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1.
Mol Phylogenet Evol ; 158: 106988, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33059071

RESUMO

This paper reports a phylogeny of the African killifishes (Genus Nothobranchius, Order Cyprinodontiformes) informed by five genetic markers (three nuclear, two mitochondrial) of 80 taxa (seven undescribed and 73 of the 92 recognized species). These short-lived annual fishes occupy seasonally wet habitats in central and eastern Africa, and their distribution coincides largely with the East African Rift System (EARS). The fossil dates of sister clades used to constrain a chronometric tree of all sampled Nothobranchius recovered the origin of the genus at ~13.27 Mya. It was followed by the radiations of six principal clades through the Neogene. An ancestral area estimation tested competing biogeographical hypotheses to constrain the ancestral origin of the genus to the Nilo-Sudan Ecoregion, which seeded a mid-Miocene dispersal event into the Coastal ecoregion, followed closely (~10 Mya) by dispersals southward across the Mozambique coastal plain into the Limpopo Ecoregion. Extending westwards across the Tanzanian plateau, a pulse of radiations through the Pliocene were associated with dispersals and fragmentation of wetlands across the Kalahari and Uganda Ecoregions. We interpret this congruence of drainage rearrangements with dispersals and cladogenic events of Nothobranchius to reflect congruent responses to recurrent uplift and rifting. The coevolution of these freshwater fishes and wetlands is attributed to ultimate control by tectonics, as the EARS extended southwards during the Neogene. Geobiological consilience of the combined evidence supports a tectonic hypothesis for the evolution of Nothobranchius.


Assuntos
Genoma , Peixes Listrados/classificação , África , Animais , Núcleo Celular/genética , DNA/química , DNA/isolamento & purificação , DNA/metabolismo , Complexo IV da Cadeia de Transporte de Elétrons/classificação , Complexo IV da Cadeia de Transporte de Elétrons/genética , Glicosiltransferases/classificação , Glicosiltransferases/genética , Peixes Listrados/genética , Mitocôndrias/genética , Filogenia , Filogeografia , Análise de Sequência de DNA
2.
Nature ; 547(7662): 162, 2017 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-28703184
3.
J Hered ; 107(2): 101-3, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26695079

RESUMO

South-central Africa is characterized by an archipelago of wetlands, which has evolved in time and space since at least the Miocene, providing refugia for animal species during Pleistocene arid episodes. Their importance for biodiversity in the region is reflected in the evolution of a variety of specialist mammal and bird species, adapted to exploit these wetland habitats. Populations of lions (Panthera leo) across south-central and east Africa have contrasting signatures of mitochondrial DNA haplotypes and biparental nuclear DNA in wetland and savannah habitats, respectively, pointing to the evolution of distinct habitat preferences. This explains the absence of genetic admixture of populations from the Kalahari savannah of southwest Botswana and the Okavango wetland of northern Botswana, despite separation by only 500 km. We postulate that ancestral lions were wetland specialists and that the savannah lions evolved from populations that were isolated during arid Pleistocene episodes. Expansion of grasslands and the resultant increase in herbivore populations during mesic Pleistocene climatic episodes provided the stimulus for the rapid population expansion and diversification of the highly successful savannah lion specialists. Our model has important implications for lion conservation.


Assuntos
Variação Genética , Genética Populacional , Pradaria , Leões/genética , Áreas Alagadas , Animais , Botsuana , Conservação dos Recursos Naturais , DNA Mitocondrial/genética , Evolução Molecular , Haplótipos
4.
Zootaxa ; 5174(5): 508-524, 2022 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-36095385

