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Humewood, South Africa

Medina M.F.,University of Texas at El Paso | Bauer A.M.,Villanova University | Branch W.R.,Bayworld | Branch W.R.,Nelson Mandela Metropolitan University | And 12 more authors.
Molecular Phylogenetics and Evolution | Year: 2016

African snake-eyed skinks are relatively small lizards of the genera Panaspis and Afroablepharus. Species allocation of these genera frequently changed during the 20th century based on morphology, ecology, and biogeography. Members of these genera occur primarily in savanna habitats throughout sub-Saharan Africa and include species whose highly conserved morphology poses challenges for taxonomic studies. We sequenced two mitochondrial (16S and cyt b) and two nuclear genes (PDC and RAG1) from 76 Panaspis and Afroablepharus samples from across eastern, central, and southern Africa. Concatenated gene-tree and divergence-dating analyses were conducted to infer phylogenies and biogeographic patterns. Molecular data sets revealed several cryptic lineages, with most radiations occurring during the mid-Miocene to Pliocene. We infer that rifting processes (including the formation of the East African Rift System) and climatic oscillations contributed to the expansion and contraction of savannas, and caused cladogenesis in snake-eyed skinks. Species in Panaspis and Afroablepharus used in this study, including type species for both genera, formed a monophyletic group. As a result, the latter genus should be synonymized with the former, which has priority. Conservatively, we continue to include the West African species P. breviceps and P. togoensis within an expanded Panaspis, but note that they occur in relatively divergent clades, and their taxonomic status may change with improved taxon sampling. Divergence estimates and cryptic speciation patterns of snake-eyed skinks were consistent with previous studies of other savanna vertebrate lineages from the same areas examined in this study. © 2016 Elsevier Inc. Source


Tolley K.A.,South African National Biodiversity Institute | Tolley K.A.,Stellenbosch University | Tilbury C.R.,Stellenbosch University | Measey G.J.,South African National Biodiversity Institute | And 5 more authors.
Journal of Biogeography | Year: 2011

Aim East Africa is one of the most biologically diverse regions, especially in terms of endemism and species richness. Hypotheses put forward to explain this high diversity invoke a role for forest refugia through: (1) accumulation of new species due to radiation within refugial habitats, or (2) retention of older palaeoendemic species in stable refugia. We tested these alternative hypotheses using data for a diverse genus of East African forest chameleons, Kinyongia. Location East Africa. Methods We constructed a dated phylogeny for Kinyongia using one nuclear and two mitochondrial markers. We identified areas of high phylogenetic diversity (PD) and evolutionary diversity (ED), and mapped ancestral areas to ascertain whether lineage diversification could best be explained by vicariance or dispersal. Results Vicariance best explains the present biogeographic patterns, with divergence between three major Kinyongia clades (Albertine Rift, southern Eastern Arc, northern Eastern Arc) in the early Miocene/Oligocene (>20Ma). Lineage diversification within these clades pre-dates the Pliocene (>6Ma). These dates are much older than the Plio-Pleistocene climatic shifts associated with cladogenesis in other East African taxa (e.g. birds), and instead point to a scenario whereby palaeoendemics are retained in refugia, rather than more recent radiations within refugia. Estimates of PD show that diversity was highest in the Uluguru, Nguru and East Usambara Mountains and several lineages (from Mount Kenya, South Pare and the Uluguru Mountains) stand out as being evolutionarily distinct as a result of isolation in forest refugia. PD was lower than expected by chance, suggesting that the phylogenetic signal is influenced by an unusually low number of extant lineages with long branch lengths, which is probably due to the retention of palaeoendemic lineages. Main conclusions The biogeographic patterns associated with Kinyongia are the result of long evolutionary histories in isolation. The phylogeny is dominated by ancient lineages whose origins date back to the early Miocene/Oligocene as a result of continental wide forest fragmentation and contraction due to long term climatic changes in Africa. The maintenance of palaeoendemic lineages in refugia has contributed substantially to the remarkably high biodiversity of East Africa. © 2011 Blackwell Publishing Ltd. Source


