The 2026 DNA Study and
Tennessee Petition

Overview

A court petition has been filed in Nashville, Tennessee, seeking authorization under state law to obtain DNA samples from the grave of John Randolph Jefferson (1816–1845). John Randolph Jefferson, who died childless with no next of kin, was the last son of Randolph Jefferson (1755–1815), the younger brother of Thomas Jefferson.

The petition addresses a limitation revealed by the 1998 Jefferson–Hemings DNA study, published in Nature: the absence of genetic data from Randolph Jefferson and his male-line descendants. That limitation became apparent only after publication of the study and the scientific criticism that followed.

The petition is a matter of public record and is posted by the Tennessee Historical Commission as part of its cemetery petitions archive.

"The instant Petition is the first step in a process that will provide much needed insight into the alternate theories of paternity for Sally Hemings children or, as it may turn out, further confirmation of Thomas Jefferson’s paternity. Either way, the search for the truth will be advanced by granting this Petition."

Petition updates as of 19 February 2026: Motion to Dismiss, Response to Motion to Dismiss, Exhibit A: Father Ryan Petition, Exhibit B: Father Ryan Final Order, Exhibit C: Proof of Publication; Reply in Support of Respondent’s Motion to Dismiss.

How Randolph Jefferson Emerged as a Paternity Candidate

Prior to 1998, Randolph Jefferson was not regarded by historians or scientists as a serious paternity candidate in the Jefferson–Hemings paternity question. Aside from a brief and quickly dismissed reference in a 1958 letter from a historian to a Jefferson scholar, Randolph Jefferson did not figure prominently in the historical literature.

This changed after publication of the 1998 DNA study, which established that a male from the Jefferson paternal line fathered Eston Hemings, while simultaneously demonstrating that Y-chromosome testing could not identify which Jefferson male was responsible.

In January 1999, scientists writing in Nature (including David M. Abbey and Gary Davis) emphasized that the study’s conclusions were incomplete because Y-DNA cannot distinguish among brothers, uncles, nephews, or cousins; Randolph Jefferson and his sons would produce identical Y-DNA results; and alternative Jefferson males such as Randolph and his sons had not been examined.

Following these critiques, historians and genealogists began re-examining Randolph Jefferson’s life, movements, social behavior, proximity to Monticello, and contemporaneous testimony. That post-1998 reassessment uncovered evidence that had not been systematically evaluated before and raised substantial questions about the assumption that Thomas Jefferson was the only plausible Jefferson male candidate.

Scientific Rationale

While the 1998 study was groundbreaking, its reliance on Y-STR (Short Tandem Repeat) testing from descendants of Field Jefferson only established that a male Jefferson was the father of Eston Hemings. Because Thomas and Randolph Jefferson were brothers, they shared an identical Y-STR signature, leaving the question of specific paternity statistically unresolved at that time due to the scientific limitations of 1990s DNA testing.

The current DNA study seeks to provide the specificity that 1990s technology lacked in two primary ways.

1. Moving Beyond Y-STR to Y-SNP Analysis

The 1998 test examined a small number of Y-STR markers that mutate very slowly over time. Modern “Big Y” testing examines tens of thousands of Y-SNPs (Single Nucleotide Polymorphisms).

While brothers typically share the same Y-DNA profile, it is technically possible for a de novo mutation to have occurred in Randolph Jefferson’s line that was not present in Thomas Jefferson’s. Since Randolph Jefferson’s grave has never been found, by testing John Randolph Jefferson, the study establishes a definitive “Randolph baseline”, making it possible to evaluate whether the DNA of Eston Hemings’s descendants aligns more closely with a specific branch of the Jefferson family tree rather than only the general Jefferson haplotype.

2. The Power of Autosomal DNA and Next-Generation Sequencing (NGS)

Perhaps most importantly, autosomal DNA testing was not available for genealogical or forensic use in 1998. Autosomal DNA examines the 22 pairs of non-sex chromosomes inherited from all ancestors, rather than focusing solely on the paternal Y-line.

In the 1990s, researchers could examine only a single, narrow genetic window — the Y-chromosome. Today, using Next-Generation Sequencing (NGS), it is possible to perform SNP capture on degraded historical remains and analyze autosomal DNA at a genome-wide level.

This allows researchers to compare the total genetic distance between descendants of Eston Hemings and descendants of Randolph Jefferson, using Identical-by-Descent (IBD) segment analysis to identify shared inheritance from recent common ancestors.

The Technical Distinction

Statistically, Eston Hemings’s descendants would be expected to share a different amount and pattern of autosomal DNA with a great-uncle’s line (Thomas Jefferson) than with a direct grandfather’s line (Randolph Jefferson). This whole-genome approach provides a level of forensic resolution that the 1998 study could not contemplate, even in principle.

