Early Back-to-Africa Migration into the Horn of Africa

• DOI: 10.1371/journal.pgen.1004393
• Publication Date: 2014-06-12T22:51:43Z
• Authors: Jason A. Hodgson; Connie J. Mulligan; Ali Al-Meeri; Ryan L. Raaum
• Keywords: Somali; Genetic genealogy; Genetic admixture; Ancestry-informative marker; Population Genetics

Genetic studies have identified substantial non-African admixture in the Horn of Africa (HOA). In most recent genomic studies, this ancestry has been attributed to with Middle Eastern populations during last few thousand years. However, mitochondrial and Y chromosome data are suggestive earlier episodes admixture. To investigate further, we generated new genome-wide SNP for a Yemeni population sample merged these published genetic from HOA broad selection surrounding populations. We used multidimensional scaling ADMIXTURE methods an exploratory analysis develop hypotheses on structure These analyses suggested that there might be distinct, differentiated African ancestries HOA. After partitioning into origin segments, found support distinct (Ethiopic) (Ethio-Somali) The Ethiopic is tightly restricted likely represents autochthonous population. HOA, which primarily novel Ethio-Somali inferred component, significantly all neighboring North Africa, Levant, Arabia. admixed ethnic groups, shows little inter-individual variance within estimated diverged other by at least 23 ka, does not carry unique Arabian lactase persistence allele arose about 4 ka. Taking account mitochondrial, chromosome, paleoclimate, archaeological data, find time back-to-Africa migration pre-agricultural.