The DNA Legacy of Thomas Jefferson

Richard E. Green, Samuel H. Vohr, Joshua D Kapp, Jane E. Ailes, Samuel Sacco, Remy Nguyen, James Cahill, Peter D. Heintzman, Joanne Flores, Logan Kistler, Courtney A. Hofman, Robert C. Fleischer, Beth Shapiro, Richard Kurin

This article is a preprint and has not been certified by peer review [what does this mean?].

Allegations that Thomas Jefferson fathered the children of the enslaved Sally Hemings emerged in the context of U.S. presidential politics in the late 1700s and early 1800s and entailed strongly contested denials and affirmations by family members, biographers, and historians ever since. Previous analysis of Y chromosome markers in contemporary members of the Jefferson and Hemings patrilines was consistent with the paternity hypothesis but rejected by those who pointed out that, absent Jefferson DNA and its direct comparison to the DNA of possible descendants, other Jefferson males could have fathered Sally Hemings children. In this study, we developed an innovative technique to recover DNA from multiple rootless hair samples in a museum collection whose provenance, mitochondrial genomes, Y chromosome markers, and identity to each other indicate that these hairs and the DNA from them are from Thomas Jefferson. Using these DNA data, we find clear evidence of Thomas Jefferson ancestry in descendants of both his wife Martha Wayles Jefferson and Sally Hemings. We measured the amount of identical-by-descent DNA shared between Thomas Jefferson and his known and putative descendants. We find that the amount of shared Jefferson DNA is more likely under the model of direct Thomas Jefferson paternity than other proposed scenarios.

REG is co-founder and paid consultant of Astrea Forensics. SHV is employed by Embark Veterinary, Inc. BS is the chief science officer of Colossal Biosciences.

Copyright
The copyright holder for this preprint is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under a CC-BY-NC 4.0 International license. https://www.biorxiv.org/content/10.64898/2026.09.18.752809v1.full.pdf

A recent article in 'The Chronicle of Higher Education' points out that the oldest living descendent of Hemings who participated in this study has lost faith in it. She has fallen out with the author of this book and ended her association with the study and the Smithsonian. The article contains this quote from Dr. Brady-Atkins:

“I have spent five decades in academia and in science, and the conventions I was taught were not complicated ones. A finding is submitted to a journal. It is reviewed by those an editor selects rather than by those the investigator selects. It is published together with the data supporting it, so that others may test it. Only afterward is it written about for a general audience.” She pointed out that “this study has proceeded in the reverse order.”

She also states in the article that she just doesn't believe that Thomas was the ancestor of Hemings' children and believes there should be more investigation into Randolph, the brother of Thomas.

https://www.chronicle.com/article/the-smithsonian-used-her-dna-and-lost-her-trust

It's an extraordinary article. Mary Brady-Atkins is a sharp lady, and I predict that there will be a lot more fallout from this so-called 'study' and book.

I couldn’t be more ambivalent about this story.

If true, it merely shows that Jefferson was human. But I already knew that. If untrue, it shows that the haters are themselves all too human. And I already knew that.

Truth - and knowing what is historically true - matter.

We’ve had postmodern philosophers who have suggested that truth can be sacrificed to a political agenda, if the latter serves what THEY subjectively believe is the ‘greater good’.

But some of us believe that there is no greater good than Truth.

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