title: Skin pigmentation variation among populations of West Maharashtra, India.
abstract: OBJECTIVE
  Global patterns of skin pigmentation have evolved as an adaptation to local ultraviolet radiation (UVR). Indian populations exposed to intense UVR show great variation in skin pigmentation. The UVR-based selection model cannot satisfactorily address the high prevalence of light skin among these populations. Thus, the present study examines pigmentation variation among populations of West Maharashtra and the Indian subcontinent within the context of population structure and social hierarchy.
  
  
  METHODS
  Melanin index (MI) was measured from 555 individuals representing six endogamous populations of West Maharashtra. Skin pigmentation was assessed in terms of variation between populations and differences between and among castes and tribes. A linear regression analysis was run to assess the relationship among MI, UVR, and social hierarchy using published MI data from 13 Indian endogamous populations.
  
  
  RESULTS
  Skin pigmentation differed significantly among populations of West Maharashtra. Significant pigmentation variation exists between castes and tribes of West Maharashtra as well as across the Indian subcontinent. We observe a significant negative relationship between social hierarchy and skin pigmentation, whereas the relationship between UVR and MI is weak.
  
  
  CONCLUSIONS
  Our results suggest that various factors may have contributed to pigmentation diversity across the Indian subcontinent. The lack of correlation between UVR and MI suggests that natural selection may not have played a significant role in shaping pigmentation variation across the subcontinent. We discuss other possible explanations, including metabolic conservation and cultural factors such as traditional social hierarchies and strict endogamy that have led to the development of population structure.
authors.affiliation: Department of Anthropology, Savitribai Phule Pune University, Pune, 411007, Maharashtra, India.
authors.forename: Manjari
authors.initials: M
authors.lastname: Jonnalagadda
authors.affiliation: Department of Anthropology, Savitribai Phule Pune University, Pune, 411007, Maharashtra, India.
authors.forename: Shantanu
authors.initials: S
authors.lastname: Ozarkar
authors.affiliation: Department of Zoology, Savitribai Phule Pune University, Pune, 411007, Maharashtra, India.
authors.forename: Richa
authors.initials: R
authors.lastname: Ashma
authors.affiliation: Department of Anthropology, Savitribai Phule Pune University, Pune, 411007, Maharashtra, India.
authors.forename: Shaunak
authors.initials: S
authors.lastname: Kulkarni
mesh_terms: D005260:Female; D006608:Hierarchy, Social; D006801:Humans; D007194:India; D008297:Male; D008393:Marriage; D012880:Skin Pigmentation; D014466:Ultraviolet Rays