I'm confused! How could mitochondrial DNA prove anything about Jefferson's descendants when he could not pass on any mtDNA! At least it is my understanding that that kind of DNA is passed only through the female line. While Jefferson would have gotten mtDNA from his mother, he could not have passed it to his children, male or female. So if he had a child with Sally Hemmings, the mtDNA that he/she got, and passed on (only if female), was Sally's alone, and would prove only that it was (or could have been) her descendant. Also, I'm pretty sure that the articles I read said that they tested Jefferson's male relatives. In a message dated 11/23/03 2:20:54 PM Eastern Standard Time, whitaker@innova.net writes: Thomas Jefferson's descendents are being traced through mitochondrial DNA as that is the only kind that can be used to trace ancestry by means of the female line. From what I've read -- and I've read everything I have been able to get my hands on about this -- the only definite finding is that Patsy Hemmings had children by Thomas Jefferson OR by one of two of his Randolph nephews. (Thomas Jefferson was related in multiple ways to the Randolphs as his mother was a Randolph and one of his sisters married a Randolph: during Jefferson's lifetime, and for a long time afterwards, it meant a lot more in Virginia to be related to the Randolphs than it did to be related to Thomas Jefferson.