Underlying Synapomorphies and Anagenetic Analysis

Evaluations of holomorphological similarities are based on synapomorphies, symplesiomorphies, convergence, and parallelisms as results of parallel selection and of underlying synapomorphies respectively. Only synapomorphies and underlying synapomorphies can show genealogical relationships. Distinctions between parallel selections and underlying synapomorphies are of major phylogenetic importance, while distinctions between different evolutionary histories (eu-parallelisms and pseudo-parallelisms) are not. The circumstance when underlying synapomorphies are of special phylogenetic importance has been termed unique inside-parallelism. Three such unique inside-parallelisms are found in the female genitalia of the Chironomidae, where they are shown necessary for the understanding of subfamily relationships. — The first minimum criterion for recognizing synapomorphy (Schlee 1971) is corrected to: It should be present within the whole group or clearly secondarily reduced an apomorphic taxa. It should not be present in the same formation in any taxon outside the group which can be regarded as a possible sister group. — The anagenetic component of the evolutionary processes can, following a cladistic analysis, be calculated by means of the adjusted evolution index assigning the different recognizable steps of trends or morphocline number from 1 to 2 and calculating the arithmetic mean of all numbers. Examples from Chaoboridae and Chironomidae support the cladistic diagrams and point out that different stages belong to differing "grades". Methods of numerical taxonomy may give a finer gradation of anagenetic levels.     

Grundsätze der phylogenetischen Systematik (Eine praxisorientierte Übersicht)

The essential elements of phylogenetic systematics in the sense of Hennig are emphasized: The search for synapomorphies based on a special method of comparative morphology, and the aim of an exclusive use of synapomorphies for kinship proof and the basis of systematics. Special aspects of comparative morphology are: “Directed comparisons” steady reciprocal reflection between comparative morphological result and the system methodical efforts for the realization of distinctive details, comprehensive documentation and functional interpretation. This is equally true for recent and fossil forms. Most suitable for the method (in the sense defined above) are groups with numerous differentiated morphological characters, which can also be preserved in the fossil state. The less this is the case the less is the chance for achieving necessary numbers of well proven synapomorphies. Even so, it is not permitted—for those who want to perform phylogenetic systematics in the sense of Hennig—to use convergences, parallelisms or symplesiomorphies in the sense of “synapomorphies” as phylogenetic arguments for kinship relations. Numerous examples and diagrams demonstrate the methodological proceeding, and differences towards other methods of phylogenetical reconstruction and interpretation. Special attention is paid to direct and indirect conclusions drawn from fossils: Time of origin of characters, stem groups and *groups; predictions concerning the appearance (set of characters) of fossils and simultaneous existence of “neighbour groups” (sister groups, and more distantly related taxa).     

Phylogenetic analysis of the family Ariidae (Ostariophysi: Siluriformes), with a hypothesis on the monophyly and relationships of the genera

Ariid monophyly and intrafamilial relationships are investigated based on cladistic analysis of 230 morphological characters. Terminal taxa examined include whenever possible type‐species, or the most morphologically similar species to the type‐species of the nominal genera, and the largest possible number of species, including cleared and stained specimens, available in zoological collections. Previous hypotheses about monophyly of the Ariidae are strongly corroborated by new synapomorphies discovered in the present study. The subfamily Galeichthyinae and the remaining ariids are strongly supported by new morphological characters. The monotypic subfamily Bagreinae is recognized as the sister group to all nongaleichthyin ariids, supported by a large series of exclusive synapomorphies. A new concept of Ariinae is presented: the subfamily is found to be unequivocally monophyletic and includes all ariid genera, except Galeichthys and Bagre. New data supporting the monophyly of the genera included in the Ariinae are introduced and previous hypotheses of monophyly, species composition, morphological definition, and relationships are reviewed and discussed.     

