A new DNA study released on Thursday sheds new light on the horrors of the transatlantic slave trade, from the rape legacy seen in today's genetics to how diseases are likely to decimate some groups that are were forced to work in deadly conditions.
For example, DNA from an African region in the United States may be underrepresented because so many slaves died there from malaria on American plantations.
The grim results of a paper published in the American Journal of Human Genetics have gathered genetic data from 50,000 consenting research participants on both sides of the Atlantic.
These were compared to detailed records of slave ships that transported 12.5 million men, women and children between 1515 and 1865. About two million died on the trip.
"We wanted to compare our genetic results with those of the actual shipping manifest to see how they agreed and how they disagreed," Steven Micheletti, population geneticist at 23andMe, who recruited most of the participants, told AFP.
"And in some cases we see that they don't match up quite conspicuously," he added.
Unsettlingly, the research team found that practices that “watered down” the black legacy through measures that encouraged white men to have children with black women had a significant impact on the genetics of today's black Americans.
They also found that far more Nigerians than slaves were brought to the United States than previously thought, via slave trade ships from the Caribbean, a part of the black heritage that was previously little known.
A study conducted by 23andMe tracked the genetics of people on both sides of the Atlantic to uncover the countries from which black ancestors in America were violently brought overseas and enslaved
The researchers found that while the key African populations' genetic contributions broadly met the expectations they had based on historical records, there are important exceptions.
For example, most Americans of African descent have roots in Angola and the Democratic Republic of the Congo, in line with the major slave route.
But the Nigerian ancestry was overrepresented among African Americans in the U.S., probably due to the intra-continental slave trade that brought them from the Caribbean.
In contrast, there were fewer genetic connections between African Americans and the Senegambia region than expected when you consider how many were disembarked on slave ships in North America.
The probable reasons are bleak.
The study suggests that many more enslaved people in Nigeria were brought to the United States via the Caribbean than previously thought
"Because Senegambians in Africa were often rice growers, they were often transported to rice plantations in the United States," said Micheletti.
"These plantations were often malaria-stricken and had high mortality rates, which may have resulted in a reduced genetic representation of Senegambia among African Americans today."
In an interview with DailyMail.com, Dr. Micheletti added that he and his co-authors hope that their work will somehow honor the approximately two million people who died on ships to America to whom they were forcibly brought after their enslavement.
HISTORICAL POLICIES OF THE RACIC "WHITE" are reflected today in the genes of the Americans
A picture taken on October 18, 2017 shows registers, documents, and court records of slave merchant ships seized in the National Archives of the Government of Saint Helena in Jamestown in the British overseas territory of Saint Helena
Government and slave owner practices have also had a huge impact on African genetics.
Despite the fact that more than 60 percent of the enslaved people brought to America were men, comparisons of genetics show a strong tendency towards African female contributions in the modern gene pool of people with African heritage in the region.
Much of this is due to the rape of African women enslaved by white men and other forms of sexual exploitation, such as the promise of freedom when they have given birth to enough children.
However, the imbalance is even more pronounced in Latin America, where 70 percent of the slaves that survived the boat trips disembarked compared to the United States, the new study showed.
Guests participate in a flower-throwing ceremony to honor Africans who died at sea during the Atlantic slave trade during the 2019 landing ceremony on August 24, 2019 in Hampton, Virginia. Around two million people died on ships to America, where they were to be sold as slaves
In the United States, slave owners encouraged slave marriages to ensure that their children were the next generation of the forced labor pool.
The existence of these practices has been fairly well documented in historical documents, but genetics add a level of evidence to their existence and consequences.
"Genetics brings it to light and says that this was not just a story, but an event or practice that was big enough to change the genetics," said the study's co-author, Dr. Joanna Mountain, opposite DailyMail.com.
In countries such as Brazil and Cuba, governments implemented immigration policies in the 1900s, in which women of African descent married whites.
This brightening or "Branqueamento" policy was created with the aim of changing the lineage of blacks towards a supposed ideal of white.
& # 39; We have some regions where essentially 17 African women reproduce for every African man. We never expected the ratio to be that high, ”said Micheletti.
More men were enslaved than women, but the majority of those who reproduced were female.
In British colonized America, the ratio for every African man contributing to the gene pool is closer to 1.5 or two African women.
The researchers also found evidence of frequent intermingling between enslaved indigenous peoples and enslaved Africans in Latin America, which has been shown in previous work in the United States.
The researchers hoped not only to help people of African descent find their roots, but also to understand the historical experiences that shaped their genes today.