STRIPES · The origin of living wild equids (zebras and asses): Fossils and molecules fill the gap in the evolutionary history of the genus Equus.

The evolutionary history of the genus Equus is a paradigmatic case of adaptation to different environments through time. Modern equids may be divided in two large groups based on genomic and morphologic evidence: the caballine horses (Przewalski’s and domesticated horses) and the stenonian wild equids (zebras and asses). Although molecular studies have clarified the evolutionary history of the caballine horses, the origin and evolution of the wild zebras and asses remains enigmatic, despite their well deciphered genomes. STRIPES aims to resolve the phylogeny of the genus Equus, with emphasis on extant zebras as well as African and Asian asses. To do so, I plan to study the fossil horses collections housed at the ICP (Sabadell, Spain), of the the MNHN (Paris, France) and of the NHMUK (London, England). These institutions have important collections from key sites in Eurasia and Africa, with ages matching with the estimated divergence time interval between zebras and asses at ca. 1.8 Ma. I will use 2D and 3D geometric morphometric approaches to more accurately characterize the anatomy of the fossil and living Equus species, and I will further integrate morphological information with genomic (paleoproteomic and molecular) data to perform the first Bayesian total evidence (tip dating) phylogenetic analysis of the genus Equus, which will enable to refine the branching topology and estimated divergence dates of its main lineages. The combination of paleontological and neontologial data, both morphological and molecular, represents a transverse approach of this study between Paleontology, Zoology, and Molecular Biology. The results of this project will yield the most complete phylogeny of the genus Equus thus far, pushing forward the current state-of-the-art and clarifying the evolution and origin of the living zebras and asses. Moreover, this project will also provide important information for the Conservation (Paleo)biology of these threatened and endangered wild animals.