Gene-geographic analysis of a subdivided population: 2. Geography of random inbreeding based on surname frequencies in Adygs

An important characteristic of the genetic structure of populations, random inbreeding (interpopulation variation), was evaluated on the basis of quas i-genetic markers (surnames). The following methodological issues are consi dered: estimation of random inbreeding using the coefficient of isonymy f(r ) in a subdivided population, a comparison of inbreeding levels calculated on the basis of surname frequencies using f(r) and Wright's F-ST, a compari son of inbreeding estimates obtained on the basis of surnames and genetic m arkers, inbreeding variation in populations of the same hierarchical rank, and planning of genetic studies of a subdivided population. The population of Adygs (an indigenous ethnic group of Northern Caucasus) was examined as a model subdivided population. The population system of Adygs is hierarchic al. Parameters of random inbreeding were examined at each level of the syst em "ethnic group double right arrow tribe double right arrow geographic gro up of auls double right arrow aul." Frequencies of surnames were collected subtotally. Data on frequencies of 1340 surnames in 61 auls representing al l Adyg tribes were analyzed. In total, 60000 people were examined. The inbr eeding estimates obtained on the basis of Wright's F-ST and the coefficient of isonymy (f) over bar(r) virtually coincided: for Adygs in general, F-ST x 10(2) = 2.13 and (f) over bar(r) x 10(2) = 2.09. At the same time, the i nbreeding level exhibited marked differences among tribes: in Shapsugs, the se differences were an order of magnitude higher than in Kabardins ((f) ove r bar(r) x 10(2) = 2.53 and 0.25, respectively). The inbreeding estimates f or auls differed by two orders of magnitudes: (f) over bar(r) x 10(2) = 0.0 7 and (f) over bar(r) x 10(2) = 7.88. An analysis of ten auls yielded fully coinciding inbreeding estimates based on quasi-genetic ((f) over bar(r) x 10(2) = 0.60) and classical (F-ST = 0.69) gene markers. Computer maps of su rname distributions in Adygs (1340 maps) were constructed for the first tim e ever. Based on these maps, the map of random inbreeding in the Adyg popul ation was obtained.