| 1. |
- Dehghani, Reihaneh, et al.
(författare)
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Phylogeography of the White-tailed Mongoose (Herpestidae, Carnivora, Mammalia) - a phylogenetic study based on partial mtDNA of the control region (D-loop)
- 2008
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Ingår i: Journal of Zoology. - : Wiley. - 0952-8369 .- 1469-7998. ; :276, s. 385-393
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Tidskriftsartikel (refereegranskat)abstract
- The phylogeography of the white-tailed mongoose Ichneumia albicauda is examinedusing phylogenetic analyses based on partial sequences of the mitochondrialcontrol region. The phylogeny is used to: (1) Analyse the phylogeographic patternof I. albicauda; (2) discuss the existing delimitation of subspecies; (3) test if thecoloration of the tail tip, generally white but occasionally black in West Africanspecimens, is a species polymorphism or if it has phylogenetic significance. Ourresults suggest a north–south division within white-tailed mongoose populations,and within the northern clade, we observe an east–west subdivision. Thisphylogenetic pattern is partly in concordance with the traditional division into sixsubspecies. The white-tailed mongoose probably originated in southern Africa,from where it dispersed northwards and colonized eastern and western parts ofAfrica, as well as the Arabian Peninsula. Colour polymorphism observed inWestern populations reflects variation at the individual level.
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| 2. |
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| 3. |
- Ronse De Craene, Louis, et al.
(författare)
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Flower morphology and anatomy of Sabia (Sabiaceae): structural basis of an advanced pollination system among basal eudicots
- 2015
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Ingår i: Plant Systematics and Evolution. - : Springer Science and Business Media LLC. - 0378-2697 .- 1615-6110 .- 2199-6881. ; 301:6, s. 1543-1553
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Tidskriftsartikel (refereegranskat)abstract
- Flowers of four species of Sabia are investigated using scanning electron and light microscopy to understand the complex floral system of Sabiaceae and to contribute to the understanding of the systematic position of the family among early diverging eudicots. The structure of the mature flower and the floral anatomy are here described and compared with that of the sister genus Meliosma. The floral structure is relatively uniform with the greatest variability in the shape of the nectary and the differentiation of the style. Flowers share a similar pollen release mechanism, as pollen is extruded from the monosporangiate thecae through an inward-out dehiscence process leading to seemingly extrorse anthers occasionally accompanied by the curving of the upper part of the filaments. The bicarpellate ovary is divided in a synascidiate zone and a symplicate zone of similar size with two superposed unitegmic ovules per carpel. The floral Bauplan of Sabia can be interpreted as precursory to a further evolution of the monosymmetric flower of Meliosma, as both genera share numerous characters. The isolated position of Sabiaceae in the early diverging eudicots is highlighted by their unique floral morphology, although several features point to a link with Ranunculales, such as Menispermaceae. These probably reflect the existence of apomorphic tendencies shared by members of the early diverging eudicots.
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| 4. |
- Sanmartin, Isabel, et al.
(författare)
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West Wind Drift revisited : testing for directional dispersal in the Southern Hemisphere using event-based tree fitting
- 2007
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Ingår i: Journal of Biogeography. - : Wiley. - 0305-0270 .- 1365-2699. ; 34:3, s. 398-416
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Tidskriftsartikel (refereegranskat)abstract
- Aim Recent studies suggest that if constrained by prevailing wind or ocean currents dispersal may produce predictable, repeated distribution patterns. Dispersal mediated by the West Wind Drift (WWD) and Antarctic Circumpolar Current (AAC) has often been invoked to explain the floristic similarities of Australia, South America and New Zealand. If these systems have been important dispersal vectors then eastward dispersal - from Australia to New Zealand and the western Pacific to South America - is expected to predominate. We investigate whether phylogenies for Southern Hemisphere plant groups provide evidence of historical dispersal asymmetry and more specifically whether inferred asymmetries are consistent with the direction of the WWD/AAC. Location Southern Hemisphere. Methods We assembled a data set of 23 published phylogenies for plant groups that occur in New Zealand, Australia and/or South America. We used parsimony-based tree fitting to infer the number and direction of dispersals within each group. Observed dispersal asymmetries were tested for significance against a distribution of expected values. Results Our analyses suggest that dispersal has played a major role in establishing present distributions and that there are significant patterns of asymmetry in Southern Hemisphere dispersal. Consistent with the eastward direction of the WWD/ACC, dispersal from Australia to New Zealand was inferred significantly more often than in the reverse direction. No significant patterns of dispersal asymmetry were found between the western Pacific landmasses and South America. However, eastward dispersal was more frequently inferred between Australia and South America, while for New Zealand-South American events westward dispersal was more common. Main Conclusions Our results suggest that eastward circumpolar currents have constrained the dispersal of plants between Australia and New Zealand. However, the WWD/ACC appear to have had less of an influence on dispersal between the western Pacific landmasses and South America. This observation may suggest that differences in dispersal mechanism are important - direct wind or water dispersal vs. stepping-stone dispersal along the Antarctic coast. While our analyses provide useful preliminary insights into dispersal asymmetry in the Southern Hemisphere we will need larger data sets and additional methodological advances in order to test fully these dispersal patterns and infer processes from phylogenetic data.
