6 results on '"Penner, Johannes"'
Search Results
2. Rivers, not refugia, drove diversification in arboreal, sub‐Saharan African snakes.
- Author
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Allen, Kaitlin E., Greenbaum, Eli, Hime, Paul M., Tapondjou N., Walter P., Sterkhova, Viktoria V., Kusamba, Chifundera, Rödel, Mark‐Oliver, Penner, Johannes, Peterson, A. Townsend, and Brown, Rafe M.
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LAST Glacial Maximum ,RAIN forests ,SNAKES ,GENE flow ,PLIOCENE Epoch ,SPECIES diversity ,RIVER conservation - Abstract
The relative roles of rivers versus refugia in shaping the high levels of species diversity in tropical rainforests have been widely debated for decades. Only recently has it become possible to take an integrative approach to test predictions derived from these hypotheses using genomic sequencing and paleo‐species distribution modeling. Herein, we tested the predictions of the classic river, refuge, and river‐refuge hypotheses on diversification in the arboreal sub‐Saharan African snake genus Toxicodryas. We used dated phylogeographic inferences, population clustering analyses, demographic model selection, and paleo‐distribution modeling to conduct a phylogenomic and historical demographic analysis of this genus. Our results revealed significant population genetic structure within both Toxicodryas species, corresponding geographically to river barriers and divergence times from the mid‐Miocene to Pliocene. Our demographic analyses supported the interpretation that rivers are indications of strong barriers to gene flow among populations since their divergence. Additionally, we found no support for a major contraction of suitable habitat during the last glacial maximum, allowing us to reject both the refuge and river‐refuge hypotheses in favor of the river‐barrier hypothesis. Based on conservative interpretations of our species delimitation analyses with the Sanger and ddRAD data sets, two new cryptic species are identified from east‐central Africa. This study highlights the complexity of diversification dynamics in the African tropics and the advantages of integrative approaches to studying speciation in tropical regions. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
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3. Exploring rain forest diversification using demographic model testing in the African foam‐nest treefrog Chiromantis rufescens.
- Author
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Leaché, Adam D., Portik, Daniel M., Rivera, Danielle, Rödel, Mark‐Oliver, Penner, Johannes, Gvoždík, Václav, Greenbaum, Eli, Jongsma, Gregory F. M., Ofori‐Boateng, Caleb, Burger, Marius, Eniang, Edem A., Bell, Rayna C., and Fujita, Matthew K.
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RAIN forests ,DEMOGRAPHY ,MITOCHONDRIAL DNA ,SPECIES distribution ,GENE flow ,DEMOGRAPHIC change - Abstract
Aim: Species with wide distributions spanning the African Guinean and Congolian rain forests are often composed of genetically distinct populations or cryptic species with geographic distributions that mirror the locations of the remaining forest habitats. We used phylogeographic inference and demographic model testing to evaluate diversification models in a widespread rain forest species, the African foam‐nest treefrog Chiromantis rufescens. Location: Guinean and Congolian rain forests, West and Central Africa. Taxon: Chiromantis rufescens. Methods: We collected mitochondrial DNA (mtDNA) and single‐nucleotide polymorphism (SNP) data for 130 samples of C. rufescens. After estimating population structure and inferring species trees using coalescent methods, we tested demographic models to evaluate alternative population divergence histories that varied with respect to gene flow, population size change and periods of isolation and secondary contact. Species distribution models were used to identify the regions of climatic stability that could have served as forest refugia since the last interglacial. Results: Population structure within C. rufescens resembles the major biogeographic regions of the Guinean and Congolian forests. Coalescent‐based phylogenetic analyses provide strong support for an early divergence between the western Upper Guinean forest and the remaining populations. Demographic inferences support diversification models with gene flow and population size changes even in cases where contemporary populations are currently allopatric, which provides support for forest refugia and barrier models. Species distribution models suggest that forest refugia were available for each of the populations throughout the Pleistocene. Main conclusions: Considering historical demography is essential for understanding population diversification, especially in complex landscapes such as those found in the Guineo–Congolian forest. Population demographic inferences help connect the patterns of genetic variation to diversification model predictions. The diversification history of C. rufescens was shaped by a variety of processes, including vicariance from river barriers, forest fragmentation and adaptive evolution along environmental gradients. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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4. Evolutionary history of burrowing asps (Lamprophiidae: Atractaspidinae) with emphasis on fang evolution and prey selection.
