Studies on the comparative physiology of the heart

From the time of Harvey until the middle of the nineteenth century practically nothing that was fundamental had been added to our knowledge of the physiology of the heart - a circumstance which is the more remarkable considering the stimulus to investigation in this very field which the publication of Harvey's immortal work should have afforded. The mid-nineteenth century, however, saw the commencement of investigations along several distinct lines, the results of which were to lead to a greater advance in our knowledge of the heart in the succeeding sixty years than previous hundreds had witnessed. This new era, which we may take as having been initiated by the work of Remak, Stannius and the brothers Weber, has continued to the present day, and as it concerns aspects of cardiac physiology with which it is the business of this paper to deal the question of the cause of the heart beat and of the cause of the effects produced by the extrinsic regulatory nerves.The rapid and indeed sensational advance of endocrinology and the consequent demonstration of the comparatively simple chemical basis of some of the most complicated of physiological processes led to the evolution of a new views point and a new technique in physiological research - hormonic, indeed, in more senses than one. Investigations in this new field by this new technique left practically no organ in the body untouched and so the heart, in common with the other organs, came in for its due share of attention.Soon after the appearance of Loewi's work, which will be reviewed in a later section of this paper, articles appeared almost simultaneously from three different laboratories describing experiments which were interpreted as showing that the rhythmicity of cardiac tissue was due to the action on the otherwise non- rhythmic myocardium of substances r,roduced by, or at least acting through, the special (nodal) system of the heart.Thus Demoor, Professor of Physiology in the University of Brussels, showed that non-rhythmic portions of mammalian cardiac muscle could be made to beat rhythmically if bathed in Locke solution to which had been added an extract of the sinoauricular node, and he concluded from this that the automatic rhythmicity of the heart was dependent on the continuous action on the myocardium of what he called the "substances actives", produced by the sinoauricular node, and, as demonstrated later, found also in the node of Tawara, bundle of His, and the Purkinje tissue of the subendocardium.Haberlandt, of Innsbruck, working independently of Demoor and in ignorance of the latter's work, showed that the sinus venosus of the frog's heart produced a substance - " Herzhormon" - which would initiate rhythmic contractions in the long perfused and quiescent frog ventricle, and to which therefore the normal automaticity of the heart was presumed to be due.Finally, Zwaardemaker, of Utrecht, working mainly with the eel's heart, came to the conclusion as a result of experiments commenced as far back as 1916, that the automaticity of cardiac tissue was due to .the presence in the heart of substances which he called "Automatins" which were produced in various parts of the body by the action of the ß rays of potassium on an inactive precursor which he called "automatinogen ". These automatins were supposed to be concentrated in the special system of the heart, and to work, as it were, from this system as a base.Thus was initiated what has now generally come to be known as the work on the "heart hormones" - an inaccurate though convenient term by which to designate the various substances described by the different workers.It is the purpose of this paper to review the work of each of the three schools, to add the author's own observations, to discuss the whole critically, and, if possible, assess the value and significance of this work

Contributions to the study of histamine antagonists in man: (with additional papers)

The main part of this thesis consists, firstly, of a series of papers illustrating the development of the writer's quantitative approach to the study of the action of histamine antagonists in man; and, secondly, of a note concerning trials of antihistaminics, followed by the description of a pilot trial of one of these drugs. Some repetition has been unavoidable in the published accounts.The supporting part of the thesis consists of two papers, in order of their publication. The first describes some early work on the mode of action of autonomic nerves, and is followed by a short addendum. The second, and more important contribution, deals with the inactivation of adrenaline - thought, at that time, to be the transmitter of adrenergic nerve effects. It is followed by a short addendum extending some of the observations to various mammals, including man. The war interrupted this work, but it was resumed, and extended to include noradrenaline, when that substance became available. A second addendum summarises some of the more recent observations.This work, on histamine antagonists and on adrenaline and noradrenaline, is being continued. Some of the methods developed in it are being success- fully applied to related fields, both by the writer and by some of his pupils

Dwelling Poetically, Proceeding Orphically: The Platonic Tradition and the Heideggerian Humanism of Ernesto Grassi

