Re-evaluating Amarna: A Full-Pedigree Likelihood Assessment of 18th-Dynasty STR Evidence

The family relationships of the late 18th Dynasty have been debated because theavailable ancient-DNA evidence is sparse, partially observed, and embedded in competinghistorical reconstructions. This paper re-evaluates the published Amarna STR evidencewith an exact full-pedigree likelihood framework. The analysis uses the eight nuclear STRloci reported for the royal mummies by Hawass et al. (2010), locus-specific allele-frequencypriors derived from the Huckenbeck/Duesseldorf STR database, Mendelian transmission,andanexplicitobservationmodelforcomplete, partial, andmissingprofiles. Eachcandidatereconstruction is evaluated as P(D |M), where D denotes the observed STR data andM specifies the pedigree, identity assignments, founder priors, and error assumptions.Across four Run-I scenario families, the Hawass-derived and Bommas architectures receiveidentical top likelihoods and jointly dominate the tested alternatives; the nearest non-tied alternative is lower by 7.71–10.30 log-likelihood units. The STR evidence thereforestrongly supports a shared genetic structure but does not by itself decide every historicalname assigned to that structure. KV55 is treated accordingly: within the tied geneticarchitecture, the Smenkhkare identification is historically preferable under the osteologicaland contextual interpretation adopted here; it is not a result generated by the STRlikelihood itself. KV21B remains scenario-dependent, with daughter placements favoredin two N-scenarios, a Nefertiti placement favored in one, and only moderate support fora daughter placement in the fourth. Robustness checks show that some subclaims arestable across tested assumptions, whereas others depend on founder priors or individualloci. The main conclusion is that the available STRs are strongest as evidence for pedigreestructure, while several historical identity labels remain conditional on non-genetic evidenceor explicitly stated historical priors.