My mother’s great-grandmother, Louisa “Lue” Bobo Danner, was born on January 21, 1842, on the plantation of Dr. William J. Bobo in Union County, South Carolina. She was the eldest of the many children born to Clarissa Bobo, an enslaved woman on the Bobo plantation. Around 1859, Dr. Bobo relocated to Panola County, Mississippi, bringing my ancestors with him.

For generations, my family’s oral history accurately maintained that Lue’s biological father was a white man with the surname Wilbourn, although his given name had long been forgotten. Over the years, traditional genealogical research combined with DNA evidence gradually narrowed the possibilities. The most likely paternal candidate emerged as one of the four adult sons of William Wilbourn (1765–1822) and his wife, Susannah Gibbs (1781–1814), of Union County, South Carolina. Among those brothers, Joshua Wilbourn emerged as my strongest candidate.

However, one significant obstacle remained. Joshua had a twin brother, Elijah Wilbourn, and no historical record has been found indicating whether the twins were identical or fraternal. That distinction could have a major impact on the interpretation of autosomal DNA evidence, making this a complex genetic genealogy case.

With the emergence of artificial intelligence tools, I decided to present this challenging case to ChatGPT Plus. To give the analysis the strongest possible foundation, I supplied an extensive DNA dataset that included the shared DNA amounts between six of Lue Danner’s great-grandchildren and twenty-seven descendants of William and Susannah Wilbourn through their sons Elijah, Joshua, Alfred, and Hiram. See below. I also asked ChatGPT to evaluate whether the available DNA evidence could help distinguish between Elijah and Joshua as Lue’s possible father and whether it might provide any clues as to whether the twins were identical or fraternal.

The following is ChatGPT’s analysis of this complex paternity question, along with its assessment of the twin scenario and the strengths and limitations of the available genetic evidence.

My prompt:

Please provide some hypotheses and probabilities on how Lue Danner was related to Elijah Wilbourn, his twin brother Joshua Wilbourn, and their full brothers, Alfred and Hiram Wilbourn, based on DNA. These twin brothers, who were white, were born in 1805, their brother Alfred was born in 1803, and their brother Hiram was born in 1807, all in South Carolina. It is not known if Elijah and Joshua were identical or fraternal twins. The attached spreadsheet contains 6 descendants of Elijah Wilbourn, 11 descendants of Joshua Wilbourn, 5 descendants of Alfred Wilbourn, 5 descendants of Hiram Wilbourn, and their DNA sharing with six great-grandchildren of Lue Danner. Lue Danner was born enslaved in South Carolina in 1842. According to oral history, she was fathered by a white Wilbourn. Descendants 1, 2, and 3 of Lue Danner in columns C, D, and E are full siblings. Descendant 4 of Lue Danner in column F is a first cousin to descendants 1, 2, and 3, but all four of them are grandchildren of Lue Danner’s daughter, Mary. Descendants 5 and 6 of Lue Danner are first cousins to each other, as their grandmother was Lue’s daughter, Laura. Descendants 5 and 6 are second cousins to Descendants 1, 2, 3, and 4. Therefore, Descendants 1 – 6 are all great-grandchildren of Lue Danner. Based on the DNA, what are some hypotheses and probabilities of how Lue Danner was related to the four Wilbourn brothers. Based on DNA, is it possible to ascertain if Elijah and Joshua were identical or fraternal twins?

ChatGPT Plus wrote:

Core DNA pattern

The DNA evidence strongly supports that Lue Danner had close biological ancestry from the Wilbourn family, consistent with the oral history that she was fathered by a white Wilbourn.

DNA summary by Wilbourn brother

Wilbourn brother	Descendants tested	Nonzero matches	Total shared cM	Average cM per comparison
Joshua Wilbourn	11	58 of 66	2,607 cM	39.5 cM
Elijah Wilbourn	6	31 of 36	901 cM	25.0 cM
Alfred Wilbourn	5	22 of 30	564 cM	18.8 cM
Hiram Wilbourn	5	20 of 30	441 cM	14.7 cM

Main interpretation

The DNA strongly supports that Lue Danner was closely connected to the Wilbourn family, consistent with the oral history that she was fathered by a white Wilbourn.

The strongest DNA signal is with Joshua Wilbourn’s descendants, followed by Elijah, then Alfred, then Hiram.

Most likely hypotheses

Hypothesis	Estimated probability
Joshua Wilbourn was Lue Danner’s father	35–45%
Elijah Wilbourn was Lue Danner’s father	20–30%
Alfred Wilbourn was Lue Danner’s father	10–15%
Hiram Wilbourn was Lue Danner’s father	5–10%
Another close male Wilbourn relative was Lue’s father	10–15%
The Wilbourn connection came through Lue’s mother or a more distant ancestor	5–10%

Why Joshua is the strongest candidate

Joshua’s descendants have the highest overall DNA sharing, the highest average, and the largest individual matches, including values over 100 cM with some of Lue’s great-grandchildren. His line also shows broad matching across both Lue’s Mary and Laura descendant lines.

Why Elijah remains very plausible

Elijah’s line has a strong match pattern too, including several matches above 50 cM and one as high as 87 cM. He cannot be ruled out, especially because he was Joshua’s twin and full brother.

Why Alfred and Hiram are less likely

Alfred and Hiram descendants also match Lue’s descendants, which is expected if Lue’s father was one of the Wilbourn brothers. But their totals and averages are lower, making them possible but less favored.

Can DNA determine whether Elijah and Joshua were identical or fraternal twins?

Not from this spreadsheet alone.

If Elijah and Joshua were identical twins, their descendants could look genetically as if they descend from the same man, making it nearly impossible to distinguish which twin fathered Lue using autosomal DNA alone.

If they were fraternal twins, they would be genetically like ordinary full brothers. In that case, chromosome segment data and direct comparisons between Elijah and Joshua descendants might help.

Bottom line

The DNA supports a high probability that Lue Danner’s father was one of the Wilbourn brothers or a very close male Wilbourn relative.

My strongest ranking is:

Joshua first, Elijah second, Alfred third, Hiram fourth.

Overall, I would estimate an 80–90% probability that Lue’s father was in this immediate Wilbourn brother group or very close to it.