Homology and errors

A recent review of the homology concept in cladistics is critiqued in light of the historical literature. Homology as a notion relevant to the recognition of clades remains equivalent to synapomorphy. Some symplesiomorphies are “homologies” inasmuch as they represent synapomorphies of more inclusive taxa; others are complementary character states that do not imply any shared evolutionary history among the taxa that exhibit the state. Undirected character‐state change (as characters optimized on an unrooted tree) is a necessary but not sufficient test of homology, because the addition of a root may alter parsimonious reconstructions. Primary and secondary homology are defended as realistic representations of discovery procedures in comparative biology, recognizable even in Direct Optimization. The epistemological relationship between homology as evidence and common ancestry as explanation is again emphasized. An alternative definition of homology is proposed. © The Willi Hennig Society 2012.     

The genera of Diopsidae (Insecta:Diptera)

Taxonomic characters which have been used in defining the genera of Diopsidae are discussed with special reference to the structure of the head and eyestalks. In consequence, the subdivisions of this family put forward by Hennig in 1965 are revised and extended, a new scheme of three subfamilies being proposed and a possible phylogenetic sequence of genera suggested.
A key for the identification of these subfamilies and current generic taxa is given.     

PHYLOGENY AND BIOGEOGRAPHY OF CONDEEUM GROUP (PROTURA: PROTENTOMIDAE)

Abstract  Using the Hennig 86 phylogenetic analysis program to analyse the taxa in genera related to Condeellum , the phylogenetic relationships among the species are schemed on the basis of potential synapomorphies of the adults, represented by 16 characters. The character evolution and the route of dispersal are also discussed. The cladistic biogeographic analysis is performed. The basal taxon Condeellum exhibits an Indo-Pacific distribution and the sister group Neocondeellum species exhibit a collective Oriental and Holarctic distribution. The distribution patterns and the vicariance events occurred in those areas are hypothesized.     

A cladistic analysis of the genera in the subfamily Pudicinae (Nematoda, Trichostrongyloidea, Heligmonellidae).

A parsimony analysis was performed on 37 specific taxa belonging to the subfamily Pudicinae (family Heligmonellidae), which contains parasites mainly from South American caviomorph rodents. Thirteen characters were used from the synlophe (rotation of axis, presence of carene, carene asymmetry, presence of comaretes, single ventral comarete length, ridge discontinuity, ventral ridge numbers, presence of a peculiar posterior synlophe, presence of supernumerary spines) and the male caudal bursa (relative length of rays 9 and 10, caudal bursa type, division of the dorsal ray, divergence of the 10th rays). The cladogram shows a consistency index of 1.0. The subfamily Pudicinae has two synapomorphies. Two suprageneric groups are recognized. Suprageneric group 1 shows one synapomorphy and contains Heligmostrongylus, Fuellebornema, Sciurodendrium and Pseudoheligmosomum; suprageneric group 2 shows two synapomorphies and contains Pudica, Acanthostrongylus, Justinema and Durettestrongylus. Five genera are defined on the basis of synapomorphies. The genera Heligmostrongylus, Sciurodendrium and Pudica which are considered paraphyletic, however, are retained due to lack of knowledge as to their relationships.     

康蚖群的系统发生和生物地理学的研究(原尾目:始蚖科)(英文)

应用HENNIG86系统发生分析程序,选择出成虫的有代表性的16个共同衍征,分析了与康蚖属相关各属的各个种类,得出了该类群的相关系统树。同时对特征的演化以及其扩散途径等也进行了讨论。文中还应用Page 1993的COMPONENT程序进行了生物地理学的分析;得到种类—地区支序图。其中康蚖属表现为典型的印度—太平洋分布型,而其姐妹群新康蚖属则兼有东洋区和全北区的分布型。至于分布地区的相互关系和在这些地区的分衍替代事件的发生等问题也作了初步的假想。     

Molecular phylogeny of Aphyocharacinae (Characiformes, Characidae) with morphological diagnoses for the subfamily and recognized genera

