South Africa's president, Jacob Zuma, has lashed out at British attitudes to "barbaric" Africans as he begins a state visit in London.

The remarks came after scathing British media coverage of the polygamous president and his chequered past, including the recent scandal of his 20th child, born out of wedlock. A Daily Mail article described him as a "sex-obsessed bigot" and "vile buffoon".

Zuma, due to meet the Queen and Gordon Brown today, countered with an attack on what he described as culturally superior views reminiscent of the British empire in South Africa.

NEW YORK - The government considers the African Burial Ground in Lower Manhattan the most important historic urban archaeological project in the United States. But most people don't know why.

Now, they can learn at a visitor center that opened Saturday at the site, where about 15,000 Africans were buried, many of them slaves. In the 1600s, they toiled for the Dutch colonizers of New Amsterdam, which became New York under the English.

NEW YORK-About 15,000 African slaves and their descendants were once unceremoniously buried under what is today Manhattan -- and forgotten.

On Saturday, a new visitor center opened near the rediscovered cemetery from the 17th and 18th centuries to celebrate the ethnic Africans who had toiled, many unpaid, to help make New York the nation's commercial capital.

"It's shocking -- the number of people today who are still unaware that this history exists in New York," said Tara Morrison, superintendent of the African Burial Ground National Memorial.

The individuals were selected by Vanessa M. Hayes of the University of New South Wales in Australia and Stephan C. Schuster and Webb Miller of Pennsylvania State University, and the genomes were decoded by Richard Gibbs and colleagues at the Baylor College of Medicine in Houston.

Dr. Hayes said Archbishop Tutu was selected because of his keen interest in medicine and because his parents come from the two largest Bantu groups in South Africa, the Sotho-Tswana and the Nguni.

CAPE COAST, Ghana (Reuters) - After outlining his bright hopes for Africa's future, President Barack Obama got a glimpse on Saturday into one of the darkest chapters of its past -- the transatlantic slave trade.

Obama, America's first black president, took his family for a poignant tour of Cape Coast Castle, a seaside fortress used by slave traders starting in the 17th century and which is now a monument to millions of Africans cast into slavery.

Africans are more genetically diverse than the inhabitants of the rest of the world combined, according to a sweeping study that carried researchers into remote regions to sample the bloodlines of more than 100 distinct populations.

The report, published yesterday in the journal Science Express, suggests that, because of historical migrations and genetic mixing across the continent, it will be hard for African Americans to trace their ancestry in fine detail. African American genealogies are increasingly popular and commercialized, but the authors of the new study cast doubt on how precise such searches can be, given the complexity of the genetic makeup of Africans.