The evolution and phenotypic convergence in Malagasy tenrecs (Afrosoricida, Tenrecidae): a combined molecular and morphological perspective

• Applicants: Dr. Patrick Arnold; Professor Dr. Michael Hofreiter
• Subject Area: Evolution, Anthropology ; Ecology and Biodiversity of Animals and Ecosystems, Organismic Interactions ; Systematics and Morphology (Zoology)
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 515851100

Madagascar is renowned for the strikingly high endemicity of its native mammalian fauna. Among this, Malagasy tenrecs (Tenrecidae) are outstanding for their radiation into shrew-like, mole-like, hedgehog-like and semiaquatic ecomorphs. Yet, our understanding of their evolution and diversification after the colonization of Madagascar is still limited. Tenrecs have long been united with other small-sized, insect-feeding and in many aspects plesiomorphic mammals, such as shrews, moles and hedgehogs, into the taxon Insectivora. With the emergence of phylogenomic data, however, it could be shown that Insectivora contains two, not even closely related lineages of placental mammals: the Eulipotyphla (shrews, moles, hedgehogs) that originated on northern continents (Laurasia), and the Afrosoricida (tenrecs, golden moles, otter shrews) with Afro-Malagasy distribution. This further implies that Malagasy tenrec ecomorphs represent a conspicuous case of convergent evolution with regards to shrews, moles and hedgehogs of northern continents. Due to phylogenetic issues and the lack of molecular resources, the genomic basis behind this phenotypic convergence and how rates of morphological evolution were affected by post-colonization radiation is poorly understood. In collaboration with field biologists and bioinformaticians, this project therefore aims to de-novo assemble the genomes of seven tenrec species covering all phylogenetic and ecomorphological lineages. In addition, we aim to assemble the genomes of an otter shrew as closest relative to tenrecs and a semi-aquatic eulipotyphlan shrew to complement our extensive comparative genomic sample. By combining state-of-the-art PacBio Hifi long-read sequencing technologies and recently developed in-silico mate-pair approaches, we propose a comprehensive yet cost-effective approach that will enable us (I) to reconstruct the phylogenomic history of Malagasy tenrecs; (II) to compare the rates of morphological evolution along the phylogenomic tree of tenrecs; and (III) to identify genome-wide molecular convergence/parallelism among Malagasy tenrecs and Laurasian insectivorans (shrews, moles, hedgehogs). To overcome the pitfalls of previous candidate-based convergence analyses, we will implement a genome-wide, functionally agnostic approach that will take background convergence into account and that seeks for convergent effects on tissues and organs rather than on individual genes. Altogether, the results are expected to provide novel insights into the evolutionary processes that shaped the diversity. They will further help to elucidate how phenotypic convergence is paralleled by molecular convergence and shifts in morphological rates among mammals.

• DFG Programme: Research Grants
• Co-Investigator: Professor Dr. Michael Hiller