The episode of genetic drift defining the migration of humans out of Africa is derived from a large east African population size.
Human genetic variation particularly in Africa is still poorly understood. This is despite a consensus on the large African effective population size compared to populations from other continents. Based on sequencing of the mitochondrial Cytochrome C Oxidase subunit II (MT-CO2), and genome wide microsatellite data we observe evidence suggesting the effective size (Ne) of humans to be larger than the current estimates, with a foci of increased genetic diversity in east Africa, and a population size of east Africans being at least 2-6 fold larger than other populations. Both phylogenetic and network analysis indicate that east Africans possess more ancestral lineages in comparison to various continental populations placing them at the root of the human evolutionary tree. Our results also affirm east Africa as the likely spot from which migration towards Asia has taken place. The study reflects the spectacular level of sequence variation within east Africans in comparison to the global sample, and appeals for further studies that may contribute towards filling the existing gaps in the database. The implication of these data to current genomic research, as well as the need to carry out defined studies of human genetic variation that includes more African populations; particularly east Africans is paramount.
Department of Molecular Biology, Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan.
Nuha
N
Elhassan
Department of Molecular Biology, Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan; Department of Biology, Eritrea Institute of Technology, Mai-Nefhi, Eritrea.
Eyoab Iyasu
EI
Gebremeskel
Department of Molecular Biology, Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan.
Mohamed Ali
MA
Elnour
Department of Biochemistry, Makerere University, Kampala, Uganda.
Dan
D
Isabirye
Department of Biochemistry, Makerere University, Kampala, Uganda.
John
J
Okello
Department of Molecular Biology, Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan.
Ayman
A
Hussien
Welcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom.
Dominic
D
Kwiatksowski
Department of Genetics and Biology, School of Medicine and School of Arts and Sciences, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America.
Jibril
J
Hirbo
Department of Genetics and Biology, School of Medicine and School of Arts and Sciences, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America.
Sara
S
Tishkoff
Department of Molecular Biology, Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan.
Muntaser E
ME
Ibrahim
D000351:Africa, Eastern; D044383:Black People / Q000235:genetics*; D003576:Electron Transport Complex IV / Q000235:genetics*; D019143:Evolution, Molecular; D005260:Female; D040961:Genetic Drift; D063426:Human Migration; D006801:Humans; D008297:Male; D010802:Phylogeny
D003576:Electron Transport Complex IV