Lesotho was the last part of southern Africa to be settled by Bantu-speaking peoples, when they reached its western lowlands in about AD 1600, and the highland regions from about the 1870s. Prior to this Lesotho was inhabited by San groups (the so called Baroa or “Mountain Bushmen”). Genetic studies have suggested that southern African Khoisan possess some of the oldest, most distinctive lineages still extant. Archaeological evidence also supports these findings, with southern Africa being home to some of the oldest known anatomically modern human fossils.
Unfortunately, the majority of genetic studies in sub-Saharan Africa so far have concentrated on a very small number of samples from a limited number of populations, meaning that the genetic variation of the populations living in this region have been only sparsely surveyed. While oral histories and archaeological studies have explored admixture between the immigrant Bantu farmers and the San, limited genetic data is available on this.
Therefore, studying the people of Lesotho could help shed some light onto the genetic diversity of southern Africa, as although the San are no longer occupants of Lesotho, through admixture with the Bantu famers their descendants are. DNA sampled from living peoples in Lesotho can be used to provide proxy evidence of the genetic variation that originally characterised the southern San. In addition, study of the Lesotho population will provide evidence as to the admixture that might have occurred between the hunter-gatherers and immigrant farmers.
During October-November 2009 samples were collected in Lesotho from communities in both highland and lowland regions. The project has been carried out in collaboration with archaeologists, and samples were collected in areas where archaeological excavations have been conducted.
MtDNA and Y chromosome analysis is currently ongoing and will be analysed by comparison with data already available for other Khoisan populations. As part of this project we also plan to investigate low recombination autosomal regions and compared with samples from other regions. Information collected with regards to participants ethnic groups and languages spoken will also be analysed in order to aid conclusions about admixture events.
We would like to thank the significant support and help of The Lesotho Ministry of Health and Social Welfare, The Lesotho Ministry of Local Government, The Lesotho Ministry of Tourism, Environment and Culture. This work would not have been possible without the people of Lesotho: we would like to thank of all the volunteers for their cooperation and agreement to give samples as well as all the people that in different ways made this project possible. We would like to thanks among the others Njapeli Matlanyane and Nthontsi Qokolo for their invaluable help during the sampling sessions. Chiara Batini, Sarah Marks and George Busby are greatly acknowledged for their invaluable support in the organization of the expedition and the collection of the samples. Peter Mitchell & Charles Arthur (University of Oxford) and Brian Stewart (University of Cambridge) provided instrumental advice on sampling and logistics. We finally would like to thank the Boise Fund for providing funding to conduct this research.
Papers published on Lesotho data: Marks et al, 2012, Marks et al, 2014, González-Santos et al, 2015, and Montinaro et al, 2016.
Pictures by: Chiara Batini