Biochemical heterozygosity as a predictor of developmental homeostasis in man

The relationships between the variability of 48 morphological traits and the heterozygosity of four blood group loci were studied in 200 Israeli Jewish males of Eastern European origin aged 18–22 years. A definite correlation was observed between the level of heterozygosity and the variability of 17 traits and two indices. Of the latter traits only 10 were chosen for further analysis. Principal component analysis showed that seven of these traits were independent. For six of them, the frequency of modal individuals (average ± 0·67 s.d.) in the tetraheterozygous group was the highest, diminishing proportionally with decreasing heterozygosity levels. The degree of heterozygosity also had a significant negative correlation with the coefficient of variation of the morphological characters and was positively associated with the kurtosis values. Only the variability of one of 10 traits showed an opposite trend and a correlation with biochemical homozygosity. The results are discussed in terms of developmental homeostasis.