DNA reveals dark history of slavery
NEW YORK: A new DNA study published Thursday sheds fresh light on the horrors of the transatlantic slave trade, from the legacy of rape that can be seen in today’s genetics to how disease likely decimated some groups forced to work in deadly conditions.
For example, DNA from one African region may be under-represented in the US because so many slaves from there died of malaria on American plantations.
The grim results from a paper, which appeared in the American Journal of Human Genetics, compiled genetic data from 50,000 consenting research participants from both sides of the Atlantic.
It cross-referenced these with detailed records from slave ships that transported 12.5 million men, women and children between 1515 and 1865. Some two million died on the journey.
“We wanted to compare our genetic results to those actual shipping manifest to see how they agreed and how they disagreed,” Steven Micheletti, a population geneticist at 23andMe, which recruited most of the participants, said.
“And in some cases, we see that they disagree, quite strikingly,” he added.
The researchers found that while the genetic contributions from major African populations largely correspond to what they expected based on historic records, there are major exceptions.
For instance, most Americans of African descent have roots in Angola and the Democratic Republic of the Congo, in line with the major slave route.
But Nigerian ancestry was overrepresented in African Americans in the US, probably because of the intracontinental slave trade which brought them from the Caribbean.
By contrast, there were fewer genetic connections between African Americans and the Senegambia region than would be expected given the number who disembarked on slave ships in North America.
“Because Senegambians were commonly rice cultivators in Africa, they were often transported to rice plantations in the US,” Mr Micheletti said. “These plantations were often rampant with malaria and had high mortality rates, which may have led to the reduced genetic representation of Senegambia today.”