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1.
FRANÇOIS MUNOZ THIERRY PAILLER INGRID KOTTKE CÉDRIC GONNEAU MARC‐ANDRÉ SELOSSE 《Molecular ecology》2012,21(20):5098-5109
Characterizing the architecture of bipartite networks is increasingly used as a framework to study biotic interactions within their ecological context and to assess the extent to which evolutionary constraint shape them. Orchid mycorrhizal symbioses are particularly interesting as they are viewed as more beneficial for plants than for fungi, a situation expected to result in an asymmetry of biological constraint. This study addressed the architecture and phylogenetic constraint in these associations in tropical context. We identified a bipartite network including 73 orchid species and 95 taxonomic units of mycorrhizal fungi across the natural habitats of Reunion Island. Unlike some recent evidence for nestedness in mycorrhizal symbioses, we found a highly modular architecture that largely reflected an ecological barrier between epiphytic and terrestrial subnetworks. By testing for phylogenetic signal, the overall signal was stronger for both partners in the epiphytic subnetwork. Moreover, in the subnetwork of epiphytic angraecoid orchids, the signal in orchid phylogeny was stronger than the signal in fungal phylogeny. Epiphytic associations are therefore more conservative and may co‐evolve more than terrestrial ones. We suggest that such tighter phylogenetic specialization may have been driven by stressful life conditions in the epiphytic niches. In addition to paralleling recent insights into mycorrhizal networks, this study furthermore provides support for epiphytism as a major factor affecting ecological assemblage and evolutionary constraint in tropical mycorrhizal symbioses. 相似文献
2.
Jerome Goddard 《Journal of vector ecology》2009,34(2):238-242
Rickettsia parkeri, a member of the spotted fever group rickettsias, was first described in 1939 and was thought to be non‐pathogenic until recently, when it was found to cause a spotted fever‐like illness in humans and areas of necrosis (eschars) at the sites of tick bites. Accordingly, there is currently much interest in this emerging pathogen. In this study, all published articles concerning R. parkeri were reviewed and analyzed for evidence of relatedness among this agent and other spotted fever group (SFG) rickettsiae which also produce similar clinical syndromes and/or eschars, including R. conorii, R. africae, and R. sibirica. A synthesis of the historical (antigenic) and recent (molecular) data supporting a phylogenetic sub‐grouping of these SFG organisms is presented and comments are offered about the taxonomy of rickettsial organisms in general, and R. parkeri in particular. 相似文献
3.
Aim To describe a protocol for incorporating a temporal dimension into historical biogeographical analysis, while maintaining the essential independence of all datasets, involving the generation of general area cladograms. Location Global. Methods General area cladograms (GACs) are a reconstruction of the evolutionary history of a set of areas and unrelated clades within those areas. Nodes on a GAC correspond to speciation events in a group of taxa; general nodes are those at which multiple unrelated clades speciate. We undertake temporal calibration of GACs using molecular clock estimates of splitting events between extant taxa as well as first appearance data from the fossil record. We present two examples based on re‐analysis of previously published data: first, a temporally calibrated GAC generated from secondary Brooks parsimony analysis (BPA) of six extant bird clades from the south‐west of North America using molecular clock estimates of divergence times; and second, an analysis of African Neogene mammals based on a phylogenetic analysis for comparing trees (PACT) analysis. Results A hypothetical example demonstrates how temporal calibration reveals potentially critical information about the timing of both unique and general events, while also illustrating instances of incongruence between dates generated from molecular clock estimates and fossils. For the African Neogene mammal dataset, our analysis reveals that most mammal clades underwent geodispersal associated with the Neogene climatic optimum (c. 16 Ma) and vicariant speciation in central Africa correlated with increased aridity and cooler temperatures around 2.5 Ma. Main conclusions Temporally calibrated GACs are valuable tools for assessing whether coordinated patterns of speciation are associated with large‐scale climatic or tectonic phenomena. 相似文献
4.
Despite similar ecology, mating systems and female preferences for supernormal tails, the 17 species of African widowbirds and bishops (Euplectes spp.) show astonishing variation in male tail ornamentation. Whereas bishops retain their brown nonbreeding tails in nuptial plumage, widowbirds grow black nuptial tails, varying in length from a few centimetres in E. axillaris to the extreme half metre train of E. progne. Here, we phylogenetically reconstruct the evolution of the discrete trait, nuptial tail and the continuous trait, tail length, using a molecular phylogeny of 33 Euplectes subspecies. Unlike many recent findings of labile evolution of plumage ornaments, our results suggest that the nuptial tail of Euplectes is a derived and phylogenetically conserved ornamental trait that, once gained, shows directional evolution in its expression. Directionality is demonstrated in the trivial sense of a short‐tailed ancestor, and by contingency and randomization tests suggesting that branches with increasing tail length are overrepresented. This supports an early origin and strong retention of directional female mate choice in widowbirds and bishops, as previously indicated by empirical and experimental results, and provides a less labile, yet rapid scenario of sexually selected diversification. 相似文献
5.
Richard O. Prum 《Evolution; international journal of organic evolution》1994,48(5):1657-1675
Phylogenetic analyses of lekking, lek spatial organization, and cooperative and coordinated lek display in the manakins (Aves: Pipridae) demonstrate that variation in social behavior in the group has a strong, phylogenetic component. Two of the three classes of social behavior examined also show significant phylogenetic constraints. Current adaptive plasticity models are insufficient to explain the phylogenetic variation in these behaviors in the manakins. These findings support the conclusion that vertebrate reproductive social behavior has an evolutionary history, and that it is not determined solely by adaptive individual plasticity to current conditions. The evolution of social behavior, particularly through sexual selection, can have historical consequences that can limit subsequent behavioral adaptation. 相似文献
6.
