A phylogenetic analysis of basal Anseriformes, the fossil Presbyornis, and the interordinal relationships of waterfowl

A phylogenetic analysis of 123 morphological characters of basal waterfowl (Aves: Anseriformes) and other selected avian orders confirmed that the screamers (Anhimae: Anhitn-idae) are the sister-group of other waterfowl (Anseres), and that the magpie goose (Anseranatidae: Anseranas semipalmata) is the sister group of other modern waterfowl exclusive of screamers (Anatidae sensu stricto). The analysis also supports the traditional hypothesis of the gallinaceous birds (Galliformes) as the sister group of the Anseriformes. Presbyornis, a fossil from the early Eocene of Wyoming and averred by Olson & Feduccia as showing that the Anseriformes were derived from shorebirds (Charadriiformes), was found to represent the sister group of the Anatidae. Associated hypotheses by Olson & Feduccia concerning the implications of Presbyornis for the phylogenetic relationships of flamingos (Phoenicopteriformes), the position of the Anhimidae within the waterfowl, relationships among modern Anatidae, and a plausible evolutionary scenario for waterfowl also are rejected. Analyses revealed that cranial characters were critical to the establishment of the Galliformes as the sister group of the Anseriformes; exclusion of the Anhimidae, especially in combination with Anseranas, also undermined the support for this inference. Placement of Presbyornis as the sister group of the Anatidae casts doubt on the role suggested by Feduccia of ‘transitional shorebirds' in the origin of modern avian orders, and calls into question the concept of ‘fossil mosaics’. The phylogenetic hypothesis is used to reconstruct an evolutionary scenario for selected ecomorphological characters in the galliform-anseriform transition, to predict the most parsimonious states of these characters for Presbyornis, and to propose a phylogenetic classification of the higher-order taxa of waterfowl. This re-examination of Presbyornis also is used to exemplify the fundamental methodological shortcomings of the intuitive approach to the reconstruction of phylogenetic relationships.     

Phylogeny of subfamily Epidendroideae (Orchidaceae) inferred from ndhF chloroplast gene sequences

This project undertakes the first molecular-based phylogenetic study of subfamily Epidendroideae (Orchidaceae). Approximately 1200 nucleotides (from the 3' half of the chloroplast gene ndhF for 34 orchid taxa and a lilioid monocot, Clivia miniata (Amaryllidaceae), were subjected to phylogenetic analysis using parsimony and maximum likelihood methods. Oryza sativa (Poaceae), a nonlilioid monocot, was designated as outgroup. Trees from both parsimony and maximum likelihood methods suggest that subfamily Epidendroideae is monophyletic, with Listera (Neottieae) as sister. Although subtribal relationships are typically well resolved and have strong branch support, intertribal relationships are generally poorly resolved. Perhaps this general lack of resolution among tribes reflects a rapid species radiation that coincided with anatomical, physiological, and anatomical adaptations that initiated large-scale epiphytism in the ancestral Epidendroideae. Six taxa in this study exhibit deletions that are not evenly divisible by three and result in extensive sequence frameshifts. For example, one deletion is 227 bp in length and is flanked by the short direct repeat sequence; TCAATAGGAATTTCTTTT. Multiple deletions and frameshifts suggest that ndhF may be a pseudogene, in at least some orchid taxa.     

What does morphology tell us about orchid relationships?—a cladistic analysis

A cladistic analysis of Orchidaceae was undertaken for 98 genera using 71 morphological apomorphies based on a reconsideration of previous character analyses and newly discovered variation. The equally weighted analysis found 60 000 most parsimonious trees with low consistency (CI = 0.29) but high retention (RI = 0.83). The strict consensus reveals a significant amount of structure, and most traditionally recognized subfamilies are supported as monophyletic, including the Apostasioideae, Cypripedioideae, Spiranthoideae, and Epidendroideae. Orchidoideae in the broad sense are paraphyletic, giving rise to spiranthoids. Vanilloids are sister to epidendroids, although exhibiting several states otherwise found only in clearly basal groups, such as Apostasioideae. The nonvandoid epidendroids are poorly resolved, due to a high degree of homoplasy. The vandoids appear to be monophyletic, contrary to recent molecular evidence, possibly due to repeated parallel development of the vandoid character suite. The importance of vegetative characters as evidence putatively independent from floral features is demonstrated in the placement of Tropidia. Implied weighting analysis of these data resulted in similar patterns at high levels, although the Orchidoideae and Spiranthoideae may each be monophyletic and the nonvandoid epidendroids are more resolved. The high degree of structure implied in previous orchid classifications must be reconsidered, given the poor resolution at lower levels in the present trees.     

Homologiekriterien oder Argumentationsverfahren?

In der herkömmlichen Formulierung der Homologiekriterien (vgl. Remane 1956: 58) wird das Wort “homolog” sowohl im Sinne von “gefügegleich” als auch “korrelierbar mit anderen Merkmalen” verwendet. Sie stellen Grundsätze auf und geben, ohne logische Unterscheidung, Wege an, diese Ziele zu erreichen. Als Ursache dieser Verwirrung wird die mangelhafte Unterscheidung der beiden Typuskonzepte nachgewiesen, welche in der Vergleichenden Morphologie einerseits und in der Taxonornie andererseits sowohl zur Musterfixierung als auch zur Mustererkennung Verwendung finden: Merkmalsleerer Gefügetypus und merkmalsgesättigter Korrelationstypus. Zu jedem der beiden Typuskonzepte gehört ein Verfahren, das angibt, wie mit den schwierigeren Fällen jeweils zu verfahren sei. Das Typologische Beweisverfahren wird näher dargestellt. Die in den Homologiekriterien niedergelegten Sätze können nach entsprechender Umformulierung in der aus Schema 10 ersichtlichen Weise auf die beiden Verfahren verteilt werden.     

