Evidence-based policies that foster sustainability require both better statistics and a more realistic picture of modern-day seafood production dynamics.
Image credit: Allison Horst (University of California, Santa Barbara, CA).
New Research In
Physical Sciences
Featured Portals
Articles by Topic
Biological Sciences
Featured Portals
Articles by Topic
Edited by Mary-Claire King, University of Washington, Seattle, WA and approved November 19, 2009(received for review August 25, 2009)
↵1S.A.T. and C.D.B. contributed equally to this work.
Abstract
Quantifying patterns of population structure in Africans and African Americans illuminates the history of human populations and is critical for undertaking medical genomic studies on a global scale. To obtain a fine-scale genome-wide perspective of ancestry, we analyze Affymetrix GeneChip 500K genotype data from African Americans (n = 365) and individuals with ancestry from West Africa (n = 203 from 12 populations) and Europe (n = 400 from 42 countries). We find that population structure within the West African sample reflects primarily language and secondarily geographical distance, echoing the Bantu expansion. Among African Americans, analysis of genomic admixture by a principal component-based approach indicates that the median proportion of European ancestry is 18.5% (25th–75th percentiles: 11.6–27.7%), with very large variation among individuals. In the African-American sample as a whole, few autosomal regions showed exceptionally high or low mean African ancestry, but the X chromosome showed elevated levels of African ancestry, consistent with a sex-biased pattern of gene flow with an excess of European male and African female ancestry. We also find that genomic profiles of individual African Americans afford personalized ancestry reconstructions differentiating ancient vs. recent European and African ancestry. Finally, patterns of genetic similarity among inferred African segments of African-American genomes and genomes of contemporary African populations included in this study suggest African ancestry is most similar to non-Bantu Niger-Kordofanian-speaking populations, consistent with historical documents of the African Diaspora and trans-Atlantic slave trade.
Footnotes
- 2To whom correspondence may be addressed at: Departments of Biology and Genetics, 428 Clinical Research Building, 415 Curie Boulevard, University of Pennsylvania, Philadelphia, PA 19104–6145. E-mail: tishkoff{at}mail.med.upenn.edu.
- 3To whom correspondence may be addressed at: Department of Biological Statistics, Computational Biology, 102J Weill Hall, Cornell University, Ithaca, NY 14853. E-mail: cdb28{at}cornell.edu.
Author contributions: K.B., S.A.T., and C.D.B. designed research; K.B., A.A., S.A.T., and C.D.B. performed research; K.B., M.R.N., J.R.O., S.L.H., S.W., A.F., J.-M.B., C.W., S.A.T., and C.D.B. contributed new reagents/analytic tools; K.B., A.A., M.R.N., S.A.T., and C.D.B. analyzed data; K.B., A.A., S.A.T., and C.D.B. wrote the paper; and S.A.T. and C.D.B. co-supervised the project.
Conflict of interest statement: The authors declare no conflict of interest.
This article is a PNAS Direct Submission.
This article contains supporting information online at www.pnas.org/cgi/content/full/0909559107/DCSupplemental.
Freely available online through the PNAS open access option.
Genome-wide patterns of population structure and admixture in West Africans and African Americans
Sign up for Article Alerts
Jump to section
You May Also be Interested in
Previous research has suggested that women tend to be more risk-averse than men, but a study suggests that gender differences in risk preferences are shaped by culture and can be influenced by the environment.
Image courtesy of Pixabay/Clker-Free-Vector-Images.
Researchers report an electrode for electrolysis of seawater to hydrogen and oxygen that could be used in conjunction with solar cells to convert solar energy into hydrogen and oxygen without the need for desalination.
Image courtesy of Pixabay/Pexels.
A study of ancient urban trash mounds in the Byzantine settlement of Elusa in the Negev Desert of the southern Levant suggests a link between climate change and Late Antique urban collapse.
Image courtesy of Guy Bar-Oz.
PNAS Profile of NAS member and cancer biologist Daniel Haber
Image courtesy of Mark Karlsberg (Studio Eleven, Newton, MA).
More Articles of This Classification
Biological Sciences
Related Content
Cited by...
- Extreme genetic signatures of local adaptation during plant colonization
- Standardized biogeographic grouping system for annotating populations in pharmacogenetic research
- Population histories of the United States revealed through fine-scale migration and haplotype analysis
- Local PCA Shows How the Effect of Population Structure Differs Along the Genome
- Can secondary contact following range expansion be distinguished from barriers to gene flow?