Loïc Pellissier Charlotte Ndiribe Anne Dubuis Jean‐Nicolas Pradervand Nicolas Salamin Antoine Guisan Sergio Rasmann 《Ecology letters》2013,16(5):600-608
Understanding drivers of biodiversity patterns is of prime importance in this era of severe environmental crisis. More diverse plant communities have been postulated to represent a larger functional trait‐space, more likely to sustain a diverse assembly of herbivore species. Here, we expand this hypothesis to integrate environmental, functional and phylogenetic variation of plant communities as factors explaining the diversity of lepidopteran assemblages along elevation gradients in the Swiss Western Alps. According to expectations, we found that the association between butterflies and their host plants is highly phylogenetically structured. Multiple regression analyses showed the combined effect of climate, functional traits and phylogenetic diversity in structuring butterfly communities. Furthermore, we provide the first evidence that plant phylogenetic beta diversity is the major driver explaining butterfly phylogenetic beta diversity. Along ecological gradients, the bottom up control of herbivore diversity is thus driven by phylogenetically structured turnover of plant traits as well as environmental variables. 相似文献
7.
H. Ben Slimen F. Suchentrunk A. Memmi H. Sert U. Kryger P.C. Alves A. Ben Ammar Elgaaied 《Journal of Zoological Systematics and Evolutionary Research》2006,44(1):88-99
Systematics and taxonomy of hares of the genus Lepus (Lagomorpha) are under contentious debate, and phylogenetic relationships among many taxa are not well understood. Here we study genetic differentiation and evolutionary relationships among North African hares, currently considered subspecies of Lepus capensis , cape hares ( L. capensis ) from the Cape province in South Africa, and brown hares ( L. europeaus ) from Europe and Anatolia, using maternally (mtDNA) and biparentally (allozymes) inherited markers. A polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of a c. 1.8 kb long segment of the mitochondrial control region using eight hexanucleotide-recognizing restriction endonucleases yielded 28 haplotypes, and horizontal starch gel electrophoresis of proteins encoded by 25 structural gene loci revealed 52 alleles at 18 polymorphic loci. Diverse phylogenetic analyses (neighbor joining dendrogram, median joining network, multidimensional scaling of pairwise distances, AMOVA, F -statistics, hierarchical F -statistics) of genetic variants revealed marked substructuring of mtDNA into three phylogeographic groups, namely an African, a central European, and an Anatolian, but a somewhat less pronounced overall differentiation of the nuclear genome, despite a relatively high number of population-specific (private) alleles. However, all our results are not incongruent with Petter's (1959: Mammalia 23 , 41; 1961: Z. f. Säugetierkunde 26 , 30; 1972 : Société Des Sciences Naturelles et Physiques du Maroc 52 , 122) hypothesis that North African hares generally belong to L. capensis and that brown hares should be included in this species as well. 相似文献
8.
SCOTT LYELL GARDNER 《Zoological Journal of the Linnean Society》1991,102(2):169-201
Coevolution was studied in six species of rodents of the genus Ctenomys and their parasitic nematodes of the genus Paraspidodera , collected in Bolivia. Representatives of the families Octodontidae and Caviidae were used as outgroups for the mammals, and nematodes from caviids were used as outgroups of the nematodes from ctenomyids. For the nematodes, quantitative and qualitative morphological characteristics of both males and females and electrophoretic characters of both sexes were used to generate phylogenetic hypotheses of evolutionary relationships of the OTUs occurring in hosts of different species. Concordance estimates of cladograms generated from biochemical—genetic and morphological data of the nematodes show a percentage incongruence (Mickevich-Farris Incongruence Statistic or I MF ) of 8.23% in the character sets. Parsimony mapping, testing concordance of topologies between the trees derived from both analysis of both morphological and biochemical—genetic data indicates an overall agreement of 82.3°. Comparisons of topologies of the host and parasite cladograms, as measured with parsimony mapping, showed 70.8% concordance, indicating substantially more cospeciation than host-switching in the Ctenomys-Paraspidodera host-parasite system. Nematodes of the genus Paraspidodera appear to have invaded the Ctenomys lineage from an origin in caviids sometime before the ctenomyids began to diversify in early Pleistocene time. 相似文献
9.
A. Ma Fernández-Peralta J. J. González-Aguilera 《Plant Systematics and Evolution》1986,152(3-4):167-183
Six closely related taxa of the sect.Eusideritis of the genusSideritis (S. leucantha, S. pusilla, S. flavovirens, S. granatensis, S. biflora andS. osteoxylla) are analysed to elucidate their phylogenetic relationships and position within the sect.Eusideritis. Meiotic behaviour, karyotype features, size and fertility of pollen grains, DNA amounts and seed protein profiles are reviewed. A polyploid origin of the group (from x = 7) and the further diversification through dysploidy and chromosome repatterning is postulated.S. osteoxylla is apparently of hybrid origin. 相似文献
10.
Gerlinde Linne von Berg Alexander Samoylov Manfred Klaas Peter Hanelt 《Plant Systematics and Evolution》1996,200(3-4):253-261
The utility of chloroplast DNA variation for checking a recently proposed infrageneric classification of the genusAllium was tested. cpDNA restriction patterns of 49 species representing the main subgenera, sections, and subsections of the existing classification were compared. 363 different fragments generated by 4 restriction enzymes were identified and analysed by UPGMA clustering. The resulting phenogram largely confirms the subgeneric classification based on an integration of morphological and other methods. 相似文献