Metaves,Mirandornithes, Strisores and other novelties – a critical review of the higher‐level phylogeny of neornithine birds

Recent hypotheses on the higher‐level phylogeny of modern birds are reviewed, and areas of agreement and major conflict are detailed, with emphasis being put on congruence among independent molecular and morphological data sets. Although molecular data significantly contributed to a better understanding of avian phylogeny, they do not seem to be free of homoplasy and caution is warranted in the interpretation of some results. The recently proposed ‘Metaves’ clade is likely to be an artefact of the β‐fibrinogen gene, and current molecular data do not yield well‐supported phylogenies for some groups whose interrelationships can be resolved with morphological evidence. There exists, however, congruent and strong molecular evidence for several novel clades that were not recognized by morphologists before, and to ease future discussions the terms Picocoraciae (non‐leptosomid ‘Coraciiformes’ and Piciformes) and Aequornithes (‘waterbird assemblage’) are introduced. Molecular studies further congruently recover some clades, which have not yet been adequately appreciated and are outlined in the present review.     

Phylogeny,natural groups and nemertean classification

Contemporary practice in the classification of nemerteans (phylum Nemertea) is critically discussed. It is argued that basing higher taxa on the existence of a unique combination of characters in a species (or genus) is unlikely to lead to monophyletic taxa, and that this approach should be abandoned in favour of a classification based on explicit hypotheses of phylogeny. These hypotheses should be based on all available characters and characters should not be excluded before the analysis. The classification should be based on a reconstruction of the phylogeny and reflect this phylogeny in an unambiquous way.     

Comparative embryonic development of the skeleton of the domestic turkey (Meleagris gallopavo) and other galliform birds

Ossification sequences are poorly known for birds in general, even for common domestic and experimental species. Such sequences constitute a rich source of data on character evolution, and may even provide phylogenetic information. It is not clear, however, what factors influence ossification sequences and what the relative importance of phylogeny is to the sequences. Galliformes constitute a good group to examine these variables. These birds are osteologically conservative, have precocial young, but have a broad spectrum of body sizes and incubation periods. Here, I describe the embryonic ossification of the skeleton in the domestic turkey (Meleagris gallopavo), and compare it to the domestic chicken (Gallus gallus) and the Japanese quail (Coturnix coturnix). Ossification sequences in this group are not affected by egg size or incubation period. They also appear to be independent of both the spatial location and the embryonic tissue from which the osteogenic cells originated. Accumulation of a wider sample of ossification sequences from more morphologically variable avian taxa will be necessary in order to test functional and phylogenetic effects.     

A multidisciplinary approach to the fine-systematics within Tisbe - an evaluation of morphological and molecular methods

Six species from the species-rich taxon Tisbe (Copepoda, Harpacticoida) were selected that could be reared in the laboratory as mass cultures. Phylogenetic relationships among these species were assessed by morphological studies of adults and larvae, DNA restriction site polymorphisms, allozymic, immunological distance, and lipid composition. Limits of scope and practicability of these analyses became apparent, as well as their potential and importance for future work in zoological systematics.     

The relationships of Heberdenia bahamensis and H. penduliflora (Myrsinaceae)

A morphological and anatomical investigation is presented of the two species of Heberdenia, H. bahamensis (Macaronesia) and H. penduliflora (Mexico). A cladistic analysis including 27 taxa of the Myrsinaceae and using Jacquinia (Theophrastaceae) and Manilkara (Sapotaceae) as outgroup was performed to provide a hypothesis of the relationships of the two species of Heberdenia. It was concluded that H. bahamensis and H. penduliflora are not more closely related to each other than either is to many other species of the Myrsinaceae, and that they should not be referred to the same genus. Heberdenia bahamensis appears to be most closely related to the Old World genera Pleiomeris, Embelia , and Grenacheria , whereas H. penduliflora is nested within Ardisia s. L , possibly being most closely related to the segregate genus Gentlea. It is suggested that H. penduliflora is probably best referred to a genus of its own.     

A phylogenetic analysis of subtribe Pleurothallidinae (Orchidaceae)

A cladistic analysis of subtribe, Pleurothallidinae (Orchidaceae) is based on 45 anatomical/ morphological characters. The ingroup members comprise 24 genera; the large genus Pleurothallis consists of two subgenera and ten species complexes. Three taxa representing subtribes Laeliinae and Arpophyllinae are designated as outgroup. Eight most parsimonious trees were discovered using computer assisted software (length = 230; CI = 0.27). The hypothesis that subtribe Pleurothallidinae has undergone a unilinear reduction in the number of pollinia is not supported by this study. Although the eight-pollinia state as represented by Octomeria apparently is plesiomorphic, the two-pollinia and four-pollinia states arose early in the phylogeny of the subtribe. Both two-and four-pollinia states subsequently reappeared as parallelisms. The six-pollinia state exhibited in Brachionidium is autapomorphic. This cladistic analysis suggests that Pleurothallis is not a natural genus and, perhaps may be divided into several discrete genera.