Microbial Community Responses to Alterations in Historical Fire Regimes in Montane Grasslands
- Authors: Gokul, Jarishma K , Matcher, Gwynneth , Dames, Joanna F , Nkangala, Kuhle , Gordijn, Paul J , Barker, Nigel P
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440366 , vital:73777 , https://doi.org/10.3390/d15070818
- Description: The influence of fire regimes on soil microbial diversity in montane grasslands is a relatively unexplored area of interest. Understanding the belowground diversity is a crucial stepping-stone toward unravelling community dynamics, nutrient sequestration, and overall ecosystem stability. In this study, metabarcoding was used to unravel the impact of fire disturbance regimes on bacterial and arbuscular mycorrhizal fungal community structures in South African montane grasslands that have been subjected to an intermediate (up to five years) term experimental fire-return interval gradient. Bacterial communities in this study exhibited a shift in composition in soils subjected to annual and biennial fires compared to the controls, with carbon and nitrogen identified as significant potential chemical drivers of bacterial communities. Shifts in relative abundances of dominant fungal operational taxonomic units were noted, with Glomeromycota as the dominant arbuscular mycorrhiza observed across the fire-return gradient. A reduction in mycorrhizal root colonisation was also observed in frequently burnt autumnal grassland plots in this study. Furthermore, evidence of significant mutualistic interactions between bacteria and fungi that may act as drivers of the observed community structure were detected. Through this pilot study, we can show that fire regime strongly impacts bacterial and fungal communities in southern African montane grasslands, and that changes to their usually resilient structure are mediated by seasonal burn patterns, chemical drivers, and mutualistic interactions between these two groups.
- Full Text:
- Date Issued: 2023
Coastal dunefields maintain pre‐Holocene genetic structure in a rocky shore red alga
- Authors: Mmonwa, Kolobe L , Barker, Nigel P , McQuaid, Christopher D , Teske, Peter R
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444784 , vital:74298 , https://doi.org/10.1111/jpy.13182
- Description: Most intertidal algae have limited dispersal potential, and areas that lack hard substratum suitable for attachment are thus expected to isolate regional populations from each other. Here, we used nuclear and mitochondrial genetic data to compare genetic structure in two co‐distributed intertidal red algae with different dispersal potential along the South African coastline. Gelidium pristoides is divided into a south‐eastern and a south‐western evolutionary lineage separated by extensive, continuous sandy shoreline habitat adjacent to coastal dunefields. In contrast, Hypnea spicifera is genetically homogeneous throughout its range. In G. pristoides, the genetic breaks are associated with contemporary coastal dunefields. The age of the divergence event suggests that this may reflect the effect of older dispersal barriers, and that genetic structure was subsequently maintained by the formation of contemporary coastal dunefields.
- Full Text:
- Date Issued: 2021
Biomes, geology and past climate drive speciation of laminate-toothed rats on South African mountains (Murinae: Otomys)
- Authors: Taylor, Peter J , Kearney, Theresa , Dalton, Desire L , Chakona, Gamuchirai , Kelly, Christopher M R , Barker, Nigel P
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/453158 , vital:75227 , xlink:href="https://doi.org/10.1093/zoolinnean/zlz134"
- Description: Mitochondrial DNA sequences (1137 bp) of the cytochrome b gene and craniodental and craniometric data were used to investigate the evolutionary relationships of six putative rodent taxa of Otomys (family Muridae: subfamily Murinae: tribe Otomyini) co-occurring in the Western Cape and Eastern Cape provinces of South Africa. Phylogenetic analysis of 20 new sequences together with craniodental and craniometric characters of 94 adult skulls reveal the existence of a unique lineage of Otomys cf. karoensis (named herein Otomys willani sp. nov.) from the Sneeuberg Centre of Floristic Endemism in the southern Drakensberg Mountain Range. Craniometric analysis distinguished O. karoensis from O. willani and identified a further four localities in the range of the latter species. We document southern range extensions of both Sloggett’s ice rat, Otomys sloggetti, and the vlei rat Otomys auratus to the Sneeuberg Mountain Range, in addition to appreciable genetic divergence between Sneeuberg and southern and central Drakensberg populations of O. sloggetti. Our results demonstrate parallel patterns of cryptic speciation in two co-occurring species complexes (Otomys irroratus s.l. and O. karoensis s.l.) associated closely with the boundaries of biomes (fynbos vs. grassland biomes) and geological formations (Cape Fold Belt vs. Great Escarpment).
