Skin deep

The decoupling of genetic admixture levels from phenotypes that differed between source populations

Datos Bibliográficos

ID8315181
AutoresJaehee Kim (0000-0002-5210-2004, Department of Biology Stanford University Stanford California USA), Michael D Edge (0000-0001-8773-2906, Department of Biological Sciences University of Southern California Los Angeles California USA), Amy Goldberg (0000-0001-9306-1539, Department of Evolutionary Anthropology Duke University Durham North Carolina USA), Noah A Rosenberg (0000-0002-1829-8664, Department of Biology Stanford University Stanford California USA, autor de correspondencia)
Año2021
Volumen175
Número2
Páginas406-421
Fecha de publicación2021-06-01
Peer ReviewedSí
Open AccessSí
TipoARTICLE
RevistaAmerican Journal of Physical Anthropology (JOURNAL)
Identificadores de la revistaISSN: 0002-9483 • E-ISSN: 1096-8644
EditorialWiley (PUBLISHER • GB)
DOI10.1002/ajpa.24261
PMID33772750
OpenAlexW3151682550
IdiomaEN
Citas recibidas1
Referencias citadas51

OBJECTIVES: In genetic admixture processes, source groups for an admixed population possess distinct patterns of genotype and phenotype at the onset of admixture. Particularly in the context of recent and ongoing admixture, such differences are sometimes taken to serve as markers of ancestry for individuals-that is, phenotypes initially associated with the ancestral background in one source population are assumed to continue to reflect ancestry in that population. Such phenotypes might possess ongoing significance in social categorizations of individuals, owing in part to perceived continuing correlations with ancestry. However, genotypes or phenotypes initially associated with ancestry in one specific source population have been seen to decouple from overall admixture levels, so that they no longer serve as proxies for genetic ancestry. Here, we aim to develop an understanding of the joint dynamics of admixture levels and phenotype distributions in an admixed population. METHODS: We devise a mechanistic model, consisting of an admixture model, a quantitative trait model, and a mating model. We analyze the behavior of the mechanistic model in relation to the model parameters. RESULTS: We find that it is possible for the decoupling of genetic ancestry and phenotype to proceed quickly, and that it occurs faster if the phenotype is driven by fewer loci. Positive assortative mating attenuates the process of dissociation relative to a scenario in which mating is random with respect to genetic admixture and with respect to phenotype. CONCLUSIONS: The mechanistic framework suggests that in an admixed population, a trait that initially differed between source populations might serve as a reliable proxy for ancestry for only a short time, especially if the trait is determined by few loci. It follows that a social categorization based on such a trait is increasingly uninformative about genetic ancestry and about other traits that differed between source populations at the onset of admixture

Ancestry-informative marker · Assortative mating · Biology · Context (archaeology) · Evolutionary biology · Gene · Genetic admixture · Genetic genealogy · Genetic model · Genotype · Mating · Phenotype · Population · Single-nucleotide polymorphism · Trait · Demography · Evolutionary Psychology and Human Behavior · Forensic and Genetic Research · Genetics · Race, Genetics, and Society