Polarity Of Character States Research Articles

A New Species of the Eleutherodactylus myersi (Anura: Leptodactylidae) Assembly from Ecuador

A New Species of the Eleutherodactylus myersi (Anura: Leptodactylidae) Assembly from Ecuador

Classification, relationships and distribution of the genera of Cyphaleini (Coleoptera : Tenebrionidae)

Examination of the external and internal adult skeletal morphology of Cyphaleini, an autochthonous Australian tribe, has resulted in a reduction in the number of genera from 33 to 19. Character-state polarity was established by comparison with the related outgroups, Heleini, Tenebrionini and Titaenini. Of the 40 characters considered phylogenetically important, 10 were selected to manually construct a cladogram serving as the basis for proposing hypotheses on relationships between genera, evolutionary trends and historical events leading to the present distribution of the group. Fifteen former generic names are considered to have an insufficient phylogenetic basis at generic level and are synonymised as follows (synonyms first): Timeneca Carter, 1914 = Mitrothorax Carter, 1914; Laonicus Haag-Rutenberg, 1878 = Opigenia Pascoe, 1869 = Platyphanes Westwood, 1849; Aphectus Carter, 1926 = Olisthaena Erichson, 1842; Ononyctus Carter, 1914 = Aethalides Bates, 1873 = Onosterrhus Pascoe, 1866 = Nyctozoilus Guérin-Méneville, 1830; Lygestira Pascoe, 1866 = Prophanes Westwood, 1849; Trisilus Haag-Rutenberg, 1878 = Anausis Bates, 1873 = Altes Pascoe, 1869 = Oremasis Pascoe, 1866 = Chartopteryx Westwood, 1841 = Cyphaleus Westwood, 1841; Pseudobolbophanes Kulzer, 1954 = Bolbophanes Carter, 1913; Cyclophanes Carter, 1913 = Hemicyclus Westwood 1841. One new genus, Chlorophanes, is proposed for the single species Trisilus punctipennis (Carter). The 82 new combinations proposed are listed in an appendix at the end of the paper.

Two New Species of Menetia from Northeastern Queensland, with Comments on the Generic Diagnoses of Lygisaurus and Menetia

The Australian skink genera Lygisaurus and Menetia are diagnosed on the basis of derived morphological characters. Menetia consists of the six species traditionally included therein (alanae, amaura, concinna, greyii, maini, and surda), plus three additional species (timlowi, koshlandae, and sadlieri). Menetia koshlandae and M. sadlieri are described as new and along with M. timlowi, most recently assigned to Lygisaurus, are shown to constitute a distinct subgroup within Menetia. A key is provided to all nine species of Menetia, and some notes are presented on reproduction, habitat and color for three species. Menetia is a group of small, ground-dwelling skinks occurring in arid, semi-arid, and seasonally dry habitats in Australia. Six species are currently recognized in the genus. Recently, a species originally described as M. timlowi by Ingram (1977), was reallocated to the genus Lygisaurus, a group of small, ground-dwelling skinks from mesic habitats in New Guinea and eastern Australia (Ingram and Covacevich, 1988). The reason for the reallocation was the realization that the species lacked the one uniquelyderived character of Menetia (supraoculars two instead of three or four) and its similarity to Lygisaurus burnettii. On re-examining a longknown but undescribed species of small skink from northeastern Queensland which closely resembles M. timlowi, I came to the conclusion that these two species are probably more closely related to Menetia than to Lygisaurus. Quite recently a single specimen of a second undescribed species also closely resembling M. timlowi has been discovered in the collections of the Queensland Museum. The purpose of this paper is to update the generic diagnoses of Lygisaurus and Menetia and to describe the two new species of Menetia. I also take the opportunity to provide some general notes on reproduction and habitat in three species of Menetia. MATERIALS AND METHODS The paravertebral scales were counted from the first scale falling wholly outside of an imagetia is a group of small, ground-dwelling i ks o curring in arid, semi-ari , and seasonl dry habi ats in Australia. Six species are rently recognized in the genus. Recently, a ecies originally described as M. timlowi by ram (1977), was realloca ed to the genus Lyisaurus, a group of small, ground-dwelling inary line drawn along the posterior edge of the thighs held perpendicular to the long axis of the body forward to and including the anteriormost nuchal. The supraand subdigital scales were counted on the fourth toe of the pes beginning in the former case with the first scale wholly on the toe, and in the latter case with the first transversely enlarged scale wholly on the toe. The posteriormost supraciliary was taken as the scale just lateral to the suture between the posteriormost supraocular and the anteriormost pretemporal. Nuchals were all the transversely enlarged paravertebral scales just posterior to the parietals. The presacral vertebrae were counted on X-rays. Limb length was measured along the posterior edge of the outstretched limb and including the claw. The polarity of character states was inferred by reference to the successively more distant outgroups: Eugongylus, the most generally primitive taxon in the Eugongylus group; southeast Asian Mabuya, the most generally primitive lygosomines, and Eumeces, the most generally primitive scincid (Greer, 1979). DIAGNOSES OF LYGISAURUS AND MENETIA B th Lygisaurus and Menetia are members of the Eugongylus group of lygosomine skinks (Greer, 1979), and both show the following derived character states vis a vis this group: supranasals absent; frontoparietals fused; postsupralabial single; external ear opening small; 268 This content downloaded from 157.55.39.243 on Thu, 06 Oct 2016 04:55:39 UTC All use subject to http://about.jstor.org/terms