- Full Text:
- Date Issued: 2020
Biomes, geology and past climate drive speciation of laminate-toothed rats on South African mountains (Murinae: Otomys)
- Authors: Taylor, Peter J , Kearney, Theresa , Dalton, Desire L , Chakona, Gamuchirai , Kelly, Christopher M R , Barker, Nigel P
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/425481 , vital:72249 , xlink:href="https://doi.org/10.1093/zoolinnean/zlz134"
- Description: Mitochondrial DNA sequences (1137 bp) of the cytochrome b gene and craniodental and craniometric data were used to investigate the evolutionary relationships of six putative rodent taxa of Otomys (family Muridae: subfamily Murinae: tribe Otomyini) co-occurring in the Western Cape and Eastern Cape provinces of South Africa. Phylogenetic analysis of 20 new sequences together with craniodental and craniometric characters of 94 adult skulls reveal the existence of a unique lineage of Otomys cf. karoensis (named herein Otomys willani sp. nov.) from the Sneeuberg Centre of Floristic Endemism in the southern Drakensberg Mountain Range. Craniometric analysis distinguished O. karoensis from O. willani and identified a further four localities in the range of the latter species. We document southern range extensions of both Sloggett’s ice rat, Otomys sloggetti, and the vlei rat Otomys auratus to the Sneeuberg Mountain Range, in addition to appreciable genetic divergence between Sneeuberg and southern and central Drakensberg populations of O. sloggetti. Our results demonstrate parallel patterns of cryptic speciation in two co-occurring species complexes (Otomys irroratus s.l. and O. karoensis s.l.) associated closely with the boundaries of biomes (fynbos vs. grassland biomes) and geological formations (Cape Fold Belt vs. Great Escarpment).
- Full Text:
- Date Issued: 2020
Habitat requirements affect genetic variation in three species of mayfly (Ephemeroptera, Baetidae) from South Africa:
- Authors: Taylor, Chantal L , Barker, Nigel P , Barber-James, Helen M , Villet, Martin H , Pereira-da-Conceicoa, Lyndall L
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149314 , vital:38824 , https://doi.org/10.3897/zookeys.936.38587
- Description: This study investigates genetic diversity in three species of Ephemeroptera, one eurytopic and therefore widespread (Afroptilum sudafricanum) and two stenotopic and thus endemic (Demoreptus natalensis and Demoreptus capensis) species, all of which co-occur in the southern Great Escarpment, South Africa. Mitochondrial DNA was analysed to compare the genetic diversity between the habitat generalist and the two habitat specialists. Afroptilum sudafricanum showed no indication of population genetic structure due to geographic location, while both Demoreptus species revealed clear genetic differentiation between geographic localities and catchments, evident from phylogenetic analyses and high FST values from AMOVA.
- Full Text:
- Date Issued: 2020
Intraspecific mitochondrial gene variation can be as low as that of nuclear rRNA:
- Authors: Matumba, Tshifhiwa G , Oliver, Jody , Barker, Nigel P , McQuaid, Christopher D , Teske, Peter R
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160401 , vital:40442 , https://doi.org/10.12688/f1000research.23635.2
- Description: Mitochondrial DNA (mtDNA) has long been used to date historical demographic events. The idea that it is useful for molecular dating rests on the premise that its evolution is neutral. Even though this idea has long been challenged, the evidence against clock-like evolution of mtDNA is often ignored. Here, we present a particularly clear and simple example to illustrate the implications of violations of the assumption of selective neutrality.
