Ethiopia: between Sub‐Saharan Africa and Western Eurasia

Abstract

Summary Ethiopia is central to population genetic studies investigating the out of Africa expansion of modern humans, as shown by Y chromosome and mtDNA studies. To address the level of genetic differentiation within Ethiopia, and its relationship to Sub‐Saharan Africa and Eurasia, we studied an 8kb segment of the X‐chromosome from 72 chromosomes from the Amhara, Oromo and Ethiopian Jews, and compared these results with 804 chromosomes from Middle Eastern, African, Asian and European populations, and 22 newly typed Saharawi. Within Ethiopia the two largest ethnic groups, the Amhara and Oromo, were not found to be statistically distinct, based on an exact test of haplotype frequencies. The Ethiopian Jews appear as an admixed population, possibly of Jewish origin, though the data remain equivocal. There is evidence of a close relationship between Ethiopian and Yemenite Jews, likely a result of indirect gene flow. Within an African and Eurasian context, the distribution of alleles of a variable Tn repeat, and the spread of haplotypes containing Africa‐specific alleles, provide evidence of a genetic continuity from Sub‐Saharan Africa to the Near East, and furthermore suggest that a bottleneck occurred in Ethiopia associated with an out of Africa expansion. Ethiopian genetic heterogeneity, as evidenced by principal component analysis of haplotype frequencies, most likely resulted from periods of subsequent admixture. While these results are from the analysis of one locus, we feel that in association with data from other marker systems they add a complementary perspective on the history of Ethiopia.

Identification of population substructure among Jews using STR markers and dependence on reference populations included

“…We found that, in many cases, evidence of admixture with host populations based on our autosomal data confirmed the results of previous mtDNA or Y-chromosome studies [6,20,22,23,40] (Fig. 2 and table 2).…”

Identification of population substructure among Jews using STR markers and dependence on reference populations included

“…We found that, in many cases, evidence of admixture with host populations based on our autosomal data confirmed the results of previous mtDNA or Y-chromosome studies [6,20,22,23,40] (Fig. 2 and table 2).…”

Identification and characterization of HIV positive Ethiopian elite controllers in both Africa and Israel

“…The rate of ECs was 0.6% for the General Ethiopian‐Israeli cohort and 0.16% for the General Mekelle cohort ( P = 0.011). This statistically significant difference could not be explained by genetic differences between Mekelle Ethiopians and Ethiopian immigrants to Israel, as great similarity in the genetics of Beta Israel Ethiopian Jews and local Ethiopians was described previously ; neither could it be explained by the longer follow‐up of EC patients in the Israeli cohort. The most likely explanation for the difference is a screening bias which originated from the Israeli policy of mandatory screening of all immigrants to Israel for HIV.…”

Bayesian phylogenetic analysis of Semitic languages identifies an Early Bronze Age origin of Semitic in the Near East

“…The simultaneous divergences of many Ethiosemitic subgroups and their current widespread distribution throughout Ethiopia suggest that Ethiosemitic underwent a rapid process of diversification and expansion upon arrival in Africa. Studies have shown that Ethiosemitic-speaking populations are genetically similar to Cushitic-speaking populations within Eritrea and Ethiopia (Lovell et al 2005). Thus, we propose that the current distribution of Ethiosemitic reflects a process of language diffusion through existing African populations with little gene flow from the Arabian Peninsula (i.e.…”

Identification of population substructure among Jews using STR markers and dependence on reference populations included

“…We found that, in many cases, evidence of admixture with host populations based on our autosomal data confirmed the results of previous mtDNA or Y-chromosome studies [6,20,22,23,40] (Fig. 2 and table 2).…”

Identification and characterization of HIV positive Ethiopian elite controllers in both Africa and Israel

“…The rate of ECs was 0.6% for the General Ethiopian‐Israeli cohort and 0.16% for the General Mekelle cohort ( P = 0.011). This statistically significant difference could not be explained by genetic differences between Mekelle Ethiopians and Ethiopian immigrants to Israel, as great similarity in the genetics of Beta Israel Ethiopian Jews and local Ethiopians was described previously ; neither could it be explained by the longer follow‐up of EC patients in the Israeli cohort. The most likely explanation for the difference is a screening bias which originated from the Israeli policy of mandatory screening of all immigrants to Israel for HIV.…”

Bayesian phylogenetic analysis of Semitic languages identifies an Early Bronze Age origin of Semitic in the Near East

“…The simultaneous divergences of many Ethiosemitic subgroups and their current widespread distribution throughout Ethiopia suggest that Ethiosemitic underwent a rapid process of diversification and expansion upon arrival in Africa. Studies have shown that Ethiosemitic-speaking populations are genetically similar to Cushitic-speaking populations within Eritrea and Ethiopia (Lovell et al 2005). Thus, we propose that the current distribution of Ethiosemitic reflects a process of language diffusion through existing African populations with little gene flow from the Arabian Peninsula (i.e.…”

Identification of population substructure among Jews using STR markers and dependence on reference populations included

“…We found that, in many cases, evidence of admixture with host populations based on our autosomal data confirmed the results of previous mtDNA or Y-chromosome studies [6,20,22,23,40] (Fig. 2 and table 2).…”

Identification and characterization of HIV positive Ethiopian elite controllers in both Africa and Israel

“…The rate of ECs was 0.6% for the General Ethiopian‐Israeli cohort and 0.16% for the General Mekelle cohort ( P = 0.011). This statistically significant difference could not be explained by genetic differences between Mekelle Ethiopians and Ethiopian immigrants to Israel, as great similarity in the genetics of Beta Israel Ethiopian Jews and local Ethiopians was described previously ; neither could it be explained by the longer follow‐up of EC patients in the Israeli cohort. The most likely explanation for the difference is a screening bias which originated from the Israeli policy of mandatory screening of all immigrants to Israel for HIV.…”

Bayesian phylogenetic analysis of Semitic languages identifies an Early Bronze Age origin of Semitic in the Near East

“…The simultaneous divergences of many Ethiosemitic subgroups and their current widespread distribution throughout Ethiopia suggest that Ethiosemitic underwent a rapid process of diversification and expansion upon arrival in Africa. Studies have shown that Ethiosemitic-speaking populations are genetically similar to Cushitic-speaking populations within Eritrea and Ethiopia (Lovell et al 2005). Thus, we propose that the current distribution of Ethiosemitic reflects a process of language diffusion through existing African populations with little gene flow from the Arabian Peninsula (i.e.…”