Geographical distribution and diversification of small mammals in sub-Saharan Africa: integration of fossil and modern data

Abstract

This communication aims to present a French-Czech collaboration project initiated in 2021 within the framework of a Hubert Curien Partnership (PHC) "Barrande", which focuses on the study of East African small mammals. Ethiopia in particular has very rich and specific rodent fauna. Moreover, if considered in a wider pan-African and phylogenetic context, the region also appears as the “cradle” of some of these taxa, which have then radiated in the course of their expansion to the rest of the continent. Ethiopia has also played the role of a biogeographic crossroad by uniting Middle East faunas to North African and sub Saharan ones. The deeper study of biodiversity thus requires not only classification into species, but also estimates of their phylogeny and evolutionary history. It also require a good knowledge of fossil taxa history through time in order to place diversification process at the light of climatic and tectonic changes. In this project we use an integrative approach combining genetic data (inference of complete and robust phylogenies, inference of demographic processes, phylogeography and population genetics), morphometric data (obtained on both modern and Quaternary fossil specimens) and ecological niche modelling data (niche conservatism versus adaptive divergence). This integrative approach will allow us to better understand evolutionary processes that have led to the diversification of African small mammals. It will also allow us to answer key question in evolutionary biology, such as the role of geo-climatic changes on diversification and extinction processes, how morphological and genetics changes vary through time and the mechanisms of speciation. A preliminary study on the Goda Buticha Pleistocene-Holocene site of eastern Ethiopia has also shown the importance of a good knowledge of modern taxa and of the constitution of robust referentials for the reliable identification of fossil specimens at the specific level. Our results wil