Finger patterns characteristics as determinants of total ridge count variability

Abstract

The total ridge count (TRC) was viewed as a common composite trait with definite correlations between its components — the ridge counts (RC) of individual fingers. The TRC variability was accordingly examined as a function of the variability of these components. The distribution of pattern types on the fingers, the RC of patterns per total as well as per finger location, and the mean finger RC were all analyzed in relation to the RC variability and to a newly described phenomenon — the mutual influence on the RC variability of different patterns present concomitantly in an individual. It was concluded that the TRC variability is conditioned by the frequencies of the same genes which are responsible for the presence of the different finger pattern types. A high negative correlation coefficient, −0.901, was found between the pattern intensity index (PII) and the coefficient of variation of the TRC. The linear regression equation was: CV=90.75−4.20 PII. Biological isolation and the ensuing consanguinity may affect the TRC variability of a population by modifying the frequencies of these genes. This influence may be a decreasing as well as an increasing one. In contrast, when a common metric trait which is determined by additive genes without any dominance (as the TRC is frequently believed to be) is subjects to consanguinization effects, only a decrease in the variation is expected. The dermatoglyphics of 625 Jewish males were investigated and the general character of some dermatoglyphic regularities and trends was compared with and corroborated by data from the literature.