Jean Benoist

The ecological gradient of the weight/surface relationship among Israeli groups of various origin

Abstract The measurements of 1164 adult men in Israel show the existence of a geographic gradient of the weight/surface ratio, linked to the immigrants country of origin. Classed according to the increasing value of this relationship, the groups examined are situated as follows: Cochin, Yemen, Middle-Eastern, North Africans, Karaim, Europeans. The values of the relationship for Jews born in Israel are very close to those of the various parental groups, while the absolute value of the measurements is significantly higher. These facts would be difficult to explain were the differences observed to be attributed to phenotypic variations alone in the absence of any genetic support. On the contrary, the phenotypic adaptation reflected by the geographic gradient of the weight/surface ratio and the stability of the ratio among the descendants of the transplanted groups, implies that selection plays an important role.

Social values and population structure: Phenotype and genealogies in La Désirade (West Indies)

In a small population (La Désirade, West Indies) with few internal socio-economic differences, the «white» segment survive on the basis of long-term assortative mating. This study compares the genealogies for one hundred and forty years, with phenotypical markers used in the population to define «racial» identity of individuals. Physical appearance, acting as an isolated factor, is able to maintain endogamy and to ensure the survival of a segment of the population without any black admixture. The social values do not produce the same effect among people of African origin. Genetic structure reflects these values and the genealogical pattern is able to assert their impact on the mating pattern.