The subfamily Aphyocharacinae was recently redefined to comprise eight genera: Aphyocharax, Prionobrama, Paragoniates, Phenagoniates, Leptagoniates, Xenagoniates, Rachoviscus and Inpaichthys. This new composition, however, is partially incongruent with published results of molecular studies especially concerning the positions of Rachoviscus and Inpaichthys. Our goal was to investigate the monophyly of Aphyocharacinae and its interrelationships using three distinct phylogenetic methodologies: Maximum-likelihood and Bayesian analyses of molecular data, and also Parsimony analysis of a concatenated molecular and morphological dataset. All tree topologies recovered herein suggest that Rachoviscus, Inpaichthys and Leptagoniates pi do not belong to the Aphyocharacinae. The remaining aphyocharacin taxa analyzed do form a monophyletic group, which is itself composed of two subgroups being one comprised of Paragoniates, Phenagoniates, Leptagoniates and Xenagoniates, and the other comprised of Aphyocharax and Prionobrama. Internal relationships among these genera are statistically well supported and morphological synapomorphies are presented at the generic level. All tree topologies also indicate that Aphyocharacidium is closely related to Aphyocharacinae suggesting that it should be included in this subfamily. As recognized in the present study, the Aphyocharacinae is diagnosed by a single morphological synapomorphy: two dorsal-fin rays articulating with the first dorsal pterygiophore.     

The monophyly of the Characidiinae, a Neotropical group of characiform fishes (Teleostei: Ostariophysi)

Although virtually no phylogenetic evidence (in the sense advocated by Hennig, 1966) had been previously presented to support the monophyly of the Characidiinae, and most 'diagnostic' characters used by previous authors were found to be unacceptable in a cladistic classification, i t is still possible to diagnose the Characidiinae in a phylogenetic sense. This study revealed the existence of 13 synapomorphies supporting the monophyly of the group. Several of these synapomorphies, such as the modifications associated with the mesethmoid, the jaw bones, and the ribs of the fifth vertebra, are unique to the Characidiinae, thus providing a solid basis for recognizing the group as a monophyletic unit of characiform fishes. Demonstration of characidiin monophyly provides a solid foundation for further phylogenetic analysis of characidiin interrelationships, and higher level relationships among characiform fishes.     

Phylogeny, character evolution, and classification of Sapotaceae (Ericales)

We present the first cladistic study of the largely tropical family Sapotaceae based on both morphological and molecular data. The data were analyzed with standard parsimony and parsimony jackknife algorithms using equally and successive weighted characters. Sapotaceae are confirmed to constitute two main evolutionary lineages corresponding to the tribes Isonandreae‐Mimusopeae‐Sideroxyleae and Chrysophylleae‐Omphalocarpeae. The Sideroxyleae are monophyletic, Isonandreae are polyphyletic as presently circumscribed, and as suggested by the analyses, the subtribe Mimusopeae‐Mimusopinae has evolved within the Mimusopeae‐Manilkarinae, which hence is also paraphyletic. Generic limits must be altered within Sideroxyleae with the current members Argania, Nesoluma and Sideroxylon. Argania cannot be maintained at a generic level unless a narrower generic concept is adopted for Sideroxylon. Nesoluma cannot be upheld in a narrow or broad generic concept of Sideroxylon. The large tribe Chrysophylleae circumscribes genera such as Chrysophyllum, Pouteria, Synsepalum, and Xantolis, but the tribe is monophyletic only if the taxa from Omphalocarpeae are also included. Neither Chrysophyllum nor Pouteria are monophyletic in their current definitions. The results indicate that the African taxa of Pouteria are monophyletic and distinguishable from the South American taxa. Resurrection of Planchonella, corresponding to Pouteria section Oligotheca, is proposed. The African genera Synsepalum and Englerophytum form a monophyletic group, but their generic limits are uncertain. Classification of the Asian genus Xantolis is particularly interesting. Morphology alone is indecisive regarding Xantolis relationships, the combined unweighted data of molecules and morphology indicates a sister position to Isonandreae‐Mimusopeae‐Sideroxyleae, whereas molecular data alone, as well as successive weighted combined data point to a sister position to Chrysophylleae‐Omphalocarpeae. An amended subfamily classification is proposed corresponding to the monophyletic groups: Sarcospermatoideae (Sarcosperma), Sapotoideae (Isonandreae‐Mimusopeae‐Sideroxyleae) and Chrysophylloideae (Chrysophylleae‐Omphalocarpeae), where Sapotoideae circumscribes the tribes Sapoteae and Sideroxyleae as well as two or three as yet unnamed lineages. Morphological characters are often highly homoplasious and unambiguous synapomorphies cannot be identified for subfamilies or tribes, which we believe are the reason for the variations seen between different classifications of Sapotaceae. © The Willi Hennig Society 2005.     