- Full Text:
- Date Issued: 2020
Out of Africa?: a dated molecular phylogeny of the cicada tribe Platypleurini Schmidt (Hemiptera: Cicadidae), with a focus on African genera and the genus Platypleura Amyot and Audinet‐Serville
- Authors: Price, Benjamin W , Marshall, David C , Barker, Nigel P , Simon, Chris , Villet, Martin H
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/140704 , vital:37911 , DOI: 10.1111/syen.12360
- Description: The Platypleurini is a large group of charismatic cicadas distributed from Cape Agulhas in South Africa, through tropical Africa, Madagascar, India and eastern Asia to Japan, with generic diversity concentrated in equatorial and southern Africa. This distribution suggests the possibility of a Gondwanan origin and dispersal to eastern Asia from Africa or India. We used a four-gene (three mitochondrial) molecular dataset, fossil calibrations and molecular clock information to explore the phylogenetic relationships of the platypleurine cicadas and the timing and geography of their diversification. The earliest splits in the tribe were found to separate forest genera in Madagascar and equatorial Africa from the main radiation, and all of the Asian/Indian species sampled formed a younger clade nested well within the African taxa.
- Full Text:
- Date Issued: 2019
Evolution of foraging behaviour: Deep intra-generic genetic divergence between territorial and non-territorial southern African patellid limpets
- Authors: Mmonwa, Kolobe L , Teske, Peter R , McQuaid, Christopher D , Barker, Nigel P
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444798 , vital:74299 , https://doi.org/10.1016/j.ympev.2017.05.024
- Description: Southern Africa is a biodiversity hotspot of patellid limpets, with three genera (Helcion, Cymbula and Scutellastra) identified and described in the region. Scutellastra is the most diverse and most frequently studied of these and, along with Cymbula, includes species with territorial and non-territorial foraging behaviours. We used three mitochondrial markers (12S rRNA, 16S rRNA and COI) and one nuclear marker (ATPSβ intron) to assess evolutionary relationships among species of Cymbula and Scutellastra with these two foraging behaviours and to identify which foraging mode is the more ancient. Maximum Likelihood and Bayesian Inference phylogenetic analyses revealed that the species sharing a foraging type are monophyletic in both genera. Territoriality is a derived character, as the clades with this foraging type are nested within a tree that otherwise comprises non-territorial taxa. These include Helcion, which was recovered as sister to the Cymbula/Scutellastra clade, and the next basal genus, Patella, which is ancestral to all southern African patellogastropods. Deep genetic divergence between the two foraging traits reflects strong adaptive effects of resource partitioning in the evolution of southern African patellid limpets.
- Full Text:
- Date Issued: 2017
Historical demography of southern African patellid limpets: congruence of population expansions, but not phylogeography
- Authors: Mmonwa, Kolobe L , Teske, Peter R , McQuaid, Christopher D , Barker, Nigel P
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444814 , vital:74300 , https://doi.org/10.2989/1814232X.2015.1009165
- Description: Global climatic oscillations have shaped the contemporary genetic structure of marine taxa in different ways. Previous demographic studies have indicated that various intertidal marine species display genetic signatures of demographic expansion that either pre- or postdate the Last Glacial Maximum. Such expansions and the ability of species to colonise new habitats will influence their genetic structure, but the link between scales of larval dispersal and the strength of phylogeographic structure is not always clear. We analysed a fragment of the mitochondrial COI gene of 11 sympatric species of intertidal southern African patellid limpets to investigate how ancient oceanographic dynamics have shaped and maintained their contemporary spatial genetic variation. Our data show that the patellid limpets investigated display congruent evidence of spatial expansion during the Late Pleistocene or Early Holocene, which corresponds with the establishment of the contemporary southern African shoreline. We argue that closely related and co-distributed southern African intertidal invertebrates responded to ancient climatic oscillations as a cohesive group. In contrast, contemporary oceanographic circulation has shaped the phylogeographic patterns of these limpets in different ways. We show close relationships between phylogeography and biogeography for some species, but not for others, despite the similarities in their life histories and exposure to the same climatic changes.
