title: Signatures of the preagricultural peopling processes in sub-Saharan Africa as revealed by the phylogeography of early Y chromosome lineages.
abstract: The study of Y chromosome variation has helped reconstruct demographic events associated with the spread of languages, agriculture, and pastoralism in sub-Saharan Africa, but little attention has been given to the early history of the continent. In order to overcome this lack of knowledge, we carried out a phylogeographic analysis of haplogroups A and B in a broad data set of sub-Saharan populations. These two lineages are particularly suitable for this objective because they are the two most deeply rooted branches of the Y chromosome genealogy. Their distribution is almost exclusively restricted to sub-Saharan Africa where their frequency peaks at 65% in groups of foragers. The combined high-resolution single nucleotide polymorphism analysis with short tandem repeats variation of their subclades reveals strong geographic and population structure for both haplogroups. This has allowed us to identify specific lineages related to regional preagricultural dynamics in different areas of sub-Saharan Africa. In addition, we observed signatures of relatively recent contact, both among Pygmies and between them and Khoisan speaker groups from southern Africa, thus contributing to the understanding of the complex evolutionary relationships among African hunter-gatherers. Finally, by revising the phylogeography of the very early human Y chromosome lineages, we have obtained support for the role of southern Africa as a sink, rather than a source, of the first migrations of modern humans from eastern and central parts of the continent. These results open new perspectives on the early history of Homo sapiens in Africa, with particular attention to areas of the continent where human fossil remains and archaeological data are scant.
authors.affiliation: Institute of Evolutionary Biology, Universitat Pompeu Fabra-Institut de Biologia Evolutiva, Consejo Superior de Investigationes Cientificas, Barcelona, Spain.
authors.forename: Chiara
authors.initials: C
authors.lastname: Batini
authors.forename: Gianmarco
authors.initials: G
authors.lastname: Ferri
authors.forename: Giovanni
authors.initials: G
authors.lastname: Destro-Bisol
authors.forename: Francesca
authors.initials: F
authors.lastname: Brisighelli
authors.forename: Donata
authors.initials: D
authors.lastname: Luiselli
authors.forename: Paula
authors.initials: P
authors.lastname: Sánchez-Diz
authors.forename: Jorge
authors.initials: J
authors.lastname: Rocha
authors.forename: Tatum
authors.initials: T
authors.lastname: Simonson
authors.forename: Antonio
authors.initials: A
authors.lastname: Brehm
authors.forename: Valeria
authors.initials: V
authors.lastname: Montano
authors.forename: Nasr Eldin
authors.initials: NE
authors.lastname: Elwali
authors.forename: Gabriella
authors.initials: G
authors.lastname: Spedini
authors.forename: María Eugenia
authors.initials: ME
authors.lastname: D'Amato
authors.forename: Natalie
authors.initials: N
authors.lastname: Myres
authors.forename: Peter
authors.initials: P
authors.lastname: Ebbesen
authors.forename: David
authors.initials: D
authors.lastname: Comas
authors.forename: Cristian
authors.initials: C
authors.lastname: Capelli
mesh_terms: D017954:Africa South of the Sahara; D044383:Black People; D041322:Chromosomes, Human, Y / Q000235:genetics*; D004272:DNA, Mitochondrial / Q000235:genetics; D003710:Demography; D004641:Emigration and Immigration; D005828:Genetics, Population; D006239:Haplotypes / Q000235:genetics*; D006801:Humans; D018895:Microsatellite Repeats / Q000235:genetics; D058974:Phylogeography
chemical_list: D004272:DNA, Mitochondrial