Phylogenetic analysis of Eurytominae (Chalcidoidea: Eurytomidae) based on morphological characters

A phylogenetic study of the Eurytominae (Hymenoptera: Chalcidoidea) treating 178 taxa and based on 150 morphological characters is given. Several cladograms using the complete species sample, but obtained with different weightings, are presented. Local studies were also carried out to provide possible alternate topologies. The deep nodes of the trees were unstable and were never supported, but most of the superficial nodes were stable and robust. The results therefore provide support for a generic classification of the subfamily. The large genus Eurytoma– which includes about half of the described species of the subfamily – proved to be polyphyletic, and is redefined in a narrowed sense using putative synapomorphies. Bruchophagus and Prodecatoma were similarly redefined. The genera Philolema and Aximopsis are reconsidered and defined in a broader concept. A number of the species presently included in Eurytoma were transferred to these genera. Finally, 22 new generic synonymies are proposed and 33 species are transferred. The study also demonstrates that the Eurytomidae are polyphyletic. The results strongly support a sister‐group relationship between the Heimbrinae and the Chalcididae. The Rileyinae consist of two groups of unrelated taxa. A redefinition of the subfamily in a more restricted sense is supported by our results. The remaining group, consisting of the traditional Rileyinae, is included in the subfamily Buresiinae. Considered in this way they comprise the genera Buresium and Macrorileya, the latter being a senior synonym of Archirileya. The Buresiinae appear as the sister group of the Eurytominae. We propose to restrict the family Eurytomidae to these two taxa. This sister‐group relationship provides evidence to polarize the biological habits within Eurytominae. The common ancestor of Buresiinae is presumed to parasitize insects (mostly at the egg stage) living in grass stems. © 2007 The Linnean Society of London, Zoological Journal of the Linnean Society, 2007, 151 , 441–510.     

Adolf Naef (1883–1949), systematic morphology and phylogenetics

Several authors have highlighted methodological similarities between Naef’s systematic morphology and Hennig’s phylogenetic systematics. Whereas this may indicate an influence of Naef on Hennig, the relevant issues – such as the principle of generality in character analysis and the threefold parallelism of classification, ontogeny and the Fossil Record – reach back beyond Naef and Hennig and were widely discussed in the German systematics literature of the late 19th and early 20th Century. The same is true of conceptual issues, such as the discussion of the principle of monophyly, which was first introduced by Haeckel in 1866 ( Rieppel 2011b , J Zool Syst Evol Res 49 :1). In spite of methodological and conceptual agreements, Naef’s systematic morphology differed fundamentally from Hennig’s phylogenetic systematics. Naef emphasized the role of unbiased observation and the immediate acquaintance of the investigator with the phenomena given in nature as the basis of natural science in general, and of his hierarchy of types in particular. From the hierarchy of types, Naef derived through conceptual‐logical analysis the natural system, which above the species level forms a nested hierarchy of intensionally defined classes, denoted by general names. The historical‐causal interpretation of the hierarchy of types in turn offers insight into the hypothetical reality of phylogeny. Hennig in contrast denied the possibility of theory‐free observation, indeed of assumption‐free science in general, and on that basis put metaphysical issues above epistemology. Tying individuality to spatiotemporal location, historicity and causality, Hennig took not only species (as did Naef) but also supraspecific monophyletic taxa as individuals, denoted by proper names. From the species up, the phylogenetic system thus becomes a nested hierarchy of complex wholes of increasing degrees of complexity. Diagnostic characters of species or higher taxa can then no longer define classes (as in Naef’s natural system) but are thought to indirectly indicate the phylogenetic relations on which alone the phylogenetic system is to be based.     