- Full Text:
- Date Issued: 2015
Mitonuclear discordance in genetic structure across the Atlantic/Indian Ocean biogeographical transition zone
- Authors: Teske, Peter R , Papadopoulos, Isabelle , Barker, Nigel P , McQuaid, Christopher D , Beheregaray, Luciano B
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444832 , vital:74301 , https://doi.org/10.1111/jbi.1220
- Description: Based on mitochondrial DNA (mtDNA) data, many organisms with ranges spanning multiple biogeographical regions exhibit genetic structure across the transition zones between these regions, while others appear to be genetically homogenous. No clear link has been found between the presence or absence of such spatial genetic discontinuities and species' dispersal potential, confounding the formulation of general predictions concerning genetic structure. The fact that discrepancies between mtDNA and nuclear markers are common across semi‐permeable barriers suggests that a lack of structure could be attributable to mtDNA‐specific properties of inheritance. We re‐examined genetic structure in the coastal crab Hymenosoma orbiculare, a species that is represented by a single mtDNA lineage across the Atlantic/Indian Ocean biogeographical transition zone, by comparing mtDNA data with nuclear DNA data.
- Full Text:
- Date Issued: 2014
Dispersal barriers and stochastic reproductive success do not explain small-scale genetic structure in a broadcast spawning marine mussel
- Authors: Teske, Peter R , Papadopoulos, Isabelle , Barker, Nigel P , McQuaid, Christopher D
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/445577 , vital:74403 , https://doi.org/10.3354/meps10230
- Description: Small-scale genetic heterogeneity in marine broadcast spawners is often attributed either to physical factors that constrain larval dispersal or to stochasticity in reproductive success. In females of the mussel Perna perna, it has been attributed to asymmetrical levels of gene flow between bays and the open coast, with bays acting as sources of propagules. If nearshore currents are an important feature constraining dispersal, then genetic heterogeneity should also be identified in other coastal invertebrates with similar dispersal potential, and the amount of genetic structure in adults and juveniles should be similar, whereas temporal changes in reproductive success should manifest themselves in lower genetic diversity of juveniles. We compared sequence data of female P. perna with that of males, juveniles and 3 sympatric marine invertebrates. Congruent genetic structure was only found in a direct developer, suggesting that the region’s oceanography does not have a strong structuring effect on species that, like female P. perna, have a planktonic dispersal phase. Furthermore, lack of genetic structure in male and juvenile P. perna indicates that there are no physical barriers that reduce larval exchange. Stochastic reproductive success is also an unlikely explanation for genetic structure in P. perna because levels of genetic diversity are similar in adults and juveniles. Together with the recent finding that the sex ratio in P. perna is skewed toward males, particularly at exposed coastal sites, these results point to a role for selection in driving genetic structure between bays and coastal habitats by eliminating a large proportion of adult females from the open coast.
- Full Text: false
- Date Issued: 2013
Identification of a uniquely southern African clade of coastal pipefishes Syngnathus spp.
- Authors: Mwale, Monica , Kaiser, Horst , Barker, Nigel P , Wilson, A B , Teske, Peter R
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/445499 , vital:74393 , https://doi.org/10.1111/jfb.12130
- Description: The taxonomic status of two southern African coastal pipefish species, Syngnathus temminckii and Syngnathus watermeyeri, was investigated using a combination of morphological and genetic data. Morphological data showed that S. temminckii is distinct from the broadly distributed European pipefish Syngnathus acus, and a molecular phylogeny reconstructed using mitochondrial DNA recovered S. temminckii and S. watermeyeri as sister taxa. The southern African species share an evolutionary origin with north‐eastern Atlantic Ocean and Mediterranean Sea species, including S. acus. These data support the existence of a distinct southern African clade of Syngnathus pipefishes that has diverged in situ to form the two species present in the region today.