RESUMO

A new seasonal killifish of the genus Nothobranchius is described from the Montepuez River system in northern Mozambique. The new species, Nothobranchius balamaensis Bragana Chakona, is differentiated from congeners by its characteristic colour pattern and molecular data further support its taxonomic distinctiveness. Phylogenetic results based on two mitochondrial and three nuclear genes confirms N. balamaensis is closely related to N. kirki and N. wattersi; all three belonging to the Coastal-Inland Clade. The new species is most similar in colour pattern to N. kirki sharing the characteristic of a deep red-orange colouration in the basal, proximal, and medial zones of the caudal and anal fins that grades to orange in the distal zone. This is a key feature that distinguishes these two species from all other Nothobranchius. The main distinguishing features between the new species and N. kirki is the presence of a light blue to white band or series of irregular markings in the proximal zone of the anal fin in N. kirki, versus the absence of such a colour pattern element in N. balamaensis, as well as differences in the dorsal fin pattern. When compared to all population groups of N. wattersi, the colour pattern of N. balamaensis is distinctive. Nothobranchius balamaensis is a relatively slender member of the genus, a characteristic that clearly distinguishes it from both N. kirki and N. wattersi. Nothobranchius balamaensis is currently only known from a few specimens from the type locality.


Assuntos
Ciprinodontiformes , Fundulidae , Animais , Moçambique , Filogenia , Rios
6.
Biol Rev Camb Philos Soc ; 93(1): 115-130, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28429851

RESUMO

We review the state of African ungulate taxonomy over the last 120 years, with an emphasis on the introduction of the polytypic species concept and the discipline's general neglect since the middle of the 20th century. We single out negative consequences of 'orthodox' taxonomy, highlighting numerous cases of neglect of threatened lineages, unsound translocations that led to lineage introgression, and cases of maladaptation to local conditions including parasitic infections. Additionally, several captive breeding programmes have been hampered by chromosome rearrangements caused by involuntary lineage mixing. We advocate that specimen-based taxonomy should regain its keystone role in mammal research and conservation biology, with its scientific values augmented with genomic evidence. While integration with molecular biology, ecology and behaviour is needed for a full understanding of ungulate alpha diversity, we stress that morphological diversity has been neglected despite its tremendous practical importance for some groups of 'utilizers' such as trophy hunters, wildlife tourists and conservationists. We conclude that there is no evidence that purported 'taxonomic inflation' has adverse effects on ungulate conservation: rather, it is taxonomic inertia that has such adverse effects. We stress that sound science, founded on robust taxonomy, should underpin effective sustainable management (hunting, ranching, captive breeding and reintroduction programmes) of this unique African natural resource.


Assuntos
Artiodáctilos/classificação , Artiodáctilos/fisiologia , Biodiversidade , Conservação dos Recursos Naturais , África , Animais
7.
PLoS One ; 10(9): e0137847, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26422465

RESUMO

In the context of molecularly-dated phylogenies, inferences informed by ancestral habitat reconstruction can yield valuable insights into the origins of biomes, palaeoenvironments and landforms. In this paper, we use dated phylogenies of 12 plant clades from the Cape Floristic Region (CFR) in southern Africa to test hypotheses of Neogene climatic and geomorphic evolution. Our combined dataset for the CFR strengthens and refines previous palaeoenvironmental reconstructions based on a sparse, mostly offshore fossil record. Our reconstructions show remarkable consistency across all 12 clades with regard to both the types of environments identified as ancestral, and the timing of shifts to alternative conditions. They reveal that Early Miocene land surfaces of the CFR were wetter than at present and were dominated by quartzitic substrata. These conditions continue to characterize the higher-elevation settings of the Cape Fold Belt, where they have fostered the persistence of ancient fynbos lineages. The Middle Miocene (13-17 Ma) saw the development of perennial to weakly-seasonal arid conditions, with the strongly seasonal rainfall regime of the west coast arising ~6.5-8 Ma. Although the Late Miocene may have seen some exposure of the underlying shale substrata, the present-day substrate diversity of the CFR lowlands was shaped by Pliocene-Pleistocene events. Particularly important was renewed erosion, following the post-African II uplift episode, and the reworking of sediments on the coastal platform as a consequence of marine transgressions and tectonic uplift. These changes facilitated adaptive radiations in some, but not all, lineages studied.


