Distribution of the number of heterozygous loci in the Kota population of Nilgiri Hills of India and estimation of average heterozygosity

From an electrophoretic survey of 17 protein enzyme loci in seven Kota villages of the Nilgiri Hills, Madras region of South India, the distribution of the number of heterozygous loci is computed. It is demonstrated that the mean of this distribution provides an alternative estimate of the average heterozygosity in an individual per locus which does not make use of the assumptions of linkage equilibrium and random mating. Since the Kotas practise a high degree of consanguineous marriages, this new estimate is suggested to be more appropriate for such isolated populations. Through an F_ST analysis it is shown that there is very little gene differentiation among the seven Kota villages where substantial gene migration occurs through inter-village marriages.