BACKGROUND: Surnames are an easy tool to analyse human genetic structure, mobility and evolution. Few studies use surnames to estimate human migration at different geographical level. PRIMARY OBJECTIVE: Here we propose the application of a Bayesian method to estimate the probability of geographical origin (pgo) of migrants in a given area using surnames. METHOD: This method can be applied with data recordings when they are available for at least two successive periods and in the areas which are the potential sources of emigration. The principle is that the new surnames which are arriving during the second period in the area under investigation can provide information on their geographical origins. The probability of the origin of migrants can easily be estimated iteratively from the frequency of surnames by using the Bayes' theorem. RESULTS: This method is exemplified using civil birth registers at different geographical scales. The pgo of migrants, estimated between two periods (1891-1915 and 1916-1940), (i) from French departments to Paris (ii), from these departments to Tarbes, and (iii) from counties surrounding Tarbes to Tarbes, are mapped and discussed.

Bayes Theorem↗

PubMedDate not supplied

Segregation analysis of a-b ridge count in human palms.

Frequency distribution and segregation analyses have been performed on a-b ridge counts from 422 families. The results support the hypothesis of two commingled distributions of the trait, high-value distributions being 5.4% in females and 2.4% in males of the whole population. Segregation analyses point out evidence for simultaneously a multi-factorial inheritance (h = 0.72) and a major effect (P = 0.01). However, by testing different hypotheses on transmission laws for the major effect, we cannot decide between Mendelian transmission and no transmission. Hypothesis of an accident occurring in the developmental process of the a-b count has to be investigated further.

Dermatoglyphics↗

PubMedDate not supplied

Genealogical and genetical African admixture estimations, blood pressure and hypertension in a Caribbean community.

This study examines the relationships between blood pressure, prevalence of hypertension, and the degree of black African admixture in the population of the Caribbean Island of La Désirade which is homogeneous with respect to the environmental factors and for which the socioeconomical stratification does not match racial origin. The degree of admixture was estimated by using both genealogical information and genetic markers. Blood pressure was repeatedly measured using an automatic sphygmomanometer. After adjustment for age, sex, ponderal index, Na/K urinary ratio, and clinical alcoholism, blood pressure and prevalence of hypertension were found to be significantly higher for the individuals having the largest proportion of genes of black origin. Identical results were obtained when either genetic markers or genealogical information were used as an individual--estimator of admixture.

ABO Blood-Group System↗

PubMedDate not supplied

Relationships between consanguinity and migration rate from surname distributions and isonymy in France.

The distribution of surnames in France during the period 1916-40 is analysed from the civil birth registers for each of the 36,500 administrative units. The migration rate estimated from surnames is compared with the migration rate obtained from demographic census data. The correlations calculated among the 90 Departments ranges between 0.52 and 0.76 according to the size of the communes. Moreover, the migration rate is shown to be highly correlated with the average coefficient of consanguinity based on dispensations for marriages between relatives. These findings point to the validity and the usefulness of quantifying migrations on the basis of surname data and they show that migration flux and consanguinity are inversely and closely linked.

Consanguinity↗

PubMedDate not supplied

Surname distribution in France: a distance analysis by a distorted geographical map.

The distribution of surnames in 90 distinct regions in France during two successive periods, 1889-1915 and 1916-1940, is analysed from the civil birth registers of the 36,500 administrative units in France. A new approach, called 'Mobile Site Method' (MSM), is developed to allow representation of a surname distance matrix by a distorted geographical map. A surname distance matrix between the various regions in France is first calculated, then a distorted geographical map called the 'surname similarity map' is built up from the surname distances between regions. To interpret this map we draw (a) successive map contours obtained during the step-by-step distortion process, revealing zones of high surname dissimilarity, and (b) maps in grey levels representing the displacement magnitude, and allowing the segmentation of the geographical and surname maps into 'homogeneous surname zones'. By integrating geography and surname information in the same analysis, and by comparing results obtained for the two successive periods, the MSM approach produces convenient maps showing: (a) 'regionalism' of some peripheral populations such as Pays Basque, Alsace, Corsica and Brittany; (b) the presence of preferential axes of communications (Rhodanian corridor, Garonne valley); (c) barriers such as the Central Massif, Vosges; (d) the weak modifications of the distorted maps associated with the two periods studied suggest an extension (but limited) of the tendency of surname uniformity in France. These results are interpreted, in the nineteenth- and twentieth century context, as the consequences of a slow process of local migrations occurring over a long period of time.

France↗