- Full Text:
- Date Issued: 2013
Rules of attraction: the role of bait in small mammal sampling at high altitude in South Africa
- Authors: Kok, Armand D , Parker, Daniel M , Barker, Nigel P
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/443936 , vital:74173 , https://doi.org/10.1080/15627020.2013.11407571
- Description: Baits or lures are commonly used for surveying small mammal communities, not only because they attract large numbers of these animals, but also because they provide sustenance for trapped individuals. In this study we used Sherman live traps with five bait treatments to sample small mammal populations at three high-altitude sites (>1700 m) in the Sneeuberg Mountain Complex of the Eastern Cape Province, South Africa.We investigated the influence of bait treatment on three parameters commonly recorded in small mammal surveys. In addition, we investigated how different bait treatments vary in measuring species richness using the Chao 2 species richness estimator together with rarefaction curves. Overall, 12 small mammal species were sampled. A combination of birdseed and banana captured the highest number of species (11) but the most successful bait overall was peanut butter and oats (greatest number of captures, recaptures, number of individuals and highest Shannon diversity). The Chao 2 richness estimator indicated that four of the five bait treatments reached their sampling capacity. Rarefaction curves indicated that all bait treatments are similar with regard to species accumulation. This could possibly be explained by odours left behind in traps as even un-baited traps (i.e. controls) captured seven different small mammal species. We conclude that the most suitable bait for surveying small mammals at high altitude in South Africa is peanut butter and oats. However, using peanut butter and oats in combination with other bait treatments will improve estimates of diversity when surveying small mammal communities.
- Full Text:
- Date Issued: 2013
Cryptic variation in an ecological indicator organism: mitochondrial and nuclear DNA sequence data confirm distinct lineages of Baetis harrisoni Barnard (Ephemeroptera: Baetidae) in Southern Africa
- Authors: Pereira-da-Conceicoa, Lyndall L , Price, Benjamin W , Barber-James, Helen M , Barker, Nigel P , de Moor, Ferdy C , Villet, Martin H
- Date: 2012
- Language: English
- Type: Article
- Identifier: vital:6535 , http://hdl.handle.net/10962/d1005976 , https://dx.doi.org/10.1186/1471-2148-12-26
- Description: Baetis harrisoni Barnard is a mayfly frequently encountered in river studies across Africa, but the external morphological features used for identifying nymphs have been observed to vary subtly between different geographic locations. It has been associated with a wide range of ecological conditions, including pH extremes of pH 2.9–10.0 in polluted waters. We present a molecular study of the genetic variation within B. harrisoni across 21 rivers in its distribution range in southern Africa.
- Full Text:
- Date Issued: 2012
Mitochondrial DNA paradox: sex-specific genetic structure in a marine mussel despite maternal inheritance and passive dispersal
- Authors: Teske, Peter R , Papadopoulos, Isabelle , Barker, Nigel P , McQuaid, Christopher D
- Date: 2012
- Language: English
- Type: Article
- Identifier: vital:6836 , http://hdl.handle.net/10962/d1010959
- Description: Background: When genetic structure is identified using mitochondrial DNA (mtDNA), but no structure is identified using biparentally-inherited nuclear DNA, the discordance is often attributed to differences in dispersal potential between the sexes. Results: We sampled the intertidal rocky shore mussel Perna perna in a South African bay and along the nearby open coast, and sequenced maternally-inherited mtDNA (there is no evidence for paternally-inherited mtDNA in this species) and a biparentally-inherited marker. By treating males and females as different populations, we identified significant genetic structure on the basis of mtDNA data in the females only. Conclusions: This is the first study to report sex-specific differences in genetic structure based on matrilineally-inherited mtDNA in a passively dispersing species that lacks social structure or sexual dimorphism. The observed pattern most likely stems from females being more vulnerable to selection in habitats from which they did not originate, which also manifests itself in a male-biased sex ratio. Our results have three important implications for the interpretation of population genetic data. First, even when mtDNA is inherited exclusively in the female line, it also contains information about males. For that reason, using it to identify sex-specific differences in genetic structure by contrasting it with biparentally-inherited markers is problematic. Second, the fact that sex-specific differences were found in a passively dispersing species in which sex-biased dispersal is unlikely highlights the fact that significant genetic structure is not necessarily a function of low dispersal potential or physical barriers. Third, even though mtDNA is typically used to study historical demographic processes, it also contains information about contemporary processes. Higher survival rates of males in non-native habitats can erase the genetic structure present in their mothers within a single generation.