Assuntos
Evolução Biológica , Clima , Ecossistema , Fósseis , Filogenia , Plantas/classificação , África Austral , Biodiversidade , Flores/classificação , Fósseis/história , História Antiga , Fenômenos Fisiológicos Vegetais , Chuva , Estações do Ano
8.
PLoS One ; 10(4): e0125043, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25928886

RESUMO

A long history of research focused on the East Africa cichlid radiations (EAR) revealed discrepancies between mtDNA and nuclear phylogenies, suggesting that interspecific hybridisation may have been significant during the radiation of these fishes. The approximately 250 cichlid species of Lake Tanganyika have their roots in a monophyletic African cichlid assemblage, but controversies remain about the precise phylogenetic origin and placement of different lineages and consequently about L. Tanganyika colonization scenarios. 3312 AFLP loci and the mitochondrial ND2 gene were genotyped for 91 species representing almost all major lacustrine and riverine haplotilapiine east African cichlid lineages with a focus on L. Tanganyika endemics. Explicitly testing for the possibility of ancient hybridisation events, a comprehensive phylogenetic network hypothesis is proposed for the origin and diversification of L. Tanganyika cichlids. Inference of discordant phylogenetic signal strongly suggests that the genomes of two endemic L. Tanganyika tribes, Eretmodini and Tropheini, are composed of an ancient mixture of riverine and lacustrine lineages. For the first time a strong monophyly signal of all non-haplochromine mouthbrooding species endemic to L. Tanganyika ("ancient mouthbrooders") was detected. Further, in the genomes of early diverging L. Tanganyika endemics Trematocarini, Bathybatini, Hemibatini and Boulengerochromis genetic components of other lineages belonging to the East African Radiation appear to be present. In combination with recent palaeo-geological results showing that tectonic activity in the L. Tanganyika region resulted in highly dynamic and heterogeneous landscape evolution over the Neogene and Pleistocene, the novel phylogenetic data render a single lacustrine basin as the geographical cradle of the endemic L. Tanganyika cichlid lineages unlikely. Instead a scenario of a pre-rift origin of several independent L. Tanganyika precursor lineages which diversified in ancient rivers and precursor lakes and then amalgamated in the extant L. Tanganyika basin is put forward as an alternative: the 'melting pot Tanganyika' hypothesis.


Assuntos
Ciclídeos/genética , Animais , Ciclídeos/classificação , DNA Mitocondrial/genética , Genótipo , Lagos , Filogenia
9.
Diversity (Basel) ; 5(2): 374-392, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24072980

RESUMO

Although constituting more than 100,000 described species, protists are virtually ignored within the arena of biodiversity conservation. One reason is the widespread belief that the majority of protists have cosmopolitan distributions, in contrast to the highly hetereogenous biogeography of the "mega-Metazoa". However, modern research reveals that about one third of the known protists have restricted distributions, which endorses their conservation, at least in special cases. Here, we report what probably ranks as the first successful conservation intervention focused directly on known protist diversity. It is justified by unique species, type localities, and landscape maintenance as evidence for legislation. The protected habitat comprises an ephemeral pond, which is now a "Natural Monument" for ciliated protozoa. This wetland occupies a natural depression on the Krauthügel ("cabbage hill") south of the fortress of Salzburg City. When filled, the claviform pond has a size of ~30 × 15 m and a depth rarely surpassing 30 cm. Water is present only for some days or weeks, depending on heavy and/or prolonged rain. The pond occupied an agricultural field where root and leafy vegetables were cultivated for possibly more than 200 years. In the 1960s, this area became a grassland utilized as an autumn pasture, but was abandoned in the 1990s. Repeated sampling between 1982 and 2012 recovered a total of at least 150 ciliate taxa, of which 121 were identified to species level. Eight species were new to science, and an additional 10 poorly known species were reinvestigated and neotypified with populations from the Krauthügel pond. Both endemism and type localities justify the argument that the "integrative approach" in biodiversity and conservation issues should include protists and micro-metazoans. We argue that Krauthügel holds a unique reference node for biodiversity inventories to obtain the baseline knowledge-which is the prerequisite to monitor ecosystem integrity-and detect and evaluate impacts of natural and anthropogenic disturbances.