- Cryptic Native American ancestry recapitulates population-specific migration and settlement of the continental United States
- Genetic landscapes reveal how human genetic diversity aligns with geography
- Evidence of population specific selection inferred from 289 genome sequences of Nilo-Saharan and Niger-Congo linguistic groups in Africa
- Identifying outlier loci in admixed and in continuous populations using ancestral population differentiation statistics
- Population genetic history and polygenic risk biases in 1000 Genomes populations
- pong: fast analysis and visualization of latent clusters in population genetic data
- Genome-wide evidence for a hybrid origin of modern polar bears
- The genetic ancestry of African, Latino, and European Americans across the United States
- Extensions of BLUP Models for Genomic Prediction in Heterogeneous Populations: Application in a Diverse Switchgrass Sample
- Cancer classification in the genomic era: five contemporary problems
- Detecting Heterogeneity in Population Structure Across the Genome in Admixed Populations
- Accounting for eXentricities: Analysis of the X chromosome in GWAS reveals X-linked genes implicated in autoimmune diseases
- Beyond 2/3 and 1/3: the complex signatures of sex-biased admixture on the X chromosome
- Local PCA Shows How the Effect of Population Structure Differs Along the Genome
- Genotype Imputation with Thousands of Genomes
- A Comparative Analysis of Genetic Ancestry and Admixture in the Colombian Populations of Choco and Medellin
- Dispersals and genetic adaptation of Bantu-speaking populations in Africa and North America
- Living in an adaptive world: Genomic dissection of the genus Homo and its immune response
- Breast Cancer and African Ancestry: Lessons Learned at the 10-Year Anniversary of the Ghana-Michigan Research Partnership and International Breast Registry
- A Genealogical Look at Shared Ancestry on the X Chromosome
- Detecting Heterogeneity in Population Structure Across the Genome in Admixed Populations
- Whole-exome sequencing to analyze population structure, parental inbreeding, and familial linkage
- Socioeconomic Position, But Not African Genomic Ancestry, Is Associated With Blood Pressure in the Bambui-Epigen (Brazil) Cohort Study of Aging
- Leukocyte Cell-Derived Chemotaxin 2-Associated Amyloidosis: A Recently Recognized Disease with Distinct Clinicopathologic Characteristics
- Genetic structure in village dogs reveals a Central Asian domestication origin
- Sympatric speciation revealed by genome-wide divergence in the blind mole rat Spalax
- Beyond 2/3 and 1/3: The Complex Signatures of Sex-Biased Admixture on the X Chromosome
- Origin and dynamics of admixture in Brazilians and its effect on the pattern of deleterious mutations
- Effect of Genetic African Ancestry on eGFR and Kidney Disease
- Reconstructing Past Admixture Processes from Local Genomic Ancestry Using Wavelet Transformation
- Genome-wide ancestry of 17th-century enslaved Africans from the Caribbean
- Autosomal Admixture Levels Are Informative About Sex Bias in Admixed Populations
- Genomics: A potential panacea for the perennial problem
- Genetic Variation and Adaptation in Africa: Implications for Human Evolution and Disease
- The Lengths of Admixture Tracts
- Genome-wide data substantiate Holocene gene flow from India to Australia
- Polar and brown bear genomes reveal ancient admixture and demographic footprints of past climate change
- Appetite regulation genes are associated with body mass index in black South African adolescents: a genetic association study
- Genome-wide detection of natural selection in African Americans pre- and post-admixture
- Combining Markers into Haplotypes Can Improve Population Structure Inference
- A General Mechanistic Model for Admixture Histories of Hybrid Populations
- Distribution of Parental Genome Blocks in Recombinant Inbred Lines
- Coalescence-Time Distributions in a Serial Founder Model of Human Evolutionary History
- Racial/Ethnic Variation in the Association of Lipid-Related Genetic Variants With Blood Lipids in the US Adult Population
- Replication of Breast Cancer GWAS Susceptibility Loci in the Women's Health Initiative African American SHARe Study
- Hunter-gatherer genomic diversity suggests a southern African origin for modern humans
- Detecting Directional Selection in the Presence of Recent Admixture in African-Americans
- The Effect of Recent Admixture on Inference of Ancient Human Population History
- Working toward a synthesis of archaeological, linguistic, and genetic data for inferring African population history
- Genome-wide patterns of population structure and admixture among Hispanic/Latino populations
- Genetic Structure in African Populations: Implications for Human Demographic History