Systematic embryology of the Araceae

Embryological data of systematic significance to the family Araceae are reviewed and analyzed, with special attention given to the determination of character-state polarities. Character-states considered primitive within the family include: presence of endothecial thickenings; binucleate, starchless pollen; anatropous, crassinucellate ovules with a thick nucellar cap and a single, unbranched funicular bundle; solanad or caryophyllad embryogeny; helobial endosperm development, with 2–8 cells in the chalazal chamber andab initio cellular division in the micropylar chamber; and endosperm present in ripe seeds. The phylogenetic implications of these conclusions are discussed, and promising avenues for future research are indicated.

Trends in the evolution of dicotyledonous seeds based on character associations, with special reference to pachychalazy and recalcitrance

VON TEICHMAN, I. & VAN WYK, A. E., 1991. Trends in the evolution of dicotyledonous seeds based on character associations, with special reference to pachychalazy and recalcitrance. The possible evolutionary status of the endothelium, hypostase, pachychalaza and the recalcitrant viability behaviour of seeds is considered in relation to bitegmy/unitegmy, crassinucellate/tenuinucellate ovules, nuclear/cellular endosperm development, large/small seed size, woody/herbaceous habit and tropical/temperate habitat. The presence of the endothelium, hypostase, pachychalaza and recalcitrance in dicotyledonous families is plotted against Dahlgren's system of classification. Results are compared with Sporne's advancement index for the various families. An endothelium is considered derived since it occurs more often in highly evolved superorders and is significantly associated with derived ovule and endosperm character states as well as with smaller seed size. A hypostase appears to be relatively ancestral and is significantly associated with pachychalazy and recalcitrance. The endothelium and hypostase have developed independently in many taxa and could be interpreted as being structurally and functionally analogous. Pachychalazy and recalcitrance are significantly associated with ancestral ovule character states and, at the species level, with large seed size (overgrown seed), woody habit and tropical habitat. The presence of pachychalazy, recalcitrance and associated large seed size are therefore regarded as ancestral character states of the dicotyledons. Consideration of currently accepted dicta on seed character state polarity, suggests a reversal in the evolutionary status of pachychalazy and large seed size.

Numerical, phenetic, and cladistic analyses: Problems and examples with Orthocladiinae (Diptera, Chironomidae)

Abstract Ninety‐one binary characters belonging to 58 genera and subgenera of Orthocladiinae (Diptera, Chironomidae) were filed in a matrix. Larval, pupal, adult male and female characters were analyzed. Trees obtained by different numerical (phenetic and cladistic) methods were compared. The set of selected characters seemed much more important for determining the final results than the numerical method used in computation. The polarity of character states did not substantially influence the final results. Consensus trees and the ≪bootstrap≫ method are the most promising techniques in resolving conflicting results obtained using different numerical methods or different sets of characters. In any case, time is probably better spent in character analysis than in testing the same data with different numerical methods. The largest set of characters available should be used, but both the redundant inclusion of correlated characters and an ≪a priori≫ injustified weighting should be avoided. The Hennigian trees...