10.
PLoS One ; 7(9): e41744, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22984399

RESUMO

Gigantism and dwarfism evolve in vertebrates restricted to islands. We describe four new species in the Rhinolophus hildebrandtii species-complex of horseshoe bats, whose evolution has entailed adaptive shifts in body size. We postulate that vicissitudes of palaeoenvironments resulted in gigantism and dwarfism in habitat islands fragmented across eastern and southern Africa. Mitochondrial and nuclear DNA sequences recovered two clades of R. hildebrandtii senso lato which are paraphyletic with respect to a third lineage (R. eloquens). Lineages differ by 7.7 to 9.0% in cytochrome b sequences. Clade 1 includes R. hildebrandtii sensu stricto from the east African highlands and three additional vicariants that speciated across an Afromontane archipelago through the Plio-Pleistocene, extending from the Kenyan Highlands through the Eastern Arc, northern Mozambique and the Zambezi Escarpment to the eastern Great Escarpment of South Africa. Clade 2 comprises one species confined to lowland savanna habitats (Mozambique and Zimbabwe). A third clade comprises R. eloquens from East Africa. Speciation within Clade 1 is associated with fixed differences in echolocation call frequency, and cranial shape and size in populations isolated since the late Pliocene (ca 3.74 Mya). Relative to the intermediate-sized savanna population (Clade 2), these island-populations within Clade 1 are characterised by either gigantism (South African eastern Great Escarpment and Mts Mabu and Inago in Mozambique) or dwarfism (Lutope-Ngolangola Gorge, Zimbabwe and Soutpansberg Mountains, South Africa). Sympatry between divergent clades (Clade 1 and Clade 2) at Lutope-Ngolangola Gorge (NW Zimbabwe) is attributed to recent range expansions. We propose an "Allometric Speciation Hypothesis", which attributes the evolution of this species complex of bats to divergence in constant frequency (CF) sonar calls. The origin of species-specific peak frequencies (overall range = 32 to 46 kHz) represents the allometric effect of adaptive divergence in skull size, represented in the evolution of gigantism and dwarfism in habitat islands.


Assuntos
Evolução Biológica , Tamanho Corporal , Quirópteros/anatomia & histologia , Quirópteros/genética , Variação Genética , Ilhas , Acústica , África , Animais , Tamanho Corporal/genética , Quirópteros/classificação , Citocromos b/genética , Bases de Dados Genéticas , Nanismo/genética , Nanismo/veterinária , Ecolocação , Feminino , Genótipo , Geografia , Gigantismo/genética , Gigantismo/veterinária , Masculino , Dados de Sequência Molecular , Filogenia , Análise de Componente Principal , Fatores de Tempo
11.
PLoS One ; 6(12): e28775, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22194910