Martin Heidegger exerted an immense influence over twentieth century thought by providing profound insights into the nature of Being as well as scathing social critiques, focused on the destructive force of late modern technological reductionism. As part of Heidegger’s project, he elaborated upon a sophisticated history of Being in which two great monsters of Platonism and Humanism are cast as Antichrist and False Prophet. Subsequently, however, his own student Ernesto Grassi argued that Renaissance Humanism was not a stepping stone towards subjectivism and technological thinking, but rather stood in conformity with the fundamental essence of Heidegger’s own project. This study seeks to perform the same service for the much maligned history of Platonic thinking. After reviewing the important details of the positions held by Heidegger and Grassi in the Introduction and Chapter One, I move on to an examination of the history of the interpretation of Plato in Chapter Two. Here I show that, when we approach Plato correctly, his thought conforms to insights later offered by Heidegger and Grassi. In the remaining chapters of the study, I demonstrate that this misunderstanding afflicts not only Plato himself, but it has also affected the interpretation of the entire Neoplatonic tradition. Thus, in Chapter Three, I show that Plotinus receives and expands upon the core insights which Plato possessed, and that Platonism’s role in the development of technological enframing has been gravely mistaken. In Chapter Four, I show how the later integration of Neoplatonic thought into some of the greatest Christian Platonists did nothing to eliminate these core insights of the Platonic tradition. Finally, in Chapter Five, I show that Marsilio Ficino, the Platonist painted by Grassi as the arch-villain who undermined the Heideggerian project of the Renaissance continued to maintain the fundamental insights of the Platonic tradition. Ultimately, therefore, Platonism, far from being the foundation of technological enframing in the modern era, is able to offer great assistance to the Heideggerian-Grassian project of renewing poetic and rhetorical speech as the foundation of philosophical thinking

Empirical dynamics of a small scale coastal upwelling region

The study investigates the dynamics of a small space scale (less than 10 km) coastal upwelling region at the temporal scales spanning hours to years. Three to four year time series data sets of, sea temperatures at different depths (2m, 5 m and 8,5 m) one kilometer offshore, of wind and of waves, obtained from Eskom for the Koeberg nuclear power station site study near Melkbosstrand (33° 41'S, 18° 26'E) were digitized on an hourly basis. An emphasis is placed on the study of the wind and sea temperature data, the latter being an unique data set in the South African context. The data were filtered into different frequency bands (<12,0 <0,5 <0,025 cpd). Simple statistics, linear correlation and spectral analysis were used to characterize these bands. Dominant temporal scales were identified as the seasonal, event (synoptic) and diurnal time scales. The characterization of the latter two time scales were supplemented with field work which inter alia measured: sea temperature profiles and transects; sea surface temperature distribution with the airborne radiation thermometry technique and Lagrangian currents

Sunburn and malignant melanoma.

We investigated the relationship between cutaneous malignant melanoma and multiple sunburns in the Queensland population. Interview data were gathered from 236 case-control pairs concerning their lifetime experience of severe sunburns, their occupational and recreational sun exposure, and their skin type. Excluding the lentigo maligna melanoma subtype, an association between multiple sunburns and melanoma was evident. After controlling for other major risk factors there was a significant dose-response relationship (P less than 0.05): the estimated relative risk associated with 2-5 sunburns in life was 1.5, and with 6 or more was 2.4. This observation extends the hitherto circumstantial evidence of a causal relationship between exposure to solar ultraviolet radiation and melanoma, and suggests that precautionary measures could prevent the development of this disease in a proportion of cases in fair-skinned populations

The non-abelian Born-Infeld action at order F^6

To gain insight into the non-abelian Born-Infeld (NBI) action, we study coinciding D-branes wrapped on tori, and turn on magnetic fields on their worldvolume. We then compare predictions for the spectrum of open strings stretching between these D-branes, from perturbative string theory and from the effective NBI action. Under some plausible assumptions, we find corrections to the Str-prescription for the NBI action at order F^6. In the process we give a way to classify terms in the NBI action that can be written in terms of field strengths only, in terms of permutation group theory.Comment: LaTeX, 31 pages, 30 figure

