GENETIC DIFFERENTIATION AND POPULATION-STRUCTURE OF SOME OCCUPATIONALCASTE GROUPS IN UTTAR-PRADESH, INDIA

Phenotypes and gene frequencies of 24 genetic markers (9 blood groups, 11 red cell enzymes, and 4 serum proteins) were investigated in 5 occ upational caste groups (Brahmin, Khatri, Vaish, Kayastha, and schedule d castes) and 1 religious group of Muslims in Uttar Pradesh, India, Th is is the first extensive genetic study in Uttar Pradesh that establis hes the range of genetic variation in different endogamous groups. The extent of genetic variation among different occupational caste groups is low, and only two genetic systems (C3 and ACP) showed heterogeneit y. The genetic affinity analysis showed an unexpected close affinity o f scheduled castes with the Khatri. This observation warrants further analysis of these groups, but the present results may be a chance find ing resulting from the nature of the samples, which represent individu als from vastly different regions of Uttar Pradesh. The affinity of th e Muslim group with other caste groups suggests that the samples may i nclude descendants of converts from the seventeenth century who are st ill at an early stage of differentiation. The F-ST estimate for the po pulations is 0.009, which is close to other estimates reported from no rth and northwest India, The overall mean F-IS value is 0.066, and for each locus the F-IS estimate is considerably higher than the F-ST est imate, suggesting that the infrastructure of the populations is influe nced by nonrandom mating (inbreeding). There is no evidence of any dis ruptive selection, but the allele frequency of each caste group of Utt ar Pradesh must be affected by its large population size, which, becau se of chance migration of individuals with different gene frequencies, would accentuate genetic differences.