Yugoslavian and other records of the Italian freshwater goby,Padogobius martensii, and a character polarization in gobioid fishes

Padogobius martensii, a freshwater gobiid fish from the Po basin and adjoining rivers of northeastern Italy, is now recorded from Yugoslavia (Dalmatia), and further rivers of the Italian Adriatic seaboard. Diagnostic features are summarized, with special reference to another freshwater goby of the area, Orsinigobius punctatissimus. The origin of the Dalmatian populations is discussed with reference to sea-level changes in the postglacial Adriatic basin. Meristic polymorphism in dorsal pterygiophore sequence is described in the various P. martensii populations and its significance noted for polarization of character states in this feature.

Phylogenetic considerations below the sectional level in Carex

Few estimates of phylogenetic relationship below the sectional level have been proposed within the genus Carex (Cyperaceae). The reasons for this include (1) poorly circumscribed sections (paraphyletic and polyphyletic), (2) uncertain relationships among sections, and (3) difficulty in objectively assessing character state polarities. The operational difficulties posed by points 2 and 3 can be overcome through the use of character compatibility analysis, if it can be demonstrated that the section under study is monophyletic (point 1). This technique enables the investigator to generate hypotheses of relationship while minimizing the number of prior assumptions. Hypotheses of phylogenetic relationship are presented for the taxa within Carex sections Phyllostachyae, Limosae, and Ceratocystis. The topologies of these unrooted networks are assessed using external data sets (chromosome numbers, etc.) that serve as tests of the hypotheses, and may allow for a posteriori determination of character state polarities. In sections Ceratocystis and Limosae, these analyses provide strong support for the notion that chromosome evolution in Carex proceeds in a linear stepwise fashion. The results for section Phyllostachyae contradict this notion. Synthesis of all available data, coupled with phylogenetic reconstruction, will enable caricologists to provide more convincing arguments about the nature, direction, and factors influencing character state change.

What is primitive in Mesembryanthemaceae? An analysis of evolutionary polarity of character states

Characters of the family Mesembryanthemaceae are investigated with respect to their state (primitive or derived) within this family. Out-group comparison with the closely related family Aizoaceae s.str. (excl. Mesembryanthemaceae) is used mainly, along with some other criteria. A tabulated survey of the characters discussed is provided. By combination of all characters considered as primitive, a morphotype (‘hypothetical ancestor’) of the Mesembryanthemaceae can be constructed. It is shown that no extant taxon possesses all features of this morphotype, but that all have acquired a number of derived characters. The possibility of the meronectary being a further synapomorphy of the family is discussed. A new synapomorphy for the subfamily Mesembryanthemoideae, namely the absence of expanding sheets on the valves of the hygrochastic capsule, is provided. The fundamental splitting of the Mesembryanthemaceae in two monophyletic subfamilies (Mesembryanthemoideae and Ruschioideae) is further supported by the results.

Errata: Molecular Studies of Thamnophiine Snakes: 1. The Phylogeny of the Genus Nerodia

Errata: Molecular Studies of Thamnophiine Snakes: 1. The Phylogeny of the Genus Nerodia

A CLADISTIC ANALYSIS OF LUCILIA CASS. (COMPOSITAE, INULEAE).

Abstract- Lucilia is a South American genus with 23 species restricted to disjunct areas in southeastern Brazil and along the Andes. Lucilia is a monophyletic group defined by the co-occurrence of six characters: herbaceous, alternate-leaved, pappus with scabrid bristles fused at the base into a ring, style-branches with sweeping hairs far down, capitula sessile, and aseptate-flagellate hairs. A dadogram is presented using 41 morphological and anatomical characters arranged into 26 transformation series. The polarity of character states was determined by outgroup comparison with the genus Berroa. The cladistic analysis showed extensive parallel evolution in a number of the more conspicuous characters and produced four unresolved trichotomies. However, basing the hierarchy of Lucilia on the branching pattern produced by cladistic analysis results in a more natural and predicitive classification. Lucilia is divided into three sections, Lucilia, Intermedieae (sect, nov), and Lucilioides [divided into two subsections, Subspicata (subsect. nov.) and Lucilioides]. The latter subsection is subdivided into two series, Lucilioides (ser. nov.) and Paralucilia. The Brazilian species of section Lucilia (acutijolia, linearifolia, ferruginea, tmentosa, recurva, nitens, and flagelliformis) form the most primitive group within the genus. The more derived species of the genus, section lucilioides (plicatifolia, catamarcensis, burkartii, subspkata, lopezmirandae, alpina, pickeringii, piptolepis, santamca, chilensis, schultzii, longifolia, radians, lehmanni, pusilla) are found in the Andes L. eriophora (section Intermedieae) from central Chile bridges these two groups. An explanation for the distribution of the genus is given, based on the ecology of the species in relation to theories of the geologic and climatic history of South America. The present pattern has been determined by the age, geographical range, and vicissitudes of the habitat in which each group occurs. In the Brazilian species group, the habitat is old, and has remained relatively stable since well before the Pleistocene. In the Andean species group, the habitat is young and has undergone numerous rapid alterations since its inception at the end of the Pliocene.