Hard X-ray emission from a flare-related jet

&lt;p&gt;&lt;b&gt;Aims:&lt;/b&gt; We aim to understand the physical conditions in a jet event which occurred on the 22nd of August 2002, paying particular attention to evidence for non-thermal electrons in the jet material.&lt;/p&gt; &lt;p&gt;&lt;b&gt;Methods:&lt;/b&gt; We investigate the flare impulsive phase using multiwavelength observations from the Transition Region and Coronal Explorer (TRACE) and the Reuven Ramaty High Energy Spectroscopic Imager (RHESSI) satellite missions, and the ground-based Nobeyama Radioheliograph (NoRH) and Radio Polarimeters (NoRP).&lt;/p&gt; &lt;p&gt;&lt;b&gt;Results:&lt;/b&gt; We report what we believe to be the first observation of hard X-ray emission formed in a coronal jet. We present radio observations which confirm the presence of non-thermal electrons present in the jet at this time. The evolution of the event is best compared with the magnetic reconnection jet model in which emerging magnetic field interacts with the pre-existing coronal field. We calculate an apparent jet velocity of ~500 km s-1 which is consistent with model predictions for jet material accelerated by the &lt;b&gt;J&lt;/b&gt; X &lt;b&gt;B&lt;/b&gt; force resulting in a jet velocity of the order of the Alfvén speed (~100–1000 km s-1).&lt;/p&gt

