Evolutionary history of the thicket rats (genus Grammomys) mirrors the evolution of African forests since late Miocene

Abstract

Aim Grammomys are mostly arboreal rodents occurring in forests, woodlands and thickets throughout sub‐Saharan Africa. We investigated whether the divergence events within the genus follow the existing evolutionary scenario for the development of African forests since the late Miocene. Location Sub‐Saharan African forests and woodlands. Methods We inferred the molecular phylogeny of Grammomys using Bayesian and maximum likelihood methods and DNA sequences of 351 specimens collected from across the distribution of the genus. We mapped the genetic diversity, estimated the divergence times by a relaxed clock model and compared evolution of the genus with forest history. Results Phylogenetic analysis confirms the monophyly of Grammomys and reveals five main Grammomys lineages with mainly parapatric distributions: (1) the poensis group in Guineo‐Congolese forests; (2) the selousi group with a distribution mainly in coastal forests of southern and eastern Africa; (3) the dolichurus group restricted to the easternmost part of South Africa; (4) the macmillani group in the northern part of eastern and Central Africa with one isolated species in Guinean forests; and (5) the surdaster group, widely distributed in eastern Africa south of the equator. Every group contains well supported sublineages suggesting the existence of undescribed species. The earliest split within the genus (groups 1 vs. 2–5) occurred in the late Miocene and coincides with the formation of the Rift Valley which resulted in the east–west division of the initially pan‐African forest. The subsequent separation between groups (2 vs. 3–5) also dates to the end of the Miocene and suggests the split between Grammomys from coastal to upland forests in eastern Africa followed by a single dispersal event into western Africa during the Pleistocene. Conclusions The evolutionary history of the genus Grammomys closely reflects the accepted scenario of major historical changes in the distribution of tropical African forests since the late Miocene.

Genetic variation of the most abundant forest‐dwelling rodents in Central Africa (Praomys jacksoni complex): Evidence for Pleistocene refugia in both montane and lowland forests

“…Similar to other mammals (Bryja et al., ; Demos et al., , ) and plants (Droissart et al., ; Plumptre et al., ), our genetic analysis supports biogeographic affinities between ARM and KH. These two mountain massifs are currently separated by a 500 km wide gap without forest (‘Uganda gap’), which forms a filter corridor for small mammals restricted to humid montane habitats (Demos et al., ).…”

Molecular phylogenetic analyses indicate paraphyly of the genusHybomys(Rodentia: Muridae): Taxonomic implications

“…K2P cyt b genetic distances between members of these two species complexes (that vary from 15.6% between H. rufocanus and H. trivirgatus to 18.8% between H. rufocanus and H. planifrons ) are comparable to intergeneric distances between genera in the Arvicanthini tribe (that range from 15.1% between Pelomys and Mylomys to 25.93% between Mylomys and Stochomys ). Previous DNA sequence data also reported the close relationship between members of the univittatus species complex and the genera Dephomys and Stochomys (Bryja et al., ; Lecompte et al., ; Missoup et al., ). Misonne () and Van der Straeten () also emphasized the affinity between H. univittatus and Dephomys based on cranial and dental characters.…”

“…badius , respectively. Molecular genetic analyses are increasingly used to delimit species, particularly in rodents (Baker & Bradley, ; Bryja et al., , ; Granjon & Montgelard, ; Taylor et al., ). In the following paragraphs, we discuss the status of rufocanus and eisentrauti based on our DNA sequence data, and data from the literature.…”

“…However, the monophyly of several of these genera and the number of species within them is still a matter of controversy (e.g. Bryja et al., for the genus Grammomys ). This is especially true for the genus Hybomys Thomas, .…”

Multilocus phylogeny of the Crocidura poensis species complex (Mammalia, Eulipotyphla): Influences of the palaeoclimate on its diversification and evolution

“…Small terrestrial mammals, owing to their low dispersal ability, are excellent models for testing the patterns of pan‐African biogeography. There have been several large‐scale studies on sub‐Saharan rodents (Bohoussou et al., ; Bryja et al., ; Colangelo et al., ; Missoup et al., ; Nicolas, Mboumba, et al., ; Olayemi et al., ), but only one study was devoted to the pan‐African biogeography of shrews (Jacquet et al., ). The genus Crocidura is hyper‐diversified in Africa, with 109 recognized species (Happold & Happold, ).…”