Biochemical Systematics and Evolution in the South American Turtle Genus Platemys (Pleurodira: Chelidae)

Phenetic and phylogenetic methods of analysis of allozymic data were used to determine relationships among members of the South American genus Platemys (P. pallidipectoris, P. spixii, P. macrocephala, P. radiolata, and P. platycephala). Two members of the related genus Phrynops (P. gibbus and P. rufipes) were used in the phylogenetic analysis to determine character state polarities. Comparison of the biochemical analyses to those from chromosomal and morphological data indicated a general concordance between the data sets and supports specific status for all five members of the Platemys group. Platemys platycephala appears to be the most divergent member of the genus.

Transformations in the extracranial course of the internal carotid artery in mammalian phylogeny

ABSTRACT Study of cranial-artery ontogeny reveals that three adult character states of the extra-cranial portion of the single mammalian internal carotid artery should be recognized: (1) transpromontorial—on the ventral surface of the promontorium of the petrosal bone, within the middle-ear cavity; (2) perbullar—within a canal in the medial wall of the auditory bulla; and (3) extrabullar—medial to the auditory bulla and middle-ear cavity. The phylogenetic transformation of these three character states is assessed via five criteria of testing morphocline polarity: (1) ontogenetic transformations; (2) commonality; (3) out group comparisons; (4) relative geochronologic age; and (5) “Form–function complexes.” Each of these “tests” supports the (laterally-placed) transpromontorial character state as primitive for Mammalia and Eutheria and the (medially-placed) perbullar and extrabullar states as derived conditions. This character-state polarity, the reverse of that generally accepted at present, supports one s...

Evolution of Menispermaceae

The polarity of character states of pollen, leaf, endocarp, seed, perianth, androecium, and gynoecium within the Menispermaceae is established on the basis of maximum correlation of characters. Instances of parallel evolution are explained. The origin and spread of the different genera, which manifest the various combinations of character states, are analysed in the light of the position of the continents during the Cretaceous and Tertiary periods. Menispermaceae seem to have originated in the lowlands of Africa during the Cretaceous when South America, Africa, Madagascar, and India were close to one another. Consequent to the continental drift each land mass might have carried with it some elements of the primitive Menispermaceae which must have eventually given rise to the neoendemics. The Sino–Japanese spread of this family seems to have been post-Himalayan. "Malesia" appears to be a secondary centre of diversification of taxa derived from India. Cissampelos, Cocculus, and Stephania seem to have originated in India and entered Africa during the Miocene. The Eocene endocarps of North America show affinity with those of the London Clay, which in turn were probably derived from the African stock. Among the extant species of North America only Calycocarpum lyonii seems to be the relic of the North American Tertiary flora and the rest appear to have been derived from east Asia.

DETERMINING CHARACTER POLARITY IN DIATOMS: AN ALTERNATIVE APPROACH

An alternative approach to the exclusive use of fossils in determining polarity of character states in diatoms is presented. Principles of the method known as outgroup comparison are discussed. An example using features of sexuality and the relative number and morphology of chloroplasts is offered, and differences in polarity suggested by the fossil and outgroup methods compared. Based on the outgroup criterion, oogamy and many, small discoid chloroplasts found in most centric diatoms are considered derived, while isogamy and few large, plate-like chloroplasts found in many pennate diatoms are considered primitive. Although the centric diatoms may occupy a position that stratigraphically pre-dates the pennates, they appear to possess derived features of sexuality and chloroplasts.

Morphology of the tongue in the tuatara, Sphenodon punctatus (Reptilia: Lepidosauria), with comments on function and phylogeny.