THE AMPHIBIAN TREE OF LIFE

The evidentiary basis of the currently accepted classification of living amphibians is discussed and shown not to warrant the degree of authority conferred on it by use and tradition. A new taxonomy of living amphibians is proposed to correct the deficiencies of the old one. This new taxonomy is based on the largest phylogenetic analysis of living Amphibia so far accomplished. We combined the comparative anatomical character evidence of Haas (2003) with DNA sequences from the mitochondrial transcription unit H1 (12S and 16S ribosomal RNA and tRNAValine genes, ø 2,400 bp of mitochondrial sequences) and the nuclear genes histone H3, rhodopsin, tyrosinase, and seven in absentia, and the large ribosomal subunit 28S (ø 2,300 bp of nuclear sequences; ca. 1.8 million base pairs; x¯ 5 3.7 kb/terminal). The dataset includes 532 terminals sampled from 522 species representative of the global diversity of amphibians as well as seven of the closest living relatives of amphibians for outgroup comparisons. The primary purpose of our taxon sampling strategy was to provide strong tests of the monophyly of all ‘‘family-group’’ taxa. All currently recognized nominal families and subfamilies were sampled, with the exception of Protohynobiinae (Hynobiidae). Many of the currently recognized genera were also sampled. Although we discuss the monophyly of genera, and provide remedies for nonmonophyly where possible, we also make recommendations for future research. A parsimony analysis was performed under Direct Optimization, which simultaneously optimizes nucleotide homology (alignment) and tree costs, using the same set of assumptions throughout the analysis. Multiple search algorithms were run in the program POY over a period of seven months of computing time on the AMNH Parallel Computing Cluster. Results demonstrate that the following major taxonomic groups, as currently recognized, are nonmonophyletic: Ichthyophiidae (paraphyletic with respect to Uraeotyphlidae), Caeciliidae (paraphyletic with respect to Typhlonectidae and Scolecomorphidae), Salamandroidea (paraphyletic with respect to Sirenidae), Leiopelmatanura (paraphyletic with respect to Ascaphidae), Discoglossanura (paraphyletic with respect to Bombinatoridae), Mesobatrachia (paraphyletic with respect to Neobatrachia), Pipanura (paraphyletic with respect to Bombinatoridae and Discoglossidae/Alytidae), Hyloidea (in the sense of containing Heleophrynidae; paraphyletic with respect to Ranoidea), Leptodactylidae (polyphyletic, with Batrachophrynidae forming the sister taxon of Myobatrachidae 1 Limnodynastidae, and broadly paraphyletic with respect to Hemiphractinae, Rhinodermatidae, Hylidae, Allophrynidae, Centrolenidae, Brachycephalidae, Dendrobatidae, and Bufonidae), Microhylidae (polyphyletic, with Brevicipitinae being the sister taxon of Hemisotidae), Microhylinae (poly/paraphyletic with respect to the remaining non-brevicipitine microhylids), Hyperoliidae (para/polyphyletic, with Leptopelinae forming the sister taxon of Arthroleptidae 1 Astylosternidae), Astylosternidae (paraphyletic with respect to Arthroleptinae), Ranidae (paraphyletic with respect to Rhacophoridae and Mantellidae). In addition, many subsidiary taxa are demonstrated to be nonmonophyletic, such as (1) Eleutherodactylus with respect to Brachycephalus; (2) Rana (sensu Dubois, 1992), which is polyphyletic, with various elements falling far from each other on the tree; and (3) Bufo, with respect to several nominal bufonid genera. A new taxonomy of living amphibians is proposed, and the evidence for this is presented to promote further investigation and data acquisition bearing on the evolutionary history of amphibians. The taxonomy provided is consistent with the International Code of Zoological Nomenclature (ICZN, 1999). Salient features of the new taxonomy are (1) the three major groups of living amphibians, caecilians/Gymnophiona, salamanders/Caudata, and frogs/Anura, form a monophyletic group, to which we restrict the name Amphibia; (2) Gymnophiona forms the sister taxon of Batrachia (salamanders 1 frogs) and is composed of two groups, Rhinatrematidae and Stegokrotaphia; (3) Stegokrotaphia is composed of two families, Ichthyophiidae (including Uraeotyphlidae) and Caeciliidae (including Scolecomorphidae and Typhlonectidae, which are regarded as subfamilies); (4) Batrachia is a highly corroborated monophyletic group, composed of two taxa, Caudata (salamanders) and Anura (frogs); (5) Caudata is composed of two taxa, Cryptobranchoidei (Cryptobranchidae and Hynobiidae) and Diadectosalamandroidei new taxon (all other salamanders); (6) Diadectosalamandroidei is composed of two taxa, Hydatinosalamandroidei new taxon (composed of Perennibranchia and Treptobranchia new taxon) and Plethosalamandroidei new