- Author
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Portillo, Frank, Stanley, Edward L., Branch, William R., Conradie, Werner, Rödel, Mark-Oliver, Penner, Johannes, Barej, Michael F., Kusamba, Chifundera, Muninga, Wandege M., Aristote, Mwenebatu M., Bauer, Aaron M., Trape, Jean-François, Nagy, Zoltán T., Carlino, Piero, Pauwels, Olivier S. G., Menegon, Michele, Ineich, Ivan, Burger, Marius, Zassi-Boulou, Ange-Ghislain, and Mazuch, Tomáš
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BIOTIC communities ,BIOLOGICAL evolution ,LIFE sciences ,POPULATION biology ,LIFE (Biology) - Abstract
Atractaspidines are poorly studied, fossorial snakes that are found throughout Africa and western Asia, including the Middle East. We employed concatenated gene-tree analyses and divergence dating approaches to investigate evolutionary relationships and biogeographic patterns of atractaspidines with a multi-locus data set consisting of three mitochondrial (16S, cyt b, and ND4) and two nuclear genes (c-mos and RAG1). We sampled 91 individuals from both atractaspidine genera (Atractaspis and Homoroselaps). Additionally, we used ancestral-state reconstructions to investigate fang and diet evolution within Atractaspidinae and its sister lineage (Aparallactinae). Our results indicated that current classification of atractaspidines underestimates diversity within the group. Diversification occurred predominantly between the Miocene and Pliocene. Ancestral-state reconstructions suggest that snake dentition in these taxa might be highly plastic within relatively short periods of time to facilitate adaptations to dynamic foraging and life-history strategies. [ABSTRACT FROM AUTHOR]
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- 2019
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5. The bii4africa dataset of faunal and floral population intactness estimates across Africa's major land uses.
- Author
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Clements HS, Do Linh San E, Hempson G, Linden B, Maritz B, Monadjem A, Reynolds C, Siebert F, Stevens N, Biggs R, De Vos A, Blanchard R, Child M, Esler KJ, Hamann M, Loft T, Reyers B, Selomane O, Skowno AL, Tshoke T, Abdoulaye D, Aebischer T, Aguirre-Gutiérrez J, Alexander GJ, Ali AH, Allan DG, Amoako EE, Angedakin S, Aruna E, Avenant NL, Badjedjea G, Bakayoko A, Bamba-Kaya A, Bates MF, Bates PJJ, Belmain SR, Bennitt E, Bradley J, Brewster CA, Brown MB, Brown M, Bryja J, Butynski TM, Carvalho F, Channing A, Chapman CA, Cohen C, Cords M, Cramer JD, Cronk N, Cunneyworth PMK, Dalerum F, Danquah E, Davies-Mostert HT, de Blocq AD, De Jong YA, Demos TC, Denys C, Djagoun CAMS, Doherty-Bone TM, Drouilly M, du Toit JT, Ehlers Smith DA, Ehlers Smith YC, Eiseb SJ, Fashing PJ, Ferguson AW, Fernández-García JM, Finckh M, Fischer C, Gandiwa E, Gaubert P, Gaugris JY, Gibbs DJ, Gilchrist JS, Gil-Sánchez JM, Githitho AN, Goodman PS, Granjon L, Grobler JP, Gumbi BC, Gvozdik V, Harvey J, Hauptfleisch M, Hayder F, Hema EM, Herbst M, Houngbédji M, Huntley BJ, Hutterer R, Ivande ST, Jackson K, Jongsma GFM, Juste J, Kadjo B, Kaleme PK, Kamugisha E, Kaplin BA, Kato HN, Kiffner C, Kimuyu DM, Kityo RM, Kouamé NG, Kouete T M, le Roux A, Lee ATK, Lötter MC, Lykke AM, MacFadyen DN, Macharia GP, Madikiza ZJK, Mahlaba TAM, Mallon D, Mamba ML, Mande C, Marchant RA, Maritz RA, Markotter W, McIntyre T, Measey J, Mekonnen A, Meller P, Melville HI, Mganga KZ, Mills MGL, Minnie L, Missoup AD, Mohammad A, Moinde NN, Moise BFE, Monterroso P, Moore JF, Musila S, Nago SGA, Namoto MW, Niang F, Nicolas V, Nkenku JB, Nkrumah EE, Nono GL, Norbert MM, Nowak K, Obitte BC, Okoni-Williams AD, Onongo J, O'Riain MJ, Osinubi ST, Parker DM, Parrini F, Peel MJS, Penner J, Pietersen DW, Plumptre AJ, Ponsonby DW, Porembski S, Power RJ, Radloff FGT, Rambau RV, Ramesh T, Richards