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| 5. |
- Wanntorp, Livia, et al.
(författare)
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Past diversity of Proteaceae on subantarctic Campbell Island, a remote outpost of Gondwana
- 2011
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Ingår i: Cretaceous Research. - : Elsevier BV. - 0195-6671. ; 32:3, s. 357-367
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Tidskriftsartikel (refereegranskat)abstract
- Twelve fossil species of Proteaceous pollen, predominantly attributable to Proteacidites and Beaupreaidites, were recovered from the Maastrichtian-Paleocene sedimentary succession of the Garden Cove Formation on Campbell Island, the southernmost landmass of the Zealandia continent. Among these are two new species, Proteacidites campbellensis and Proteacidites hortisinus. The high diversity of Proteaceae pollen in the sediments encompassing the Cretaceous-Paleogene boundary on Campbell Island is consistent with the fossil record from neighbouring landmasses but strongly contrasts with the impoverished record of the family in the extant New Zealand flora. Examples of Beauprea- and Knightia-like pollen in the Campbell Island assemblages confirm the presence of these lineages on Zealandia by the end of the Cretaceous and suggest that their present endemism in New Caledonia and New Zealand can be explained in terms of relictual vicariant distributions, perhaps modified by northward tracking of warmer climates on Zealandia through the Cenozoic. (C) 2011 Elsevier Ltd. All rights reserved.
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| 6. |
- Wanntorp, Livia, et al.
(författare)
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Phylogenetic relationships between Hoya and the monotypic genera Madangia, Absolmsia, and Micholitzia (Apocynaceae, Marsdenieae) : Insights from flower morphology
- 2007
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Ingår i: Annals of the Missouri Botanical Garden. - 0026-6493 .- 2162-4372. ; 94:1, s. 36-55
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Tidskriftsartikel (refereegranskat)abstract
- The monotypic genera Absolmsia Kuntze, Madangia P. I. Forst., Liddle & I. M. Liddle, and Micholitzia N. E. Br. (Apocynaceae, Marsdenieae) are, according to molecular phylogenetic results, nested within the genus Hoya R. Br. Together with Dischidia R. Br., these genera are considered to comprise a well-supported Glade within the tribe Marsdenieae. Flower morphology of Absolmsia, Madangia, and Micholitzia is examined by SEM and light microscopy and compared to that of the related H. caudata Hook. f., H. curtisii King & Gamble, H. hypolasia Schltr., H. lacunosa Blume. H. patella Schltr., H. retusa Dalzell, and H. venusta Schltr. We discuss the morphological evidence that supports the reduction of these genera into Hoya. Among characters supporting such a position is the presence of a pellucid margin on the pollinia of Absolmsia, Madangia, Micholitzia, and Hoya that is absent on the pollinia of Dischidia. Absolmsia and Madangia have a staminal corona with outer and inner lobes, similar to that of Hoya. While the outer corona processes of Absolmsia and Micholitzia are free and revolute, as in most species of Hoya, those of Madangia are laterally fused forming a continuous skirt resembling the corona of certain species of Hoya. The flowers of Micholitzia are superficially similar to those of Dischidia in its urceolate corolla, but the staminal corona with revolute outer processes decidedly links Micholitzia to Hoya. The new combination H. inflata (P. I. Forst., Liddle & I. M. Liddle) L. Wanntorp & P. I. Forst. is proposed. For Micholitzia obcordata N. E. Br., the name H. yuennanensis Hand.-Mazz. has nomenclatural priority and should therefore be used when including M. obcordata in Hoya.