- Full Text:
- Date Issued: 2012
"Nested" cryptic diversity in a widespread marine ecosystem engineer: a challenge for detecting biological invasions
- Authors: Teske, Peter R , Ruis, Marc , McQuaid, Christopher D , Styan, Craig A , Piggott, Maxine P , Benhissoune, Saïd , Fuentes-Grünewald, Claudio , Walls, Kathy , Page, Mike , Attard, Catherine R M , Cooke, Georgina M , McClusky, Claire F , Banks, Sam C , Barker, Nigel P , Beheregaray, Luciano B
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/445529 , vital:74396 , https://doi.org/10.1186/1471-2148-11-176
- Description: Ecosystem engineers facilitate habitat formation and enhance biodiversity, but when they become invasive, they present a critical threat to native communities because they can drastically alter the receiving habitat. Management of such species thus needs to be a priority, but the poorly resolved taxonomy of many ecosystem engineers represents a major obstacle to correctly identifying them as being either native or introduced. We address this dilemma by studying the sea squirt Pyura stolonifera, an important ecosystem engineer that dominates coastal communities particularly in the southern hemisphere. Using DNA sequence data from four independently evolving loci, we aimed to determine levels of cryptic diversity, the invasive or native status of each regional population, and the most appropriate sampling design for identifying the geographic ranges of each evolutionary unit.
- Full Text:
- Date Issued: 2011
A review of marine phylogeography in southern Africa
- Authors: Teske, Peter R , von der Heyden, Sophie , McQuaid, Christopher D , Barker, Nigel P
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/445392 , vital:74382 , https://hdl.handle.net/10520/EJC97146
- Description: The southern African marine realm is located at the transition zone between the Atlantic and Indo-Pacific biomes. Its biodiversity is particularly rich and comprises faunal and floral elements from the two major oceanic regions, as well as a large number of endemics. Within this realm, strikingly different biota occur in close geographic proximity to each other, and many of the species with distributions spanning two or more of the region's marine biogeographic provinces are divided into evolutionary units that can often only be distinguished on the basis of genetic data. In this review, we describe the state of marine phylogeography in southern Africa, that is, the study of evolutionary relationships at the species level, or amongst closely related species, in relation to the region's marine environment. We focus particularly on coastal phylogeography, where much progress has recently been made in identifying phylogeographic breaks and explaining how they originated and are maintained. We also highlight numerous shortcomings that should be addressed in the near future. These include: the limited data available for commercially important organisms, particularly offshore species; the paucity of oceanographic data for nearshore areas; a dearth of studies based on multilocus data; and the fact that studying the role of diversifying selection in speciation has been limited to physiological approaches to the exclusion of genetics. It is becoming apparent that the southern African marine realm is one of the world's most interesting environments in which to study the evolutionary processes that shape not only regional, but also global patterns of marine biodiversity.
- Full Text:
- Date Issued: 2011
Climate‐driven genetic divergence of limpets with different life histories across a southeast African marine biogeographic disjunction: different processes, same outcome
- Authors: Teske, Peter R , Papadopoulos, Isabelle , Mmonwa, Kolobe L , Matumba, Tshifhiwa G , McQuaid, Christopher D , Barker, Nigel P , Beheregaray, Luciano B
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/445420 , vital:74385 , https://doi.org/10.1111/j.1365-294X.2011.05307.x
- Description: Genetic divergence among populations of marine broadcast spawners in the absence of past geological barriers presents an intriguing challenge to understanding speciation in the sea. To determine how differences in life history affect genetic divergence and demographic histories across incomplete dispersal barriers, we conducted a comparative phylogeographic study of three intertidal limpets (Siphonaria spp.) represented on either side of a biogeographic disjunction separating tropical and subtropical marine provinces in southeastern Africa. Using a combination of mitochondrial and nuclear sequence data, we identified two distinct evolutionary lineages each in both Siphonaria concinna (a planktonic disperser) and S. nigerrima (a direct developer), and panmixia in a second planktonic disperser, S. capensis.
