Sexual dimorphism: Asymmetry and diversity of 38 dermatoglyphic traits in five endogamous populations of West Bengal, India

Five hundred families from five different endogamous populations encompass the main social rank in the caste hierarchy of West Bengal, India were anal yzed for the present report. With the aim of comparing dermatoglyphic sexua l dimorphism among the groups, analysis of variance and principal component analysis were performed, based on 38 dermatoglyphic variables. Sex dimorph ism is homogeneous in nature in, all populations, indicating common charact eristics of dermatoglyphic variables within the same geographic area. But s ex differences display different levels when compared with other racial gro ups. Therefore, sex differences are different in diverse populations. This would explain the existence of the possible role of environmental prenatal factors in the realization of the Level of dermatoglyphic sex differences. Sex differences in asymmetry indices are Less pronounced, which indicates t hat Indian populations are less asymmetric compared to Jewish populations. Fluctuating asymmetry, which is greater in females compared to males, suppo rt the hypothesis of Livshits and Kobyliansky(1) - "increased heterozygosit y is often associated with a decreased phenotypic variability including a d iminished fluctuating asynmetry". A common feature of the principal compone nt factor 1 "digital pattern size factor", in diverse populations indicates its degree of universality, and suggests that the variability of finger ri dge counts is determined by the same genes which control the pattern types. The factors,,finger ridge count diversity factor", "directional asymmetry factor" fluctuating asymmetry factor", and "bilateral asymmetry factor" was perhaps described in the literature for the first time in Indian populatio ns. The nature of variation of these components among these populations and between, sexes, appears with a good similarity which suggests their biolog ical validity of the underlying component structure. The overall homogeneit y of sex dimorphism among 5 populations is well pronounced.