Still, the father passed a Y chromosome to Hemings’ children which corresponds to a haplogroup in the Jefferson line.
That is not proof that Thomas was the father, it is only proof that A Jefferson Male may have been. There were numerous Jefferson men who could have passed that on, and one of them was often at Monticello and socializing with the slaves.
Understood. But this article contends that Sally Hemming’s descendents have Jefferson’s mitochondrial DNA which according to the current understanding of mammalian biology is impossible, making this study irrelevant.