lpetrich
Contributor
DNA: Transforming African American Genealogy | Legacy Tree
Only about 65% of American black men's Y chromosomes are (recent) African. Many of the rest are European, and many are likely from (male) slaveowners. By Y-chromosome comparison, Thomas Jefferson has been successfully identified as the father of at least one of his slave Sally Hemings's sons (Thomas Jefferson's Y chromosome belongs to a rare European lineage. - PubMed - NCBI, Jefferson–Hemings controversy).
Male slaveowners impregnating female slaves was something well-known, despite some slavery defenders' denials. At least one of those deniers, James Henry Hammond, a big defender of slavery, had done some of it himself. Not surprisingly, some abolitionists made a big issue about how, as one of them put it, the slave states were one big brothel.
Turning to mitochondria, most black Americans' mitochondria are African, and a few of them are Native American.
Autosomal chromosomes are those other than the sex-determining ones, the X and the Y. From autosomal DNA, American blacks have around 24% European ancestry and around 1% Native American ancestry.
So it is evident that most of the white contribution to American blacks' ancestry is male. Although slaveowners are an obvious and somewhat documented conrtibutor, a possible culprit in post-slavery years might be relationships between black women and white men being much more socially acceptable than between black men and white women. I don't know enough to say for sure, other than many black men having been lynched for being with white women. The first big film epic, "Birth of the Nation", depicted the Ku Klux Klan as protecting virtuous white women from lecherous black men.
The Genetic Ancestry of African Americans, Latinos, and European Americans across the United States: The American Journal of Human Genetics using data from 23andme.com. Has those and other results, like
Only about 65% of American black men's Y chromosomes are (recent) African. Many of the rest are European, and many are likely from (male) slaveowners. By Y-chromosome comparison, Thomas Jefferson has been successfully identified as the father of at least one of his slave Sally Hemings's sons (Thomas Jefferson's Y chromosome belongs to a rare European lineage. - PubMed - NCBI, Jefferson–Hemings controversy).
Male slaveowners impregnating female slaves was something well-known, despite some slavery defenders' denials. At least one of those deniers, James Henry Hammond, a big defender of slavery, had done some of it himself. Not surprisingly, some abolitionists made a big issue about how, as one of them put it, the slave states were one big brothel.
Turning to mitochondria, most black Americans' mitochondria are African, and a few of them are Native American.
Autosomal chromosomes are those other than the sex-determining ones, the X and the Y. From autosomal DNA, American blacks have around 24% European ancestry and around 1% Native American ancestry.
So it is evident that most of the white contribution to American blacks' ancestry is male. Although slaveowners are an obvious and somewhat documented conrtibutor, a possible culprit in post-slavery years might be relationships between black women and white men being much more socially acceptable than between black men and white women. I don't know enough to say for sure, other than many black men having been lynched for being with white women. The first big film epic, "Birth of the Nation", depicted the Ku Klux Klan as protecting virtuous white women from lecherous black men.
The Genetic Ancestry of African Americans, Latinos, and European Americans across the United States: The American Journal of Human Genetics using data from 23andme.com. Has those and other results, like
They also have 13% less European ancestry in their X chromosomes than over their genomes in general, indicating that their white ancestors also tended to be male. That paper didn't mention Y-chromosome results, however.We find that Latinos who, besides reporting as “Hispanic,” also self-report as Mexican or Central American, carry more Native American ancestry than Latinos overall; those also who self-report as black, Puerto Rican, or Dominican have higher levels of African ancestry; and those who additionally self-report as white, Cuban, or South American have on average higher levels of European ancestry.