Molecular Phylogenies Support Homoplasy of Multiple Morphological Characters Used in the Taxonomy of Heteroscleromorpha (Porifera: Demospongiae)

Sponge classification has long been based mainly on morphocladistic analyses but is now being greatly challenged by more than 12 years of accumulated analyses of molecular data analyses. The current study used phylogenetic hypotheses based on sequence data from 18S rRNA, 28S rRNA, and the CO1 barcoding fragment, combined with morphology to justify the resurrection of the order Axinellida Lévi, 1953. Axinellida occupies a key position in different morphologically derived topologies. The abandonment of Axinellida and the establishment of Halichondrida Vosmaer, 1887 sensu lato to contain Halichondriidae Gray, 1867, Axinellidae Carter, 1875, Bubaridae Topsent, 1894, Heteroxyidae Dendy, 1905, and a new family Dictyonellidae van Soest et al., 1990 was based on the conclusion that an axially condensed skeleton evolved independently in separate lineages in preference to the less parsimonious assumption that asters (star-shaped spicules), acanthostyles (club-shaped spicules with spines), and sigmata (C-shaped spicules) each evolved more than once. Our new molecular trees are congruent and contrast with the earlier, morphologically based, trees. The results show that axially condensed skeletons, asters, acanthostyles, and sigmata are all homoplasious characters. The unrecognized homoplasious nature of these characters explains much of the incongruence between molecular-based and morphology-based phylogenies. We use the molecular trees presented here as a basis for re-interpreting the morphological characters within Heteroscleromorpha. The implications for the classification of Heteroscleromorpha are discussed and a new order Biemnida ord. nov. is erected.

Robert Graves

Robert Graves was a British writer who enlisted in August 1914. He fought at the Battle of Loos in 1915, and was wounded at the Somme in 1916. He published his first volumes of poems during the war, and his bestselling war memoir, Goodbye to All That, in 1929.

Research in Progress: Medical Research Council United Kingdom Refractory Asthma Stratification Programme (RASP-UK)

The UK Refractory Asthma Stratification Programme(RASP-UK) will explore novel biomarker stratificationstrategies in severe asthma to improve clinicalmanagement and accelerate development of newtherapies. Prior asthma mechanistic studies have notstratified on inflammatory phenotype and theunderstanding of pathophysiological mechanisms inasthma without Type 2 cytokine inflammation is limited.RASP-UK will objectively assess adherence tocorticosteroids (CS) and examine a novel compositebiomarker strategy to optimise CS dose; this will alsoaddress what proportion of patients with severe asthmahave persistent symptoms without eosinophilic airwaysinflammation after progressive CS withdrawal. There will be interactive partnership with the pharmaceutical industry to facilitate access to stratified populations for novel therapeutic studies.