LR, Rödel MO, Rollinson DP, Rovero F, Saleh MA, Schmiedel U, Schoeman MC, Scholte P, Serfass TL, Shapiro JT, Shema S, Siebert SJ, Slingsby JA, Sliwa A, Smit-Robinson HA, Sogbohossou EA, Somers MJ, Spawls S, Streicher JP, Swanepoel L, Tanshi I, Taylor PJ, Taylor WA, Te Beest M, Telfer PT, Thompson DI, Tobi E, Tolley KA, Turner AA, Twine W, Van Cakenberghe V, Van de Perre F, van der Merwe H, van Niekerk CJG, van Wyk PCV, Venter JA, Verburgt L, Veron G, Vetter S, Vorontsova MS, Wagner TC, Webala PW, Weber N, Weier SM, White PA, Whitecross MA, Wigley BJ, Willems FJ, Winterbach CW, and Woodhouse GM
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- Animals, Biodiversity, Mammals, Vertebrates, Plants, Africa, Conservation of Natural Resources, Ecosystem
- Abstract
Sub-Saharan Africa is under-represented in global biodiversity datasets, particularly regarding the impact of land use on species' population abundances. Drawing on recent advances in expert elicitation to ensure data consistency, 200 experts were convened using a modified-Delphi process to estimate 'intactness scores': the remaining proportion of an 'intact' reference population of a species group in a particular land use, on a scale from 0 (no remaining individuals) to 1 (same abundance as the reference) and, in rare cases, to 2 (populations that thrive in human-modified landscapes). The resulting bii4africa dataset contains intactness scores representing terrestrial vertebrates (tetrapods: ±5,400 amphibians, reptiles, birds, mammals) and vascular plants (±45,000 forbs, graminoids, trees, shrubs) in sub-Saharan Africa across the region's major land uses (urban, cropland, rangeland, plantation, protected, etc.) and intensities (e.g., large-scale vs smallholder cropland). This dataset was co-produced as part of the Biodiversity Intactness Index for Africa Project. Additional uses include assessing ecosystem condition; rectifying geographic/taxonomic biases in global biodiversity indicators and maps; and informing the Red List of Ecosystems., (© 2024. The Author(s).)
- Published
- 2024
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6. Divergent trends in functional and phylogenetic structure in reptile communities across Africa.
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Ramm T, Cantalapiedra JL, Wagner P, Penner J, Rödel MO, and Müller J
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- Africa, Animals, Climate, Ecosystem, Quantitative Trait, Heritable, Species Specificity, Biodiversity, Phylogeny, Reptiles classification
- Abstract
Despite extensive research on ecological community compositions, general patterns across large-scale environmental gradients have remained unclear. A widely used explanatory model is the stress dominance hypothesis (SDH), predicting that the relative influence of environmental filtering is greater in stressful habitats while competition is more important in benign environments. Here, we test the SDH using African squamates as a model system to facilitate general predictions on community structures amidst changing global environments. For the first time we investigate changes in functional, phylogenetic and species diversity across continental, environmental gradients within a multidimensional, phylogenetically informed approach. Results suggest that phylogenetic patterns of African squamates were likely shaped by clade-specific biogeographic histories, whereas functional structure reflects SDH predictions. We further detected significant structuring at both local and regional spatial scales, emphasizing the impact of regional-historical processes on local assemblages, and the need for broad conceptual frameworks to detect general patterns of community composition.
- Published
- 2018
- Full Text
- View/download PDF
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