Genetic sleuths have discovered the earliest known trace of Africa’s contribution to the native British gene pool — from a man who lived in northern England in the late 1700s.
Launching an analysis of British genetic diversity, scientists recruited 421 men who described themselves as British and analysed their Y chromosome, which is handed down by the paternal line.
One of the men was found to have an unusual type of chromosome, hgA1, which is normally found in West African males.
As the man had an unusual surname, derived from a village in the east of northern English county of Yorkshire, the team endeavoured to track down other men with the same monicker.
Of 18 such men who were traced and volunteered a sample of DNA for testing, seven were found to carry the same HgA1 chromosome haplotype.
The next step was documentary research. The team carried out a genealogical probe, discovering that the eight were united by a common ancestor, a man who lived in Yorkshire around 1780.
Who that individual was remains a mystery. He could have been a first-generation immigrant from Africa, or perhaps he himself was a descendant of such a man.
”Our findings represent the first genetic evidence of Africans among ‘indigenous’ British and emphasise the complexity of human migratory history,” says the study, lead-authored by geneticist Mark Jobling at the University of Leicester, central England.
The paper appears in the European Journal of Human Genetics.
The authors say that this discovery highlights the pitfalls of assigning a geographical origin to types of Y chromosomes.
Human migration has been continuing for so long and across such huge distances that an individual’s chromosomal heritage may no longer be pinned reliably to a region or a continent, they say.
Around 8% of the United Kingdom’s population of 54-million belong to ethnic minorities and, in the 2001 census, more than one million classified themselves as ”Black or Black British,” the paper says.
For many Britons, immigration began soon after World War II, but in fact contact with Africa — and thus the opportunity for genetic mingling — occurred many centuries before.
Africans were first recorded in Britain 1 800 years ago, as ”a division of Moors” in the Roman army deployed along Hadrian’s Wall to ward off the Scots.
The Atlantic slave trade also brought West Africans to Britain from about the 16th century, many of whom worked as servants, musicians and entertainers.
By the last third of the 18th century, there were an estimated 10 000 Africans in Britain, mostly concentrated in cities such as London, the paper says.
The ”Out of Africa” hypothesis takes Africa’s legacy much farther back.
It says that all six billion humans alive today are descendants of small groups of Homo sapiens who ventured out of East Africa around 200 000 years ago and then spread around the world. – AFP