The morphology and histology of the tongue in Sphenodon punctatus are described and used to infer function and to determine character state polarities in lepidosaurs. The tongue lacks an anterior notch and is covered with filamentous papillae, including specialized gustatory papillae containing taste buds. Lingual glands are restricted to mucocytes covering the papillae. Three intrinsic tongue muscles are identified and shown to be discrete fiber systems and not merely elaborations of the M. hyoglossus. These muscles interact with a connective tissue skeleton, particularly three septal planes, to cause changes in tongue shape. Tongue protrusion is probably caused by hyoid protraction and contraction of posterior genioglossus fibers; retraction by hyoid retraction, hyoglossus contraction, and contraction of anterior genioglossus fibers. It is argued that taste is important in prey discrimination and possibly in courtship. Vomeronasal function is probably mediated by inhalation and not tongue movement. Insertion of genioglossus fibers into the buccal floor is a derived feature of lepidosaur tongues. Derived features of squamate tongues include an anterior bifurcation, a divided genioglossus comprising medial and lateral portions, ventral transverse and circular muscle fiber systems around the hyoglossus, and the presence of a median septum. The tongue of the squamate family Iguanidae shares many plesiomorphic features with Sphenodon.

Phylogenetic Reconstructions and Two New Varieties in the Andropogon virginicus Complex (Poaceae: Andropogoneae)

Phylogenetic reconstructions of the Andropogon virginicus complex were performed using Swofford's computer programs for maximum parsimony. Character state polarity is based on outgroup analysis of Andropogon sect. Leptopogon, to which the virginicus complex belongs. A pre- viously undetected synapomorphy justifies monophyly of this section. The data used in the recon- structions contain extensive homoplasy, and tree topology changes considerably with minor changes in the data. Nevertheless, the interrelationships of the taxa on the most parsimonious trees are largely concordant with the results of previous studies. These cladistic analyses do, however, sug- gest different evolutionary relationships for the subspecific taxa of A. virginicus and A. glomeratus, the two most complex species. As a consequence of these analyses, two new varieties, A. virginicus var. decipiens and A. glomeratus var. scabriglumus, are described. The Andropogon virginicus complex is a group of sexually reproducing perennials with a cen- ter of diversity on the Coastal Plain of the southeastern United States. Using an eclectic approach, combining phenetic and evolution- ary perspectives, I recognized 20 operational taxonomic units (OTUs) in the virginicus com-

THE WORLD GENERA OF TARSONEMIDAE (ACARI: HETEROSTIGMATA): A MORPHOLOGICAL, PHYLOGENETIC, AND SYSTEMATIC REVISION, WITH A RECLASSIFICATION OF FAMILY-GROUP TAXA IN THE HETEROSTIGMATA

