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Giovanni's new TEDx talk in Peru

Published: Oct 10, 2014 4:18:45 PM

Candela Introductory Paper

Published: Oct 5, 2014 4:01:05 PM

New PhD Fellow Javier Mendoza-Revilla

Published: Oct 5, 2014 4:00:57 PM

Introducing a CANDELA doctoral fellow

Published: Oct 5, 2014 4:00:44 PM

Candela Paper on Skin Pigmentation

Published: Oct 5, 2014 11:34:12 AM

South America Map

CANDELA - Consortium for the Analysis of the Diversity and Evolution of Latin America


We are an international, multidisciplinary consortium involving academic researchers studying the biological diversity of Latin Americans and its social context. We are currently focusing on individuals from five countries: Mexico, Colombia, Peru, Chile and Brazil. In these individuals we are performing a characterization of their physical appearance, examining their genetic make-up and social background, and evaluating their perception and attitudes regarding themselves and others. With this research we aim to probe a broad range of questions relevant to anthropological, biological and medical research. We also aim to explore the complex relationship between social and biological factors impinging on ideas about ethnic identity and race, and reflectively examine the motivations of biological research in Latin American populations.

Our work is supported by the academic institutions involved: the Leverhulme Trust, the Biotechnology and Biological Sciences Research Council.

Páginas em portugués      -      Páginas en español

CANDELA Introductory paper published in PLoS Genetics:

‘Admixture in Latin America: Geographic Structure, Phenotypic Diversity and Self-Perception of Ancestry Based on 7,342 Individuals’

Summary from the article:

Latin America has a history of extensive mixing between Native Americans and people arriving from Europe and Africa. As a result, individuals in the region have a highly heterogeneous genetic background and show great variation in physical appearance. Latin America offers an excellent opportunity to examine the genetic basis of the differentiation in physical appearance between Africans, Europeans and Native Americans. The region is also an advantageous setting in which to examine the interplay of genetic, physical and social factors in relation to ethnic/racial self-perception. Here we present the most extensive analysis of genetic ancestry, physical diversity and self-perception of ancestry yet conducted in Latin America. We find significant geographic variation in ancestry across the region, this variation being consistent with demographic history and census information. We show that genetic ancestry impacts many aspects of physical appearance. We observe that self-perception is highly influenced by physical appearance, and that variation in physical appearance biases self-perception of ancestry relative to genetically estimated ancestry.

Link: http://www.plosgenetics.org/doi/pgen.1004572

Citation:

Ruiz-Linares A, Adhikari K, Acuña-Alonzo V, Quinto-Sanchez M, Jaramillo C, et al. (2014) Admixture in Latin America: Geographic Structure, Phenotypic Diversity and Self-Perception of Ancestry Based on 7,342 Individuals. PLoS Genet 10(9): e1004572. doi:10.1371/journal.pgen.1004572

CANDELA paper on human skin pigmentation published in PLoS ONE:

`Implications of the Admixture Process in Skin Color Molecular Assessment’

Summary from the article:

The understanding of the complex genotype-phenotype architecture of human pigmentation has clear implications for the evolutionary history of humans, as well as for medical and forensic practices. Although dozens of genes have previously been associated with human skin color, knowledge about this trait remains incomplete. In particular, studies focusing on populations outside the European-North American axis are rare, and, until now, admixed populations have seldom been considered. The present study was designed to help fill this gap. Our objective was to evaluate possible associations of 18 single nucleotide polymorphisms (SNPs), located within nine genes, and one pseudogene with the Melanin Index (MI) in two admixed Brazilian populations (Gaucho, N = 352; Baiano, N = 148) with different histories of geographic and ethnic colonization. Of the total sample, four markers were found to be significantly associated with skin color, but only two (SLC24A5 rs1426654, and SLC45A2 rs16891982) were consistently associated with MI in both samples (Gaucho and Baiano). Therefore, only these 2 SNPs should be preliminarily considered to have forensic significance because they consistently showed the association independently of the admixture level of the populations studied. We do not discard that the other two markers (HERC2 rs1129038 and TYR rs1126809) might be also relevant to admixed samples, but additional studies are necessary to confirm the real importance of these markers for skin pigmentation. Finally, our study shows associations of some SNPs with MI in a modern Brazilian admixed sample, with possible applications in forensic genetics. Some classical genetic markers in Euro-North American populations are not associated with MI in our sample. Our results point out the relevance of considering population differences in selecting an appropriate set of SNPs as phenotype predictors in forensic practice.

Link: http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0096886

Citation:

Cerqueira CCSd, Hünemeier T, Gomez-Valdés J, Ramallo V, Volasko-Krause CD, et al. (2014) Implications of the Admixture Process in Skin Color Molecular Assessment. PLoS ONE 9(5): e96886. doi:10.1371/journal.pone.0096886


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