Taxonomic and phylogenetic signals in bovini cheek teeth: Towards new biosystematic markers to explore the history of wild and domestic cattle

Domestic cattle have contributed both to the rise of civilizations and the global loss of biodiversity, but the timing and mechanism of their domestication history remain to be fully understood. Palaeogenetics, which can now explore the target of human selection in the genome, have revolutionized our understanding of cattle domestication. However, biometric approaches of bone remains are still required as a prerequisite for targeted paleogenetic studies to document the taxonomic diversity of wild progenitors and the emergence of domestic morphotypes. But so far, biometric markers of cattle domestication have proven limited in their capacity to disentangle human intentionality from other biotic and abiotic factors.

Using a two-dimensional geometric morphometric approach (GMM), we assessed the taxonomic and phylogenetic signals of the enamel folding pattern of occlusal surfaces (EFPOS) in the maxillary and mandibular molars of wild and domestic species of the tribe Bovini, including ancient cattle breeds and archaeological aurochs and domestic cattle. The phylogenetic signal was assessed using a mitochondrial genome phylogeny across 11 wild taxa of the tribe Bovini. We found that EFPOS could accurately identify both the wild and domestic species of the Bovini taxa as well as shape differentiation among aurochs and modern and archaeological cattle. The phylogenetic differentiation among aurochs and both taurine and zebu cattle is strong, but the overall phylogenetic signal among the tribe Bovini is blurred by genetic introgression between wild and domestic Bos species in south-east Asia.

These results strongly suggest that the GMM analysis of dental traits are relevant markers that can be used before the implementation of targeted paleogenomic analyses as a mean to document the diversity and distribution of wild progenitors of domestic forms, identify the emergence of the earliest regional morphotype and their trajectory towards modern breeds.