AbstractA critical historical review of previous classifications and other work on tarsonemid and related mites is presented. General information concerning tarsonemids is reviewed, including the following: geographical distribution, life history, sex determination, sex ratio, copulation, adult female reproductive capacity and longevity, dispersal, food and host preferences, economic importance, and natural enemies.The generic and suprageneric taxa of Tarsonemidae, as known from the world fauna, are revised systematically and phylogenetically, based on a comprehensive assessment of morphology, ontogeny, and homology of tarsonemid structures, including their condition as found in other families of Heterostigmata. The fundamental systems of setal notation developed by Grandjean for the body and appendages of acariform mites are applied, including use for the first time of his special terminology for tarsal setae among heterostigmatic mites.Character transformation series (polarities) for the great majority of characters used in classifying tarsonemid mites are presented for the first time. The out-group method of comparison was used to propose character state polarities, based on the cladistic methodology of Hennig. The transformation series hypothesized for each of 157 characters are numbered, diagrammed in detail, and summarized in tabular form, both for the families of Tarsonemina and Heterostigmata in general and for the genera of Tarsonemidae in particular.Based on the above character transformation series, a tentative phylogeny of the genera of Tarsonemidae is proposed and illustrated by dendrograms. Three subfamilies are recognized, with Pseudotarsonemoidinae new subfam.being the sister-group of [Tarsoneminae + Acarapinae]. Seven tribes are recognized: the sister-groups Pseudotarsonemoidini and Tarsonemellini new tribes in Pseudotarsonemoidinae; the sister-groups Acarapini and Coreitarsonemini in Acarapinae; and sister-groups Steneotarsonemini and Hemitarsonemini new tribes, which together form the sister-group of Tarsonemini, in Tarsoneminae. Similar sister-groupings are proposed for the genera within each tribe, with 31 genera (7 new) and 5 subgenera allotted as follows. Pseudotarsonemoidini:UnunguitarsonemusBeer & Nucifora, 1965;PseudotarsonemoidesVitzthum, 1921;PolyphagotarsonemusBeer & Nucifora, 1965;NasutitarsonemusBeer & Nucifora, 1965; andTarsanonychusnew genus. Tarsonemellini:TarsonemellaHirst, 1923. Coreitarsonemini:AmcortarsonemusFain, 1971;AsiocortarsonemusFain, 1971; andCoreitarsonemusFain, 1970. Acarapini:AcarapisHirst, 1923. Hemitarsonemini:HemitarsonemusEwing, 1939;EotarsonemusDe Leon, 1966; and questionablyHeterotarsonemusSmiley, 1969. Steneotarsonemini:SteneotarsonemusBeer, 1954 (including subgeneraParasteneotarsonemusBeer & Nucifora, 1965, new status;MahunkacarusVainshtein, 1979; andNeosteneotarsonemusTseng & Lo, 1980, new status),Ogmotarsonemusnew genus,Suskianew genus,Phytonemusnew genus,DendroptusKramer, 1876, new status; andAcaronemusLindquist & Smiley, 1978. Tarsonemini:FungitarsonemusCromroy, 1958;RhynchotarsonemusBeer, 1954;Deleonianew genus,CeratotarsonemusDe Leon, 1956;DaidalotarsonemusDe Leon, 1956;IponemusLindquist, 1969;Pseudotarsonemusnew genus;SuctarsonemusMahunka, 1974;XenotarsonemusBeer, 1954;NeotarsonemoidesKaliszewski, 1984; andTarsonemusCanestrini & Fanzago, 1876 (including subgeneraChaetotarsonemusBeer & Nucifora, 1965, new status; andFloridotarsonemusAttiah, 1970,new status). Tribal placement ofPseudacarapisnew genus is uncertain, though it belongs in Tarsoneminae.New generic synonymies include the following:NeotarsonemusSmiley, 1967 objectively underPolyphagotarsonemusBeer & Nucifora, 1965;ParasteneotarsonemusBeer & Nucifora, 1965, andNeosteneotarsonemusTseng & Lo, 1980 subjectively under, but subgenera of,SteneotarsonemusBeer, 1954;PraeacaronemusKaliszewski & Magowski, 1985 subjectively underAcaronemusLindquist & Smiley, 1978;DitarsonemoidesKaliszewski, in prep. subjectively underNeotarsonemoidesKaliszewski, 1984;LupotarsonemusBeer & Nucifora, 1965,MetatarsonemusAttiah, 1970, andCheylotarsonemusTseng & Lo, 1980 subjectively underTarsonemusCanestrini & Fanzago, 1876; andChaetotarsonemusBeer & Nucifora, 1965, andFloridotarsonemusAttiah, 1970 subjectively under, but subgenera of,TarsonemusCanestrini & Fanzago, 1876. Newly designatednomina nudaarePunctatutarsonemusNucifora, 1964, referred toIponemusLindquist, 1969, andLupotarsonemusBeer & Nucifora, 1965, referred toTarsonemusCanestrini & Fanzago, 1876.Descriptions are provided of the subfamily Tarsonemoidea and of all family-group taxa of Tarsonemidae. A key to the adult females, and to the adult males and larvae so far as they are known, together with diagnoses, detailed descriptions, and habitus figures, are presented for the genera and subgenera of Tarsonemidae. Definitions of each genus- and family-group taxon, based primarily on apomorphies, are also given in the section on phylogenetic relationships. Remarks on the distribution, habitats, habits, and other taxonomic and nomenclatorial aspects are given under each genus, followed by a world list of nominate species thought to belong to each genus, and indication of material examined. Descriptions of type-species, either new or inadequately described previously, are given for genera and subgenera as follows:Nasutitarsonemus brontispaeBeer & Nucifora, 1965;Tarsanonychus emblematusn.sp.;Steneotarsonemus(Neosteneotarsonemus)arcticusn.sp.;Ogmotarsonemus erepsisn.sp.;Suskia mansonin.sp.;Pseudotarsonemus eueidesn.sp.;Neotarsonemoides adaeKaliszewski, 1984;Tarsonemus(Floridotarsonemus)scaberAttiah, 1970.Based on transformation series of the same characters mentioned above, a tentative phylogeny of Tarsonemidae and other families of Tarsonemina and Heterostigmata is proposed. A sister-grouping of Tarsonemidae and Podapolipidae is strongly supported apomorphically, with Pyemotoidea being the sister-group of Tarsonemoidea. Pygmephoroidea is strongly supported as the sister-group of [Pyemotoidea + Tarsonemoidea]. Of special note is a series of successive out-group relationships to [Pygmephoroidea + Pyemotoidea + Tarsonemoidea] of Trochometridiidae, then Dolichocybidae, then Heterocheylidae, and finally the Tarsocheylidae as the out-group of all other families of Heterostigmata. Each of the latter four families, therefore, warrants superfamilial status, with Trochometridiidae and Dolichocybidae beingoutsideof Pygmephoroidea and Pyemotoidea, respectively. The Tarsonemina is strongly supported apomorphically as a subcohort. However, Heterocheyloidea appears to represent a sister-group to Tarsonemina rather than to Tarsocheyloidea, such that a grouping of Heterocheyloidea with Tarsocheyloidea, to form a subcohort Tarsocheylina, would be paraphyletic.