RESUMO

The geobiotic history of landscapes can exhibit controls by tectonics over biotic evolution. This causal relationship positions ecologically specialized species as biotic indicators to decipher details of landscape evolution. Phylogeographic statistics that reconstruct spatio-temporal details of evolutionary histories of aquatic species, including fishes, can reveal key events of drainage evolution, notably where geochronological resolution is insufficient. Where geochronological resolution is insufficient, phylogeographic statistics that reconstruct spatio-temporal details of evolutionary histories of aquatic species, notably fishes, can reveal key events of drainage evolution. This study evaluates paleo-environmental causes of mitochondrial DNA (mtDNA) based phylogeographic records of tigerfishes, genus Hydrocynus, in order to reconstruct their evolutionary history in relation to landscape evolution across Africa. Strong geographical structuring in a cytochrome b (cyt-b) gene phylogeny confirms the established morphological diversity of Hydrocynus and reveals the existence of five previously unknown lineages, with Hydrocynus tanzaniae sister to a clade comprising three previously unknown lineages (Groups B, C and D) and H. vittatus. The dated phylogeny constrains the principal cladogenic events that have structured Hydrocynus diversity from the late Miocene to the Plio-Pleistocene (ca. 0-16 Ma). Phylogeographic tests reveal that the diversity and distribution of Hydrocynus reflects a complex history of vicariance and dispersals, whereby range expansions in particular species testify to changes to drainage basins. Principal divergence events in Hydrocynus have interfaced closely with evolving drainage systems across tropical Africa. Tigerfish evolution is attributed to dominant control by pulses of geotectonism across the African plate. Phylogenetic relationships and divergence estimates among the ten mtDNA lineages illustrates where and when local tectonic events modified Africa's Neogene drainage. Haplotypes shared amongst extant Hydrocynus populations across northern Africa testify to recent dispersals that were facilitated by late Neogene connections across the Nilo-Sahelian drainage. These events in tigerfish evolution concur broadly with available geological evidence and reveal prominent control by the African Rift System, evident in the formative events archived in phylogeographic records of tigerfish.


Assuntos
Peixes/genética , Variação Genética , Geografia , Fenômenos Geológicos , Paleontologia , Filogenia , África , Animais , Teorema de Bayes , Citocromos b/genética , DNA Mitocondrial/genética , Ecossistema , Haplótipos/genética , Lagos , Modelos Biológicos , Dados de Sequência Molecular , Dinâmica Populacional , Rios , Especificidade da Espécie , Fatores de Tempo
12.
Biodivers Conserv ; 19(1): 291-303, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21472034

RESUMO

Embracing comparative biology, natural history encompasses those sciences that discover, decipher and classify unique (idiographic) details of landscapes, and extinct and extant biodiversity. Intrinsic to these multifarious roles in expanding and consolidating research and knowledge, natural history endows keystone support to the veracity of law-like (nomothetic) generalizations in science. What science knows about the natural world is governed by an inherent function of idiographic discovery; characteristic of natural history, this relationship is exemplified wherever an idiographic discovery overturns established wisdom. This nature of natural history explicates why inventories are of such epistemological importance. Unfortunately, a Denigration of Natural History weakens contemporary science from within. It expresses in the prevalent, pervasive failure to appreciate this pivotal role of idiographic research: a widespread disrespect for how natural history undergirds scientific knowledge. Symptoms of this Denigration of Natural History present in negative impacts on scientific research and knowledge. One symptom is the failure to appreciate and support the inventory and monitoring of biodiversity. Another resides in failures of scientiometrics to quantify how taxonomic publications sustain and improve knowledge. Their relevance in contemporary science characteristically persists and grows; so the temporal eminence of these idiographic publications extends over decades. This is because they propagate a succession of derived scientific statements, findings and/or conclusions - inherently shorter-lived, nomothetic publications. Widespread neglect of natural science collections is equally pernicious, allied with disregard for epistemological functions of specimens, whose preservation maintains the veracity of knowledge. Last, but not least, the decline in taxonomic expertise weakens research capacity; there are insufficient skills to study organismal diversity in all of its intricacies. Beyond weakening research capacities and outputs across comparative biology, this Denigration of Natural History impacts on the integrity of knowledge itself, undermining progress and pedagogy throughout science. Unprecedented advances in knowledge are set to follow on consummate inventories of biodiversity, including the protists. These opportunities challenge us to survey biodiversity representatively-detailing the natural history of species. Research strategies cannot continue to ignore arguments for such an unprecedented investment in idiographic natural history. Idiographic shortcuts to general (nomothetic) insights simply do not exist. The biodiversity sciences face a stark choice. No matter how charismatic its portrayed species, an incomplete 'Brochure of Life' cannot match the scientific integrity of the 'Encyclopedia of Life'.

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