The genetic structure and history of Africans and African Americans.
Africa is the source of all modern humans, but characterization of genetic variation and of relationships among populations across the continent has been enigmatic. We studied 121 African populations, four African American populations, and 60 non-African populations for patterns of variation at 1327 nuclear microsatellite and insertion/deletion markers. We identified 14 ancestral population clusters in Africa that correlate with self-described ethnicity and shared cultural and/or linguistic properties. We observed high levels of mixed ancestry in most populations, reflecting historical migration events across the continent. Our data also provide evidence for shared ancestry among geographically diverse hunter-gatherer populations (Khoesan speakers and Pygmies). The ancestry of African Americans is predominantly from Niger-Kordofanian (approximately 71%), European (approximately 13%), and other African (approximately 8%) populations, although admixture levels varied considerably among individuals. This study helps tease apart the complex evolutionary history of Africans and African Americans, aiding both anthropological and genetic epidemiologic studies.
Tishkoff
Sarah A
SA
Department of Biology, University of Maryland, College Park, MD 20742, USA. tishkoff@mail.med.upenn.edu
Reed
Floyd A
FA
Friedlaender
Françoise R
FR
Ehret
Christopher
C
Ranciaro
Alessia
A
Froment
Alain
A
Hirbo
Jibril B
JB
Awomoyi
Agnes A
AA
Bodo
Jean-Marie
JM
Doumbo
Ogobara
O
Ibrahim
Muntaser
M
Juma
Abdalla T
AT
Kotze
Maritha J
MJ
Lema
Godfrey
G
Moore
Jason H
JH
Mortensen
Holly
H
Nyambo
Thomas B
TB
Omar
Sabah A
SA
Powell
Kweli
K
Pretorius
Gideon S
GS
Smith
Michael W
MW
Thera
Mahamadou A
MA
Wambebe
Charles
C
Weber
James L
JL
Williams
Scott M
SM
D000349:Africa; D001741:Black or African American / Q000208:ethnology / Q000235:genetics*; D001499:Bayes Theorem; D044383:Black People / Q000208:ethnology / Q000235:genetics*; D016000:Cluster Analysis; D004641:Emigration and Immigration; D005006:Ethnicity / Q000235:genetics; D051456:Gene Flow; D014644:Genetic Variation; D005838:Genotype; D005843:Geography; D006801:Humans; D054643:INDEL Mutation; D007802:Language; D018895:Microsatellite Repeats; D010802:Phylogeny; D020641:Polymorphism, Single Nucleotide; D025341:Principal Component Analysis; D044469:Racial Groups / Q000235:genetics