The results from the hair samples were consistent with the intestinal tissue results. Penn State graduate student Terry Melton and professor Mark Stoneking, who were involved in cross-checking the results, found that the mtDNA profile from the hair matched the profile from the tissue. Two different sample types, from materials with different chains of custody, producing the same result: that is the kind of internal corroboration that addresses reasonable concerns about any single source of biological material.
The convergence also addressed one specific category of skeptical argument: that the tissue sample might have been misidentified or contaminated, and was not actually from Anderson. If the tissue had been wrongly labeled or stored alongside other patients’ material, the hair from Manahan’s book — entirely independent in its provenance — would not be expected to produce the same profile. The match between the two sources provides reassurance that both samples were from the same individual.
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## Carl Maucher: The Living Link
The identification of Carl (or Karl) Maucher as the reference individual for the Schanzkowska comparison deserves its own section, because the logic of the mtDNA match is not self-explanatory.
Mitochondrial DNA is inherited exclusively through the maternal line: from mother to children, with high fidelity. A person’s mtDNA is essentially identical to their mother’s, and to their grandmother’s, and backward through the maternal line indefinitely (with rare mutations accumulating slowly over generations). If two people share the same maternal-line ancestor, their mtDNA will be identical or extremely similar.
Carl Maucher was identified as a descendant of Franziska Schanzkowska’s maternal line through Schanzkowska’s sister Gertrude. The exact relationship — described variously in sources as grandnephew or great-nephew through Gertrude — places Maucher and Franziska Schanzkowska as sharing the same maternal-line ancestor (their mother, and through her, the maternal line further back).