Why First-Generation Jefferson DNA Matters

Modern forensic genetics increasingly emphasizes autosomal DNA and IBD analysis because first-generation descendants preserve larger, less-degraded DNA segments and enable clearer differentiation among closely related family lines.

Independent research efforts are currently exploring whether usable DNA can be recovered from historical Jefferson artifacts, including hair samples associated with Thomas Jefferson and his adult daughters Martha and Maria Jefferson. While this work remains ongoing and unpublished, it underscores a broader scientific principle: DNA from first-generation Jefferson descendants offers the most promising opportunity to clarify unresolved questions raised by earlier studies.

The Tennessee petition is consistent with this principle by focusing on a first-generation descendant of Randolph Jefferson whose genetic profile was never previously examined.

Why We Do Not Rely on Distant-Descendant Autosomal Matching Alone

Autosomal DNA analysis can be a powerful tool, but when applied to questions of paternity involving ancestors five, six, or seven generations in the past, it carries a well-documented risk of false positives—apparent genetic matches that are not inherited from the same ancestor (often described as identical by state rather than identical by descent).

At deep generational distances, truly inherited DNA segments become shorter and rarer, while chance matches become more common. As a result, comparisons among distant descendants alone can produce misleading signals if not carefully controlled, particularly when conclusions are drawn from small shared segments or limited sample sets.

Autosomal DNA is different from Y-DNA (which is limited to patrilineal males), as it can use all people (females, cousins, etc.) for paternity research. The fact that two people who match on a segment of DNA each received it from a common ancestor has significant value to assessing lineage. Autosomal DNA is passed from any parent to child through the generations, so we have 50% of each parent's DNA, 25% of each grandparent's DNA, etc. However, each generation dilutes by 50% the DNA connection to ancestors - the closer the generations, the more accurate the results.

For this reason, the 2026 DNA study does not rely solely on autosomal comparisons among fifth-, sixth-, or seventh-generation descendants to infer 18th-century paternity. Instead, the study design prioritizes first-generation Jefferson-line DNA, combined with modern sequencing methods and conservative analytical thresholds, to reduce ambiguity and minimize the risk of false-positive inference.

This approach reflects current best practices in genetic genealogy and forensic genetics and is intended to address limitations that were unavoidable in earlier studies.

Scientific Appendix: Methods and Terminology

Y-STR (Short Tandem Repeat) Testing

Y-STR testing examines repeating DNA sequences on the Y-chromosome. These markers mutate slowly and are useful for identifying broad paternal lineages. However, because brothers typically share identical Y-STR profiles, this method cannot distinguish between closely related male relatives.

Y-SNP (Single Nucleotide Polymorphism) Testing

Y-SNP testing examines tens of thousands of single-base changes across the Y-chromosome. While most Y-SNPs are shared among close relatives, rare de novo mutations can create branch-specific markers. Modern “Big Y” testing significantly increases the resolution available for distinguishing paternal sub-lineages.

Autosomal DNA

Autosomal DNA consists of the 22 pairs of non-sex chromosomes inherited from all ancestors. Unlike Y-DNA, autosomal DNA reflects contributions from both maternal and paternal lines and allows for whole-genome comparison.

Next-Generation Sequencing (NGS)

NGS enables high-throughput DNA sequencing and makes it possible to recover usable genetic data from highly degraded historical remains through techniques such as SNP capture.

Identical-by-Descent (IBD) Analysis

IBD analysis identifies DNA segments shared by individuals because they were inherited from a recent common ancestor. The amount, length, and distribution of shared IBD segments vary depending on the degree of relatedness and can help differentiate between competing genealogical hypotheses.

Statistical Implications

From a population-genetics perspective, Eston Hemings’s descendants would be expected to share:

fewer and smaller autosomal segments with a great-uncle’s line, and
more extensive shared segments with a direct grandfather’s line.

These differences form the basis of comparative autosomal analysis in the current study.

Legal Status

The petition is pending and subject to judicial review under Tennessee law.

No authorization has been granted to extract DNA samples from John Randolph Jefferson at the time of writing.

Nothing on this site constitutes legal advice or asserts the outcome of any court proceeding.

Why JeffersonDNA.org Covers This Petition

JeffersonDNA.org exists to examine evidence rigorously and transparently. The 2026 DNA study represents an effort to address unanswered scientific questions identified after the 1998 DNA study by introducing genetic data from a Jefferson lineage that had not previously been examined, using modern forensic methods unavailable at the time of the original study.

The 2026 DNA Study and Tennessee Petition