, their 94 departments and in 809 towns of the Country. For regions and departments the differences among local dialects were quantified according to the dialecto-metrization of the Atlas Linguistique Français. We found that Lasker's distance between regions was correlated with geographic distance with r=0.692+/-0.040, while Euclidean (r=0.546+/-0.058) and Nei's (r=0.610+/-0.048) distances were less correlated. Slightly lower correlations were observed for departments. Also, dialectometric distance was correlated with geography (r=0.582+/-0.069 for regions and r=0.617+/-0.015 for departments). The correlations between Lasker and dialectometric matrix distances for regions and departments are r=0.625+/-0.046 and 0.544+/-0.014, respectively, indicating that the common cause generating surname and language diversity accounts for about 35% of the differentiation. Both Lasker and dialectometric distances identify very similar boundaries between Poitou, Centre, Bourgogne and Franche Comptée at the North, and Aquitaine, Limousin, Auvergne, Rhône-Alpes in the South. Average Fisher's alpha for France was 7877 the highest value observed for the European countries studied to date. The size of alpha in most French towns indicates considerable recent immigration.

Surnames in Argentina: a population study through isonymy

In order to study the isonymic structure of Argentina, the surname distributions of 22.6 million electors registered for the year 2001 were analyzed in the 24 districts (distritos) and 541 municipalities (municipios) of the country. The number of different surnames found was 414,441. Matrices of isonymic distances between districts were constructed and tested for correlation with the geographic distance between the capital towns of the districts. We found that, for the whole of Argentina, Euclidean distance was correlated with the log of geographic distance (r=0.480+/- 0.067). A dendrogram of the 24 regions was built from the matrix of Euclidean distances, using the UPGMA method. The clusters identified by the dendrogram are coincident with conterminous geographical regions of the country. Random inbreeding calculated from isonymy, F(ST), was highest in La Rioja, Corrientes, and Santiago del Estero. It was lowest in the area of Buenos Aires and in the north-central region of Santa Fé. Average Fisher's alpha for municipalities was 358; for districts, it was 422; and for Argentina as a unit, it was 602. The geographical distribution of alpha in 541 municipalities, high in the east and lower in the west of the country, is compatible with the settlement in the 20th century of subsequent waves of immigrants moving from the North Atlantic coast toward the foot of the Andes and toward the south. The present structure of Argentina indicates that migration dominates over drift.