Quantitative dermatoglyphics and population structure in Northwest India

Area of Science:

• Anthropology
• Human Genetics
• Forensic Science

Background:

• Dermatoglyphics, the study of skin patterns, offers insights into human population variation.
• Northwest India presents a diverse ethnic and socioeconomic landscape, ideal for studying population genetics.

Purpose of the Study:

• To analyze dermatoglyphic variation across 12 endogamous populations in northwest India.
• To compare dermatoglyphic patterns with existing genetic marker data.
• To investigate population relationships and gene flow using quantitative dermatoglyphic variables.

Main Methods:

• Utilized 28 quantitative dermatoglyphic variables (20 finger ridge counts, 8 palmar pattern ridge counts).
• Applied multiple discriminant analysis and R-matrix analysis for population discrimination and gene flow inference.
• Reanalyzed published genetic marker data for comparative evaluation.

Main Results:

• Significant dermatoglyphic discrimination was found among northwestern Indian groups using both finger and palmar variables.
• Palmar variables contributed minimally to the explained variation compared to finger ridge counts.
• Population homogeneity varied, with Punjab showing the most homogeneity and Himachal Pradesh the most heterogeneity.
• Dermatoglyphic differentiation levels were comparable to those observed for genetic markers.
• Gene flow patterns inferred from dermatoglyphs aligned with population structure, though genetic markers provided a more realistic view.
• Dermatoglyphs reflected geographic patterns more than ethnic resemblance, while genetic markers showed the reverse.

Conclusions:

• Dermatoglyphic and genetic marker data reveal consistent patterns of population structure in northwest India.
• Geographic proximity influences dermatoglyphic variation more than ethnic relatedness.
• Genetic markers offer a more nuanced perspective on population history and gene flow.