The team developed a probabilistic approach — a method that works with limited genetic data by comparing the patterns of shared variation across the genome between the historical sample and living individuals, and estimating the probability that those patterns are consistent with a particular family relationship rather than with no relationship or a more distant one. The comparison group included DNA from other Lakota Sioux individuals, allowing the researchers to account for the shared ancestry that is expected among members of the same community.
The study was described, in reporting at the time of its publication, as the first use of ancient DNA to confirm a familial relationship between a historical figure and a living person. This claim of precedent is worth holding carefully: the methods developed for this case were novel in the specific sense that they extended kinship detection to a degraded sample at the level of a great-grandparent relationship, using a comparison framework that accounted for population-level genetic similarity.
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## What the Study Found and What It Didn’t Prove
The study’s conclusion, as stated in the published abstract and as described in the researchers’ public communications, is that the DNA analysis supported Ernie LaPointe’s claimed relationship to Sitting Bull at the level of a great-grandson.
This statement requires careful unpacking, because what the study did and did not establish matters for how it should be understood.
What the study established: The autosomal DNA extracted from the lock of hair, when compared with DNA from Ernie LaPointe and a reference group of Lakota Sioux individuals, produced results that were consistent with the relationship of great-grandparent to great-grandchild. The patterns of shared genetic variation between the historical sample and LaPointe were greater than would be expected by chance from two unrelated members of the same community, and the degree of sharing was consistent with what would be expected if Sitting Bull were LaPointe’s great-grandfather.