Abolfazl Aali

Southwest and Central Asia were pivotal regions for the domestication and dispersal of domestic herbivores. Here we investigate long-term variation in bony labyrinth morphology of domestic bovids (sheep, goats and cattle) across the last 10 000 years. We focused on the osseous cavity of the inner ear, located within the petrous bone. We analysed semicircular canal (SC) size and shape using micro-computed tomography and geometric morphometrics (GMM) on 78 modern reference specimens and 234 archaeological petrous bones from 51 sites spanning the Iranian Plateau, Central Asia, the Caucasus and the Indus Valley. Bony labyrinth morphometrics yielded a strong taxonomic signal, enabling species-level identification of 228 out of 234 specimens and revealing greater diversity than anticipated. Comparative analyses further documented contrasting, nonlinear diachronic trajectories in SC size and shape among sheep, goats and cattle, reflecting species-specific responses to domestication and long-term herd management. Together, these results demonstrate that bony labyrinth GMM provides a robust, non-destructive framework for taxonomic identification and evolutionary inference and underscore how long-term, interdisciplinary approaches can capture the complex, nonlinear dynamics of animal domestication across the longue durée.

Mummified remains have long attracted interest as a potential source of ancient DNA. However, mummification is a rare process that requires an anhydrous environment to rapidly dehydrate and preserve tissue before complete decomposition occurs. We present the whole-genome sequences (3.94 X) of an approximately 1600-year-old naturally mummified sheep recovered from Chehrābād, a salt mine in northwestern Iran. Comparative analyses of published ancient sequences revealed the remarkable DNA integrity of this mummy. Hallmarks of postmortem damage, fragmentation and hydrolytic deamination are substantially reduced, likely owing to the high salinity of this taphonomic environment. Metagenomic analyses reflect the profound influence of high-salt content on decomposition; its microbial profile is predominated by halophilic archaea and bacteria, possibly contributing to the remarkable preservation of the sample. Applying population genomic analyses, we find clustering of this sheep with Southwest Asian modern breeds, suggesting ancestry continuity. Genotyping of a locus influencing the woolly phenotype showed the presence of an ancestral ‘hairy’ allele, consistent with hair fibre imaging. This, along with derived alleles associated with the fat-tail phenotype, provides genetic evidence that Sasanian-period Iranians maintained specialized sheep flocks for different uses, with the ‘hairy’, ‘fat-tailed’-genotyped sheep likely kept by the rural community of Chehrābād's miners.