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| 7. |
- Wanntorp, Livia, 1968-
(författare)
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Phylogeny and biogeography of Gunnera
- 2002
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The angiosperm genus Gunnera consists of 30-40 species mainly distributed in Africa, New Zealand, Tasmania, South America, the Malay Archipelago and Hawaii. Because of its distribution in almost all parts of the Southern Hemisphere and to its 90 millions year's history on Earth, Gunnera is especially interesting for its biogeography. By analysing sequences of rbcL and the rps16 intron from the chloroplast, and the ribosomal DNA ITS region from the nuclear genome, and by studying the morphology of 27 species representing all six subgenera of Gunnera (Panke, Misandra, Milligania, Gunnera, Pseudogunnera and Ostenigunnera), a wellsupported phylogeny for the genus was obtained for the first time. The biogeography of Gunnera was then examined in the light of the phylogeny. The positions of G. herteri and G. perpensa, from northern South America and Africa, respectively, were well supported in the phylogeny and interpreted as what remains of the species that once inhabited the large area along the Guinea fracture zone to which both Africa and northern South America belong. The remaining species were divided into two clades; one including the Malayan/Australian/New Zealand species and the other with the American and Hawaiian species. Within the first clade, the position of the Malayan G. macrophylla sister to the species from New Zealand and Tasmania was interpreted as a vicariance event. In contrast, G. cordifolia from Tasmania, nested within the species of New Zealand can be explained by dispersal from New Zealand. In subgenus Panke, the positions of G. mexicana and of the Hawaiian species, respectively, as sisters to the southern South American species suggests a northern origin for the subgenus. Though the resolution within subgenera Milligania and Panke is not yet complete, a good framework for future studies has been established.The phylogeny allows also for the first time other taxonomic and morphological types of studies. The South American G. manicata is the most commonly cultivated species. The identity and the origin of this species have long been controversial. The molecular phylogeny of Gunnera clarified that the place of origin of G. manicata is Brazil. The specimens from Colombia, which mistakenly goes under the name G. manicata, represent a new species.On the apex of the rhizomes of all the South American and Hawaiian species (subgenus Panke), there are large scales which have been the focus of discussions during the past two centuries. The scales have sometimes been interpreted as cataphylls and sometimes as stipules. Botanists have also searched for structures homologous to these scales in other species of the genus. According to the present results, the scales in Panke are of leafy origin and homologous to two cataphylls on the top of the stolons of the plants of subgenera Pseudogunnera and Milligania. The scales are also homologous to the ochrea found on the stolons in subgenus Misandra.
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| 8. |
- Wanntorp, Livia
(författare)
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Pollinaria of Hoya (Marsdenieae, Apocynaceae) : shedding light on molecular phylogenetics
- 2007
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Ingår i: Taxon. - 0040-0262 .- 1996-8175. ; 56:2, s. 465-478
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Tidskriftsartikel (refereegranskat)abstract
- First molecular phylogenies of Hoya failed to reveal many intrageneric relationships, emphasizing the need to find additional phylogenetic characters. Thirty-five species, covering the morphological and geographic variation of Hoya, were examined using light and scanning electron microscopy (SEM). Thirteen phylogenetically informative characters were scored and studied in the light of an available phylogenetic tree. Species attributed to the Acanthostemma-group share pollinaria with obliquely elongate pollinia on broad-winged caudicles, synapomorphies that also link H. anulata and H. lacunosa to this group, the latter found in a disparate position in the phylogenetic tree. The pollinaria of H. sussuela fit well with those of the other species of section Eriostemma in having pollinia with twisted caudicles, a square corpusculum, and without pellucid margins. The absence of pellucid margins on the pollinia, is also characteristic of H. mitrata and H. darwinii. Australian/New Guinean species generally have obovate pollinia basally protruding outwards and thick rhomboid corpuscula, supporting a monophyletic Australian/New Guinean clade, as suggested by phylogenetic studies. Hoya australis from Australia and H. albiflora from New Guinea have identical pollinaria indicating the possibility that these taxa are conspecific, as also shown in the phylogenetic tree. Several of the examined characters of the pollinaria, of Hoya are useful in inferring phylogenetic relationships, indicating the utility of pollinarium morphology in this genus.
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| 9. |
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