ON DR CARLQUIST'S DEFENCE OF PAEDOMORPHOSIS

woody, as he (1962, 1980) maintains. States of characters may be primitive: suites of characters, that is individual organisms, are widely, but not universally, held to be acted on by natural selection. In an elegant series of papers, Harper and his co-workers (see Burdon, 1980) have made an extremely convincing case for there being very high levels of selection within plant species, yet it can be cogently argued in a zoological context, as it has long been in a botanical one (e.g Arber, 1920, p. 131), that any particular character-state may be in no way 'adaptive' (Gould and Lewontin, 1979). In an important review of the evolutionary polarity of character-states, Stevens (1980) has drawn attention to the apparently repeated trends of morphological variation within large genera and families of angiosperms. Such trends are listed by Ehrendorfer (1973) and have been discussed by Corner (1967). An example in overall morphology or plant architecture is provided by the survey of trees in the work of Halle, Oldeman and Tomlinson (1978), where, within families of angiosperms, the same 'models' of construction have been achieved again and again, that is, at least some of these models represent grades of organization. Using currently held views of evolution, it can be argued that the earliest angiosperms must have possessed a suite of characters which suited them to the Cretaceous environment apparently dominated by ferns and gymnosperms: the elucidation of that suite has been the goal of those who seek the possible ancestors from scrutiny of the known fossils (Takhtajan, 1969) or hypothesize from the correlations of character states in those modern angiosperms which seem to be evolving rapidly (Stebbins, 1974). Apparently very reasonably, it has been argued that the answer will only be found in the fossil record (Hughes, 1974) and a reconsideration of the Cretaceous fossil record (see Doyle, 1978) has led to the recognition of pollen and leaf character-states now typical of the groups of

Evolutionary Polarity of Character States

Various criteria have been used in recent literature to decide whether a given character state is primitive or derived. The problems are similar in botany and zoology. The present review emphasizes the botanical literature, in which there has been no general examination of the validity of the criteria since Spome's excellent review (149). Many of the criteria that Spome rejected as being inadequate have since crept back in to use; the criterion that he favored, correlation of characters, is of doubtful utility; and a criterion that he did not discuss, character state distribution, has since become widely used, but in two very different ways. Many of the criteria are interrelated, and several depend on further, generally unstated criteria; criteria are often used in combinations, so that an author's actual procedure becomes unclear. Finally, a criterion rejected in one place in an article may be accepted elsewhere (sometimes in the same paragraph). Hence a reexam­ ination of the validity of the various proposed criteria is overdue. There is now considerable interest in various forms of cladistic or phylo· genetic classification in botanical circles [(22, 72, 91, 166) and references]. Although these approaches to classification are thought beneficial because of their explicit assumptions and procedures, it is ironic that the recent literature hardly mentions the crucial early step: the assignment of evolu­ tionary polarity (101) to character states-i.e. the decision about which character states in the taxa being examined are derived or apomorphous and which are primitive or plesiomorphous (the terms are defined below). That estimates of evolutionary relationships depend on the decision about which character states are derived was shown by Solbrig (145), who obtained different phylogenies when he used three different criteria for this decision.