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 analyzed for the present report. With the aim of comparing dermatoglyphic sexual dimorphism among the groups, analysis of variance and principal component analysis were performed, based on 38 dermatoglyphic variables. Sex dimorphism is homogeneous in nature in all populations, indicating common characteristics of dermatoglyphic variables within the same geographic area. But sex differences display different levels when compared with other racial groups. 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 that Indian populations are less asymmetric compared to Jewish populations. Fluctuating asymmetry, which is greater in females compared to males, support the hypothesis of Livshits and Kobyliansky--"increased heterozygosity is often associated with a decreased phenotypic variability including a diminished fluctuating asymmetry". A common feature of the principal component factor 1 "digital pattern size factor", in diverse populations indicates its degree of universality, and suggests that the variability of finger ridge 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 populations. The nature of variation of these components among these populations and between sexes, appears with a good similarity which suggests their biological validity of the underlying component structure. The overall homogeneity of sex dimorphism among 5 populations is well pronounced.
Karmakar
B
B
Anthropology and Human Genetics Unit, Indian Statistical Institute, Calcutta, India.
Yakovenko
K
K
Kobyliansky
E
E
D000328:Adult; D003878:Dermatoglyphics; D005260:Female; D006801:Humans; D007194:India; D008297:Male; D012727:Sex Characteristics; D012923:Social Class