taxon; (7) Perennibranchia is composed of Proteidae and Sirenidae; (8) Treptobranchia new taxon is composed of two taxa, Ambystomatidae (including Dicamptodontidae) and Salamandridae; (9) Plethosalamandroidei new taxon is composed of Rhyacotritonidae and Xenosalamandroidei new taxon; (10) Xenosalamandroidei is composed of Plethodontidae and Amphiumidae; (11) Anura is monophyletic and composed of two clades, Leiopelmatidae (including Ascaphidae) and Lalagobatrachia new taxon (all other frogs); (12) Lalagobatrachia is composed of two clades, Xenoanura (Pipidae and Rhinophrynidae) and Sokolanura new taxon (all other lalagobatrachians); (13) Bombinatoridae and Alytidae (former Discoglossidae) are each others’ closest relatives and in a clade called Costata, which, excluding Leiopelmatidae and Xenoanura, forms the sister taxon of all other frogs, Acosmanura; (14) Acosmanura is composed of two clades, Anomocoela (5 Pelobatoidea of other authors) and Neobatrachia; (15) Anomocoela contains Pelobatoidea (Pelobatidae and Megophryidae) and Pelodytoidea (Pelodytidae and Scaphiopodidae), and forms the sister taxon of Neobatrachia, together forming Acosmanura; (16) Neobatrachia is composed of two clades, Heleophrynidae, and all other neobatrachians, Phthanobatrachia new taxon; (17) Phthanobatrachia is composed of two major units, Hyloides and Ranoides; (18) Hyloides comprises Sooglossidae (including Nasikabatrachidae) and Notogaeanura new taxon (the remaining hyloids); (19) Notogaeanura contains two taxa, Australobatrachia new taxon and Nobleobatrachia new taxon; (20) Australobatrachia is a clade composed of Batrachophrynidae and its sister taxon, Myobatrachoidea (Myobatrachidae and Limnodynastidae), which forms the sister taxon of all other hyloids, excluding sooglossids; (21) Nobleobatrachia new taxon, is dominated at its base by frogs of a treefrog morphotype, several with intercalary phalangeal cartilages—Hemiphractus (Hemiphractidae) forms the sister taxon of the remaining members of this group, here termed Meridianura new taxon; (22) Meridianura comprises Brachycephalidae (former Eleutherodactylinae 1 Brachycephalus) and Cladophrynia new taxon; (23) Cladophrynia is composed of two groups, Cryptobatrachidae (composed of Cryptobatrachus and Stefania, previously a fragment of the polyphyletic Hemiphractinae) and Tinctanura new taxon; (24) Tinctanura is composed of Amphignathodontidae (Gastrotheca and Flectonotus, another fragment of the polyphyletic Hemiphractinae) and Athesphatanura new taxon; (25) Athesphatanura is composed of Hylidae (Hylinae, Pelodryadinae, and Phyllomedusinae, and excluding former Hemiphractinae, whose inclusion would have rendered this taxon polyphyletic) and Leptodactyliformes new taxon; (26) Leptodactyliformes is composed of Diphyabatrachia new taxon (composed of Centrolenidae [including Allophryne] and Leptodactylidae, sensu stricto, including Leptodactylus and relatives) and Chthonobatrachia new taxon; (27) Chthonobatrachia is composed of a reformulated Ceratophryidae (which excludes such genera as Odontophrynus and Proceratophrys and includes other taxa, such as Telmatobius) and Hesticobatrachia new taxon; (28) Hesticobatrachia is composed of a reformulated Cycloramphidae (which includes Rhinoderma) and Agastorophrynia new taxon; (29) Agastorophrynia is composed of Bufonidae (which is partially revised) and Dendrobatoidea (Dendrobatidae and Thoropidae); (30) Ranoides new taxon forms the sister taxon of Hyloides and is composed of two major monophyletic components, Allodapanura new taxon (microhylids, hyperoliids, and allies) and Natatanura new taxon (ranids and allies); (31) Allodapanura is composed of Microhylidae (which is partially revised) and Afrobatrachia new taxon; (32) Afrobatrachia is composed of Xenosyneunitanura new taxon (the ‘‘strange-bedfellows’’ Brevicipitidae [formerly in Microhylidae] and Hemisotidae) and a more normal-looking group of frogs, Laurentobatrachia new taxon (Hyperoliidae and Arthroleptidae, which includes Leptopelinae and former Astylosternidae); (33) Natatanura new taxon is composed of two taxa, the African Ptychadenidae and the worldwide Victoranura new taxon; (34) Victoranura is composed of Ceratobatrachidae and Telmatobatrachia new taxon; (35) Telmatobatrachia is composed of Micrixalidae and a worldwide group of ranoids, Ametrobatrachia new taxon; (36) Ametrobatrachia is composed of Africanura new taxon and Saukrobatrachia new taxon; (37) Africanura is composed of two taxa: Phrynobatrachidae (Phrynobatrachus, including Dimorphognathus and Phrynodon as synonyms) and Pyxicephaloidea; (38) Pyxicephaloidea is composed of Petropedetidae (Conraua, Indirana, Arthroleptides, and Petropedetes), and Pyxicephalidae (including a number of African genera, e.g. Amietia [including Afrana], Arthroleptella, Pyxicephalus, Strongylopus, and