Pigmentation shows a tremendous amount of variation in human populations, most probably due to the action of natural selection (e.g. skin pigmentation has been key for humans to adapt to different patterns of ultraviolet radiation). One of the major goals of my research has been to elucidate the genetic architecture of pigmentary traits (skin pigmentation, hair and eye colour) and the evolutionary factors that have shaped the current distribution of these complex traits in our species. I have participated in a large number of studies focused on different aspects of this topic, including: 1) Identification of genetic markers associated with pigmentary traits using genome-wide association approaches, 2) Development of novel methods to measure quantitatively skin pigmentation, hair and iris colour and 3) Detection of pigmentary genes that have been under positive selection in different population groups, and estimation of the timing of these selective events. Many of my studies have been carried out in non-European populations (East Asia, South Asia, the Americas), which have not been broadly surveyed, leaving an important gap in our understanding of the phenotypic and genetic variation in these traits. Unfortunately, pigmentary traits have been (and still are) used in typological classifications that fail to capture the diversity of our species. Because pigmentary traits have been under strong natural selection, the variation observed in these traits cannot be extrapolated to most other human traits, and this is an important message that I have tried to convey in my research and outreach activities (Parra EJ. 2007. American Journal of Biological Anthropology 134 (S45):85-105). Please, check my Publications link for more comprehensive information on my research in this field.