Vidal N.,French Natural History Museum | Marin J.,French Natural History Museum | Morini M.,French Natural History Museum | Donnellan S.,South Australian Museum | And 7 more authors.
Biology Letters | Year: 2010

Worm-like snakes (scolecophidians) are small, burrowing species with reduced vision. Although largely neglected in vertebrate research, knowledge of their biogeographical history is crucial for evaluating hypotheses of snake origins. We constructed a molecular dataset for scolecophidians with detailed sampling within the largest family, Typhlopidae (blindsnakes). Our results demonstrate that scolecophidians have had a long Gondwanan history, and that their initial diversification followed a vicariant event: the separation of East and West Gondwana approximately 150 Ma. We find that the earliest blindsnake lineages, representing two new families described here, were distributed on the palaeolandmass of India + Madagascar named here as Indigascar. Their later evolution out of Indigascar involved vicariance and several oceanic dispersal events, including a westward transatlantic one, unexpected for burrowing animals. The exceptional diversification of scolecophidians in the Cenozoic was probably linked to a parallel radiation of prey (ants and termites) as well as increased isolation of populations facilitated by their fossorial habits. © 2010 The Royal Society. Source


Dalhuijsen K.,University of Witwatersrand | Branch W.R.,Bayworld | Branch W.R.,Nelson Mandela Metropolitan University | Alexander G.J.,University of Witwatersrand
African Zoology | Year: 2014

We present data from gut content analyses of Varanus albigularis (savanna monitor) and V. niloticus (water monitor) in South Africa. Both species are generalist, opportunistic feeders. We did not detect any sex-based differences in the diet of V. albigularis, and there were relatively high levels of dietary overlap between the species, although there were significant differences for certain prey types. These differences match differences in habitat use between the species: the more aquatic V. niloticus consumed aquatic prey, such as amphibians and crabs, more often than did V. albigularis. Varanus albigularis included more terrestrial prey such as diplopods in its diet. Tortoises and millipedes were also prominent in the V. albigularis diet, constituting an important component of dietary intake. Few of our samples from V. albigularis had empty stomachs, suggesting that this species may occupy a lower trophic level than its Australian counterparts. Although there is a large degree of overlap in the diets of the two species, there is a trend for V. albigularis to eat more slow-moving prey. These differences result in the species foraging at different trophic levels. Source


Greenbaum E.,University of Texas at El Paso | Villanueva C.O.,University of Texas at El Paso | Aristote M.M.,Institute Superieur Decologie Pour La Conservation Of La Nature | Branch W.R.,Bayworld | Branch W.R.,Nelson Mandela Metropolitan University
Zoological Journal of the Linnean Society | Year: 2011

Currently, four species of the lacertid lizard genus Adolfus are known from Central and East Africa. We sequenced up to 2825 bp of two mitochondrial [16S and cytochrome b (cyt b)] and two nuclear [(c-mos (oocyte maturation factor) and RAG1 (recombination activating gene 1)] genes from 41 samples of Adolfus (representing every species), two species each of Gastropholis and Holaspis, and in separate analyses combined these data with GenBank sequences of all other Eremiadini genera and four Lacertini outgroups. Data from DNA sequences were analysed with maximum parsimony (PAUP), maximum-likelihood (RAxML) and Bayesian inference (MrBayes) criteria. Results demonstrated that Adolfus is not monophyletic: Adolfus africanus (type species), Adolfus alleni, and Adolfus jacksoni are sister taxa, whereas Adolfus vauereselli and a new species from the Itombwe Plateau of Democratic Republic of the Congo are in a separate lineage. Holaspis and Gastropholis were recovered in separate clades. Based on these molecular data, relatively substantial sequence divergence, and multiple morphological differences, we describe a new genus of lacertid for the lineage including A. vauereselli and the new Itombwe species. The recognition of this new, endemic genus underscores the conservation importance of the Albertine Rift, especially the Itombwe Plateau, a unique region that is severely threatened by unchecked deforestation, mining, and poaching. © 2011 The Linnean Society of London. Source

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