The systematic position of Lauroiinae Skrjabin and Schikhobalova, 1951 (Nemata: Heterakoidea: Aspidoderidae), as revealed by the analysis of traits used in its diagnosis

During our work on biodiversity of parasites of mammals of the Neotropics we collected numerous nematodes assignable to species of the family Aspidoderidae (Nemata: Heterakoidea). These nematodes occur as parasites of the cecum and large intestine of marsupials, rodents and xenarthrans (armadillos) only in the New World. As aspidoderid nematodes have been little studied beyond their alpha taxonomy, it is the purpose of the present paper to apply phylogenetic systematic methods to more completely understand the evolutionary relationships of the included species. Members of the aspidoderid subfamily Lauroiinae have had very little work applied to their systematic relationships and no systematic revisions exist that include all recognized species. Diagnostic characters that define species in this subfamily include plate-like cuticular structures on the anterior end. Herein we define a suite of 52 characters derived from studies of specimens using both light and electron microscopy. Our phylogenetic systematic analysis included the eight known species in the Lauroiinae, seven of the Aspidoderinae and four outgroup taxa. The results indicate that the Lauroiinae is paraphyletic, that the cephalic plates on the anterior end are not synapomorphies for the Lauroiinae, and that structures forming the cordon are present in all species of the family. We propose elimination of the subfamily designations in the family Aspidoderidae and we show the utility of using additional characters in the diagnosis of the family and the genera within this family. The resulting hypothesis should serve as the foundation to understand the historical associations of the nematodes with the mammals they infect.
© The Willi Hennig Society 2008.     

An investigation into the cladistic relationships and monophyly of therocephalian therapsids (Amniota: Synapsida)

A comprehensive phylogenetic investigation was performed to elucidate the cladistic relationships and possible monophyly of therocephalian therapsids (Amniota: Synapsida). The phylogenetic positions of 30 therapsid taxa were examined under maximum parsimony, including 23 therocephalian genera. The analysis incorporated 110 cranial and postcranial characters in order to assess the interrelationships of basal therocephalians and eutherocephalians and their relationships to Cynodontia, representing the most complete review of therocephalian phylogeny to date. The analysis supports the hypothesis that Therocephalia represents the monophyletic sister taxon to Cynodontia, with as many as 15 morphological synapomorphies, in contrast with other recent analyses of lesser taxon sampling. The results also support the hypothesis that Scylacosauridae is more closely related to Eutherocephalia than to the basal therocephalian family Lycosuchidae, supporting a ‘Scylacosauria’ clade. The taxa suggested here to be neotenic forms (e.g. Ictidosuchoides and Ictidosuchops) are positioned near the base of a monophyletic Baurioidea. Neotenic development of the therocephalian feeding apparatus and evolutionary parallelism with cynodonts are suggested to have been important trends in the early evolution of baurioid therocephalians into the Late Permian and Early Triassic.     

Are monophyly and synapomorphy the same or different? Revisiting the role of morphology in phylogenetics

Species are groups of organisms, marked out by reproductive (replicative) properties. Monophyletic taxa are groups of species, marked out by synapomorphies. In Nelson’s analysis, monophyly and synapomorphy are identical relations. Monophyly and synapomorphy, however, are not equivalent relations. Monophyly is epistemically not accessible, whereas synapomorphy is epistemically accessible through character analysis. Monophyly originates with speciation, the two sister‐species that come into being through the splitting of the ancestral species lineage forming a monophyletic taxon at the lowest level of inclusiveness. Synapomorphy provides the empirical evidence for monophyly, inferred from character analysis in the context of a three‐taxon statement. If synapomorphy and monophyly were equivalent, phylogenetic systematists should find a single tree, instead of multiple equally parsimonious trees. Understanding synapomorphy as the relevant evidence for phylogenetic inference reveals a category mistake in contemporary phylogenetics: the treatment of morphological characters mapped onto molecular trees as synapomorphies and homoplasies. The mapping of morphological characters onto nodes of a molecular tree results in an empirically empty procedure for synapomorphy discovery. Morphological synapomorphies and homoplasies can only be discovered by morphological and combined analyses. The use of morphology in phylogenetic inference in general is defended by examples from Laurales and Squamata in particular. To make empirical evidence scientifically relevant in order to search for concordance, or dis‐concordance, of phylogenetic signal, is certainly more fruitful for phylogenetics than the uncritical mapping of morphological traits on a molecular scaffold. © The Willi Hennig Society 2010.     