- Full Text:
- Date Issued: 2011
Molecular systematics of the African snake family Lamprophiidae Fitzinger, 1843 (Serpentes: Elapoidea), with particular focus on the genera Lamprophis Fitzinger 1843 and Mehelya Csiki 1903
- Authors: Kelly, Christopher M R , Branch, William R , Broadley, Donald G , Barker, Nigel P , Villet, Martin H
- Date: 2011
- Language: English
- Type: Article
- Identifier: vital:6861 , http://hdl.handle.net/10962/d1011151
- Description: The snake family Lamprophiidae Fitzinger (Serpentes: Elapoidea) is a putatively Late Eocene radiation of nocturnal snakes endemic to the African continent. It incorporates many of the most characteristic and prolific of Africa's non-venomous snake species, including the widespread type genus Lamprophis Fitzinger, 1843 (house snakes). We used approximately 2500 bases of mitochondrial and nuclear DNA sequence data from 28 (41%) of the approximately 68 recognised lamprophiid species in nine of the eleven genera to investigate phylogenetic structure in the family and to inform taxonomy at the generic level. Cytochrome b, ND4 and tRNA gene sequences (mitochondrial) and c-mos sequences (nuclear) were analysed using Maximum Likelihood, Bayesian Inference and Maximum Parsimony methods. The genus Mehelya Csiki, 1903 was paraphyletic with respect to Gonionotophis Boulenger, 1893. To address this, the concept of Gonionotophis is expanded to include all current Mehelya species. The genus Lamprophis emerged polyphyletic: the enigmatic Lamprophis swazicus was sister to Hormonotus modestus from West Africa, and not closely related to its nominal congeners. It is moved to a new monotypic genus (Inyoka gen. nov.). The remaining Lamprophis species occur in three early-diverging lineages. (1) Lamprophis virgatus and the widely distributed Lamprophis fuliginosus species complex (which also includes Lamprophis lineatus and Lamprophis olivaceus) formed a clade for which the generic name Boaedon Duméril, Bibron & Duméril, 1854 is resurrected. (2) The water snakes (Lycodonomorphus) were nested within Lamprophis (sensu lato), sister to Lamprophis inornatus. We transfer this species to the genus Lycodonomorphus Fitzinger, 1843. (3) We restrict Lamprophis (sensu strictissimo) to a small clade of four species endemic to southern Africa: the type species of Lamprophis Fitzinger, 1843 (Lamprophis aurora) plus Lamprophis fiskii, Lamprophis fuscus and Lamprophis guttatus.
- Full Text:
- Date Issued: 2011
Psoralea margaretiflora (Psoraleeae, Fabaceae): a new species from the Sneeuberg Centre of Floristic Endemism, Eastern Cape, South Africa
- Authors: Stirton, Charles H , Clark, Vincent Ralph , Barker, Nigel P , Muasya, A Muthama
- Date: 2011
- Language: English
- Type: Article
- Identifier: vital:6543 , http://hdl.handle.net/10962/d1005999
- Description: A new species of Psoralea is described. Psoralea margaretiflora C.H. Stirton & V.R. Clark is endemic to the Sneeuberg Centre of Floristic Endemism, Eastern Cape, South Africa. This resprouter is characterised by its small greenish-white flowers with a small trifid purple nectar patch and translucent veins; 5(–7)-pinnate leaflets; multi-branching erect short seasonal flowering shoots; and tall habit of many stiff bare stems with the seasonal shoots massed at the apex. It is most similar to P. oligophylla Eckl. & Zeyh., a widespread species found in the Eastern Cape. The reseeder P. oligophylla differs in its lax virgate spreading habit with numerous long glaucous seasonal shoots; single stem, 1(–3)- glaucous leaflets; more numerous white flowers; and standard petals with a purple ring surrounding a bright yellow nectar patch.
- Full Text:
- Date Issued: 2011