Every gene tells a story

Izelle Theunissen, MRC News

Genes reveal more than whether you were going to have a crooked nose or curly hair. They can also spill the beans about where your ancestors come from. Dr Himla Soodyall of the MRC's Human Genomic Diversity and Disease Research Unit tells more about the origins of the Lemba.

The Lemba (or Remba, as they are known in Zimbabwe) is a group of Bantu-speakers who tell a fascinating account of their ancestry. Now genetic techniques pioneered by Dr Soodyall and her team bear their legends out.

History and traditions

According to the Lemba's oral history that is passed from generation to generation, they have Jewish ancestors. Prof. Mativha, head of the Lemba Cultural Association and author of the book titled The Basena/Vamyena/Balemba has strongly supported this oral tradition. "Their forefathers were traders who migrated from the 'north' to the Yemen around 7 BC, where they established a large community at Sena and several trading posts along the eastern African coast. The Jewish community at Sena, called 'Basena', was later expanded by exiles escaping from the Babylonian destruction of Jerusalem in 586 BC," Prof. Mativha claims.

Later on, when conflict between the 'Basena' and the Arabs surfaced, some 'Basena' migrated to Africa. Here they split into two groups - one moving westward to settle in Ethiopia (the Ethiopian Jews) and the Lemba moving southward, finally establishing communities in Southern Africa. Some of the traditions practiced by the Lemba today are similar to those practiced by Jews: they also practise circumcision, bury their dead, offer animal sacrifices, hold the first and seventh days of the moon to be sacred, keep kosher, cut the throat of animals during slaughter, keep ritual purity and don't marry the 'gentiles'.

Several historical facts also set them apart from their Bantu-speaking neighbours: they are highly skilled metal workers (including iron, copper and gold) and potters and the men wear long cotton garments.

"The Lemba didn't retain their own language - the Lemba of the former northern Transvaal speak Venda and in Zimbabwe they speak one or other western dialects of Shona. But even today, there are still Lemba in Venda who can recall much about the language spoken by their ancestors from before the end of the 17th century when they migrated to the south of the Limpopo," Dr Soodyall says.

Research starts

This fascinating story has sparked the interest of many other scientists: Tudor Parfitt, author of Journey to the vanished city: The search for a lost tribe of Israel, spent months travelling through Africa and Yemen searching for the geographic origins of the Lemba. He wrote: "Most of the evidence then suggests that the past of the Lemba was connected with the Arab world. Ethiopian or Indian antecedents seemed to be based on far more flimsy evidence. But that being the case, the question still remains: where was the original Sena? Somewhere no doubt in the Arabic-speaking world. But where?"

Dr Margaret Nabarro, the well-known ethno-musicologist with a deep knowledge of Lemba traditions, also became convinced of the Semitic connection of the Lemba. "She and her husband, Prof. Emeritus Frank Nabarro, encouraged Prof. Trefor Jenkins from the National Health Laboratory Services (previously SAIMR) to pursue genetic studies on the Lemba. So, during two visits to the annual cultural festivals of the Lemba in Venda, Prof. Jenkins collected blood samples from about 100 volunteers to use for genetic studies," says Dr Soodyall.

What the Y chromosomes tell

In contrast to mitochondrial DNA (mtDNA) which is passed on exclusively from mother to child and is useful in tracing the ancestry of human populations along female lineages, Y chromosomes are found only in males.

"Using mtDNA the Lemba were indistinguishable from other Bantu-speaking groups. However, when my colleague Mandy Spurdle analysed the Y chromosomes in the Lemba, she found that approximately 50% of the Y chromosomes present in the Lemba appeared to be from Semitic (Jewish or Arab) origin. Thirty six per cent was of African origin, and the ancestry of the remaining 14% could not be resolved by the methodology used at the time. This study sparked a great deal of interest among researchers interested in the origins of the 'Black Jews' of South Africa," says Dr Soodyall.

           

Origins of Y chromosomes in Lemba and Remba.

"A group of researchers at the University College in London recently extended a genetic approach first adopted by our laboratory to resolve the Y chromosome lineages found in the Lemba. These researchers found that a particular Y chromosome combination or haplotype - known as the Cohen Modal Haplotype or CMH - was present in the Lemba at a frequency of about 9%. This haplotype is only found at high frequency in Jewish priests, so this seems to corroborate the Lemba oral history about their origins," explains Dr Soodyall.

In her own research Dr Soodyall and her team have found that about 50% of the Y chromosomes found in the Lemba and Remba have a Middle Eastern origin. "But the CMH was only found in the South African Lemba. We are presently analysing the data to establish whether the CMH was introduced recently, perhaps from a Jewish ancestor into the Lemba, or whether it was introduced from one of the founders of the Lemba who originated in 'Sena', the presumed homeland of the Lemba," she says.

 

February 2003