Taxonomic revision and evolutionary history of the climbing mice in eastern Africa (Dendromus mystacalis clade): the role of elevation and geographical barriers in the speciation process

Abstract

There is increasing evidence that the Ethiopian highlands have functioned as a long-term refugium for many montane taxa. They also served as a source of colonization for other mountain blocks in eastern Africa during warm and humid Plio-Pleistocene episodes. The climbing mice (Dendromus) are widely distributed in grassy habitats across most African mountain regions, making them a suitable model to investigate how climate and topography have impacted the evolution of diversity in the Eastern Afromontane Biodiversity Hotspot. A recent phylogenetic study based mostly on mitochondrial DNA sequences identified a monophyletic Dendromus clade that grouped all known Ethiopian taxa plus two lineages outside Ethiopia. However, the species limits in this group, phylogenetic relationships, and biogeography remained unresolved. Here, we analyse the genomic variability at thousands of double-digest restriction-site-associated DNA (ddRAD) loci, sequences of the mitochondrial gene for cytochrome b, and morphological data from all major phylogenetic lineages in this clade, sampled from across their known distribution ranges, with an aim to delimit species and assess their distribution and evolutionary history. Both nuclear and mitochondrial phylogenies provide congruent results, i.e. the presence of seven well-supported major lineages (putative species), which are morphologically and ecologically distinguishable. We also provide a taxonomic revision (including sequencing of the mitogenome of the holotype of D. mystacalis) that resulted in the re-description of D. mystacalis, the description of two new species, and the resurrection of one species from synonymy. The most likely evolutionary scenario included a radiation in the Ethiopian highlands, followed by an "out-of-Ethiopia" dispersal event of a montane lineage, leading to the colonization of Imatong Mts. and Mt. Kilimanjaro.

Keywords

ddRAD; Cytochrome b; Ethiopian highlands; Phylogeography; Rodents; Taxonomic revision; Nesomyidae

Published in

Organisms Diversity and Evolution
2024
Publisher: SPRINGER HEIDELBERG

SLU Authors

• Meheretu, Yonas

  • Department of Wildlife, Fish and Environmental Studies, Swedish University of Agricultural Sciences
    
  • Mekelle University

UKÄ Subject classification

Zoology
Evolutionary Biology

Publication identifier

• DOI: https://doi.org/10.1007/s13127-024-00659-6

Permanent link to this page (URI)

https://res.slu.se/id/publ/133137