Back to your roots - with DNA
of Leicester geneticists have been involved in a pioneering study attempting
to trace the origins of British African-Caribbean people, whose ancestors were
uprooted from Africa in the slave trade hundreds of years ago, and transported
across the Atlantic to work on sugar plantations.
In the study,
conducted for the BBC documentary film Motherland (February 14, 9pm BBC2), Dr
Mark Jobling of the University of Leicester found that more than a quarter of
British African-Caribbean men have a Y chromosome (passed from father to son)
which traces back to Europe rather than Africa. In contrast it was
found that only around 2% of British African-Caribbeans have mitochondrial DNA
(passed from mother to child) which traces to Europe.
Mark Jobling said of his findings:
"This really reflects the sexual politics of the situation of slavery.
This was a power relationship between these two populations and in that power
relationship it was European men who were having sex with African women."
A third test,
looking beyond specific paternal and maternal inheritance to genes passed from
both parents, was carried out by Mark Shriver from Pennsylvania State
University in the USA. This showed an average European ancestry of about 13% -
so people living in Britain who have very different skin colours really share
a lot of common ancestry.
As well as
looking at the origins of the population as a whole, the 228 participants were
given individual information about their ancestors. The most striking success
of the study was to 'reunite' an African-Caribbean woman from Bristol with
living African relatives on a tiny island off the coast of Cameroon. Dr Peter
Forster from the McDonald Institute in Cambridge who specialises in
mitochondrial DNA analysis used a global database to match the DNA belonging
to 37 year old Beaula McCalla. Only eight people in the global database
exactly matched with Beaula, and they all came from the Bubi population on the
tiny island on Bioko. After further testing of the intrigued islanders, Beaula
was flown out to Bioko for a truly historic reunion with her relatives.
The value of
this kind of study for African-Caribbeans in particular is that the different
cultures, languages and ethnicities of their ancestors were lost in the slave
trade, in a system that treated them as commodities rather than people. DNA
evidence offers some hope of reconnecting these people to their roots. The
study also raises some concerning issues, however; Mark Jobling points out
that "in using mitochondrial DNA or Y chromosomes to trace someone’s
roots we are focusing on only one ancestor out of very many, which can be
misleading. Also if, as seems likely, commercial companies soon offer these
ancestry services, we need to be sure that they provide reasonable
interpretations of results, and maybe even counselling for people who find
some of the implications difficult to deal with".
Last updated: 7 February 2003 10:55
Created by: Rachel Tunstall
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