A method for constraining the age of origination of derived characters

Fossils are the physical records of the history of morphological character evolution on Earth and can provide valuable information concerning the sequence and timing of origination of derived characters. Knowledge of the timing of origination of synapomorphies makes it possible to estimate when unobserved character changes occurred in the geological past. Here we present a method for estimating the temporal interval during which synapomorphies evolved. The method requires either direct inclusion of fossil taxa (with or without extant taxa) in cladistic analyses based on morphological or combined data, or indirectly using the “molecular scaffold approach.” Second, characters of interest are mapped on a most parsimonious tree and “minimum age node mapping” is used to place minimum ages on the nodes of the tree. Finally, characters of interest are evaluated for younger and/or older temporal constraints on the time of their origination; application of the older bound assumes ancestry of fossil terminals included in the tree. A key is provided herein describing the method. Among other applications, this approach has the potential to provide a powerful test of purported evolutionary cause–effect relationships. For example, the method has the ability to discover that derived characters of suggested adaptational significance may considerably pre‐date the cause(s) that are hypothesized to have favored their establishment. © The Willi Hennig Society 2007.     

Phylogeny of Celastraceae subfamily Hippocrateoideae inferred from morphological characters and nuclear and plastid loci

The phylogeny of Celastraceae subfamily Hippocrateoideae (～ 100 species and 19 genera in the Old and New World tropics) was inferred using morphological characters together with plastid (matK, trnL-F) and nuclear (ITS and 26S rDNA) genes. The subfamily is easily recognized by the synapomorphies of transversely flattened, deeply lobed capsules and seeds with membranous basal wings or narrow stipes together with bisexual, 5-merous flowers that generally have an extrastaminal disk and three stamens. Hippocrateoideae, like Salacioideae, are inferred to have an Old World origin. The narrow stipes of Neotropical species that are water-dispersed are inferred to be derived within the subfamily from ancestral species with wind-dispersed winged seeds. Helictonema, a monotypic genus endemic to tropical Africa, has a small, white, spongy aril that is located at the base of the seed wing and appears to be unique within Hippocrateoideae. Our inference that Helictonema is sister to the remaining members of the subfamily, considered in the context of Sarawakodendron being sister to Salacioideae, suggests that small arils and capsular fruit were primitive within both subfamilies. The aril became dramatically enlarged within Salacioideae, in which the fruits are berries, and lost entirely within Hippocrateoideae, in which the fruits are transversely flattened capsules. All five Old World taxa of Prionostemma and all eight currently recognized species within Simirestis are transferred to Pristimera, one South African variety of Pristimera is raised to species level, and all three taxa in Pristimera subgenus Trochantha are transferred to the new genus Trochantha.     

The monophyly of the subfamily Perisphaeriinae (Dictyoptera: Blattaria: Blaberidae)

A new definition of the subfamily Perisphaeriinae is given on the basis of five synapomorphies described from male and female genitalia and head morphology. The subfamily comprises eighteen genera: Bantua , Compsagis , Cyrtotria , Derocalymma , Ellipsica , Elliptoblatta , Gymnonyx , Hostilia , Laxta , Neolaxta , Perisphaeria , Perisphaerus , Pilema , Platysilpha , Poeciloblatta , Pseudoglomeris , Trichoblatta , Zuluia . Two genera are newly assigned to the Perisphaeriinae: Laxta and Neolaxta . Four genera are removed from the Perisphaeriinae: Aptera , Blepharodera , Eustegasta , Isoniscus . One new generic synonymy is proposed: Pronaonota as a synonym of Pilema . The subfamily has a large geographical range including tropical Africa, the Arabian Peninsula, Asia and Australia.