Tomopterna); and (39) Saukrobatrachia new taxon is the sister taxon of Africanura and is composed of Dicroglossidae and Aglaioanura new taxon, which is, in turn, composed of Rhacophoroidea (Mantellidae and Rhacophoridae) and Ranoidea (Nyctibatrachidae and Ranidae, sensu stricto). Many generic revisions are made either to render a monophyletic taxonomy or to render a taxonomy that illuminates the problems in our understanding of phylogeny, so that future work will be made easier. These revisions are: (1) placement of Ixalotriton and Lineatriton (Caudata: Plethodontidae: Bolitoglossinae) into the synonymy of Pseudoeurycea, to render a monophyletic Pseudoeurycea; (2) placement of Haideotriton (Caudata: Plethodontidae: Spelerpinae) into the synonymy of Eurycea, to render a monophyletic Eurycea; (3) placement of Nesomantis (Anura: Sooglossidae) into the synonymy of Sooglossus, to assure a monophyletic Sooglossus; (4) placement of Cyclorana and Nyctimystes (Anura: Hylidae: Pelodryadinae) into Litoria, but retaining Cyclorana as a subgenus, to provide a monophyletic Litoria; (5) partition of ‘‘Limnodynastes’’ (Anura: Limnodynastidae) into Limnodynastes and Opisthodon to render monophyletic genera; (6) placement of Adenomera, Lithodytes, and Vanzolinius (Anura: Leptodactylidae) into Leptodactylus, to render a monophyletic Leptodactylus; (7) partition of ‘‘Eleutherodactylus’’ (Anura: Brachycephalidae) into Craugastor, ‘‘Eleutherodactylus’’, ‘‘Euhyas’’, ‘‘Pelorius’’, and Syrrhophus to outline the taxonomic issues relevant to the paraphyly of this nominal taxon to other nominal genera; (8) partition of ‘‘Bufo’’ (Anura: Bufonidae) into a number of new or revived genera (i.e., Amietophrynus new genus, Anaxyrus, Chaunus, Cranopsis, Duttaphrynus new genus, Epidalea, Ingerophrynus new genus, Nannophryne, Peltophryne, Phrynoidis, Poyntonophrynus new genus; Pseudepidalea new genus, Rhaebo, Rhinella, Vandijkophrynus new genus); (9) placement of the monotypic Spinophrynoides (Anura: Bufonidae) into the synonymy of (formerly monotypic) Altiphrynoides to make for a more informative taxonomy; (10) placement of the Bufo taitanus group and Stephopaedes (as a subgenus) into the synonymy of Mertensophryne (Anura: Bufonidae); (11) placement of Xenobatrachus (Anura: Microhylidae: Asterophryinae) into the synonymy of Xenorhina to render a monophyletic Xenorhina; (12) transfer of a number of species from Plethodontohyla to Rhombophryne (Microhylidae: Cophylinae) to render a monophyletic Plethodontohyla; (13) placement of Schoutedenella (Anura: Arthroleptidae) into the synonymy of Arthroleptis; (14) transfer of Dimorphognathus and Phrynodon (Anura: Phrynobatrachidae) into the synonymy of Phrynobatrachus to render a monophyletic Phrynobatrachus; (15) placement of Afrana into the synonymy of Amietia (Anura: Pyxicephalidae) to render a monophyletic taxon; (16) placement of Chaparana and Paa into the synonymy of Nanorana (Anura: Dicroglossidae) to render a monophyletic genus; (17) recognition as genera of Ombrana and Annandia (Anura: Dicroglossidae: Dicroglossinae) pending placement of them phylogenetically; (18) return of Phrynoglossus into the synonymy of Occidozyga to resolve the paraphyly of Phrynoglossus (Anura: Dicroglossidae: Occidozyginae); (19) recognition of Feihyla new genus for Philautus palpebralis to resolve the polyphyly of ‘‘Chirixalus’’; (20) synonymy of ‘‘Chirixalus’’ with Chiromantis to resolve the paraphyly of ‘‘Chirixalus’’; (21) recognition of the genus Babina, composed of the former subgenera of Rana, Babina and Nidirana (Anura: Ranidae); (22) recognition of the genera Clinotarsus, Humerana, Nasirana, Pelophylax, Pterorana, Pulchrana, and Sanguirana, formerly considered subgenera of Rana (Anura: Ranidae), with no special relationship to Rana (sensu stricto); (23) consideration of Glandirana (Anura: Ranidae), formerly a subgenus of Rana, as a genus, with Rugosa as a synonym; (24) recognition of Hydrophylax (Anura: Ranidae) as a genus, with Amnirana and most species of former Chalcorana included in this taxon as synonyms; (25) recognition of Hylarana (Anura: Ranidae) as a genus and its content redefined; (26) redelimitation of Huia to include as synonyms Eburana and Odorrana (both former subgenera of Rana); (27) recognition of Lithobates (Anura: Ranidae) for all species of North American ‘‘Rana’’ not placed in Rana sensu stricto (Aquarana, Pantherana, Sierrana, Trypheropsis, and Zweifelia considered synonyms of Lithobates); (28) redelimitation of the genus Rana as monophyletic by inclusion as synonyms Amerana, Aurorana, Pseudoamolops, and Pseudorana, and exclusion of all other former subgenera; (29) redelimitation of the genus Sylvirana (Anura: Ranidae), formerly a subgenus of Rana, with Papurana and Tylerana included as synonyms

