Patterns and processes underlying genetic diversity in the Namaqua rock mouse Micaelamys namaquensis Smith, 1834 (Rodentia : Muridae) from southern Africa
type: CreativeWork
description: African rock rats of the genera Aethomys Thomas, 1915 and Micaelamys Ellerman, 1941, are endemic to East, Central and southern Africa but extend marginally into West Africa. In the past 16 subspecies have been described in the Namaqua rock mouse M. namaquensis Smith, 1834. Recent morphometric and morphological patterns of intraspecific variation suggested the recognition of only four subspecies: M. n. namaquensis, M. n. alborarius, M. n. monticularis and M. n. lehocla, of which the distributions appeared to coincide with the major phytogeographical zones of southern Africa. In the present study earlier analyses of mitochondrial DNA (mtDNA) cytochrome b (cyt b) gene variation were extended. Taken together these results show that M. namaquensis represents a polytypic species complex but with much more diversity than detected using morphology. Phylogenetic and phylogeographic analyses revealed 14 genetically distinct lineages of which several show strong geographic association with particular vegetation biomes or bioregions. The distributional ranges of eight of these lineages showed some correspondence with the type localities of previously described subspecies of M. namaquensis. Some clades displayed considerable within-lineage variation indicating possible fine-scale population structuring, while others showed very little differentiation. Divergence times between lineages varied between 7.26 MYA and 2.70 MYA, corresponding to a Late Miocene to Pliocene radiation. Cytochrome b sequences alone do not fully resolve the evolutionary relationships among the lineages and the phylogenetic analysis was thus supplemented with nuclear Recombination Activating Gene 1 (RAG1) sequences. This gene was successfully sequenced for 11 of the identified lineages. Independent analyses of the two genes were not congruent possibly as a result of incomplete lineage sorting of the nuclear gene. The combined dataset yielded good support for six of the lineages. Finally, a more detailed phyl…
abstract: African rock rats of the genera Aethomys Thomas, 1915 and Micaelamys Ellerman, 1941, are endemic to East, Central and southern Africa but extend marginally into West Africa. In the past 16 subspecies have been described in the Namaqua rock mouse M. namaquensis Smith, 1834. Recent morphometric and morphological patterns of intraspecific variation suggested the recognition of only four subspecies: M. n. namaquensis, M. n. alborarius, M. n. monticularis and M. n. lehocla, of which the distributions appeared to coincide with the major phytogeographical zones of southern Africa. In the present study earlier analyses of mitochondrial DNA (mtDNA) cytochrome b (cyt b) gene variation were extended. Taken together these results show that M. namaquensis represents a polytypic species complex but with much more diversity than detected using morphology. Phylogenetic and phylogeographic analyses revealed 14 genetically distinct lineages of which several show strong geographic association with particular vegetation biomes or bioregions. The distributional ranges of eight of these lineages showed some correspondence with the type localities of previously described subspecies of M. namaquensis. Some clades displayed considerable within-lineage variation indicating possible fine-scale population structuring, while others showed very little differentiation. Divergence times between lineages varied between 7.26 MYA and 2.70 MYA, corresponding to a Late Miocene to Pliocene radiation. Cytochrome b sequences alone do not fully resolve the evolutionary relationships among the lineages and the phylogenetic analysis was thus supplemented with nuclear Recombination Activating Gene 1 (RAG1) sequences. This gene was successfully sequenced for 11 of the identified lineages. Independent analyses of the two genes were not congruent possibly as a result of incomplete lineage sorting of the nuclear gene. The combined dataset yielded good support for six of the lineages. Finally, a more detailed phyl…
keywords: Namaqua rock mouse (Micaelamys namaquensis), UCTD
date published: 2010-10-07
date modified: 2026-07-24T03:52:40Z
provider: University of Pretoria
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Pretoria

PropertyValue
property ID: Handle
value: http://hdl.handle.net/2263/28519