Is The Amphibian Tree of Life really fatally flawed?

Wiens (2007, Q. Rev. Biol. 82, 55–56) recently published a severe critique of Frost et al.\u27s (2006, Bull. Am. Mus. Nat. Hist. 297, 1–370) monographic study of amphibian systematics, concluding that it is “a disaster” and recommending that readers “simply ignore this study”. Beyond the hyperbole, Wiens raised four general objections that he regarded as “fatal flaws”: (1) the sampling design was insufficient for the generic changes made and taxonomic changes were made without including all type species; (2) the nuclear gene most commonly used in amphibian phylogenetics, RAG-1, was not included, nor were the morphological characters that had justified the older taxonomy; (3) the analytical method employed is questionable because equally weighted parsimony “assumes that all characters are evolving at equal rates”; and (4) the results were at times “clearly erroneous”, as evidenced by the inferred non-monophyly of marsupial frogs. In this paper we respond to these criticisms. In brief: (1) the study of Frost et al. did not exist in a vacuum and we discussed our evidence and evidence previously obtained by others that documented the non-monophyletic taxa that we corrected. Beyond that, we agree that all type species should ideally be included, but inclusion of all potentially relevant type species is not feasible in a study of the magnitude of Frost et al. and we contend that this should not prevent progress in the formulation of phylogenetic hypotheses or their application outside of systematics. (2) Rhodopsin, a gene included by Frost et al. is the nuclear gene that is most commonly used in amphibian systematics, not RAG-1. Regardless, ignoring a study because of the absence of a single locus strikes us as unsound practice. With respect to previously hypothesized morphological synapomorphies, Frost et al. provided a lengthy review of the published evidence for all groups, and this was used to inform taxonomic decisions. We noted that confirming and reconciling all morphological transformation series published among previous studies needed to be done, and we included evidence from the only published data set at that time to explicitly code morphological characters (including a number of traditionally applied synapomorphies from adult morphology) across the bulk of the diversity of amphibians (Haas, 2003, Cladistics 19, 23–90). Moreover, the phylogenetic results of the Frost et al. study were largely consistent with previous morphological and molecular studies and where they differed, this was discussed with reference to the weight of evidence. (3) The claim that equally weighted parsimony assumes that all characters are evolving at equal rates has been shown to be false in both analytical and simulation studies. (4) The claimed “strong support” for marsupial frog monophyly is questionable. Several studies have also found marsupial frogs to be non-monophyletic. Wiens et al. (2005, Syst. Biol. 54, 719–748) recovered marsupial frogs as monophyletic, but that result was strongly supported only by Bayesian clade confidence values (which are known to overestimate support) and bootstrap support in his parsimony analysis was \u3c 50%. Further, in a more recent parsimony analysis of an expanded data set that included RAG-1 and the three traditional morphological synapomorphies of marsupial frogs, Wiens et al. (2006, Am. Nat. 168, 579–596) also found them to be non-monophyletic. Although we attempted to apply the rule of monophyly to the naming of taxonomic groups, our phylogenetic results are largely consistent with conventional views even if not with the taxonomy current at the time of our writing. Most of our taxonomic changes addressed examples of non-monophyly that had previously been known or suspected (e.g., the non-monophyly of traditional Hyperoliidae, Microhylidae, Hemiphractinae, Leptodactylidae, Phrynobatrachus, Ranidae, Rana, Bufo; and the placement of Brachycephalus within “Eleutherodactylus”, and Lineatriton within “Pseudoeurycea”), and it is troubling that Wiens and others, as evidenced by recent publications, continue to perpetuate recognition of non-monophyletic taxonomic groups that so profoundly misrepresent what is known about amphibian phylogeny