Phylogeography and counter-intuitive inferences in island biogeography: evidence from morphometric markers in the mobile butterfly Maniola jurtina (Linnaeus) (Lepidoptera, Nymphalidae)

Distribution of mobile organisms on near-continent islands is mainly shaped by factors operating over ecological rather geological time. However, the phylogeography of single species has the potential to expose historical factors at work. In the present study, West Mediterranean populations of the butterfly Maniola jurtina are studied using geometric morphometrics. The distribution of the two well established lineages ( Maniola jurtina jurtina in the Atlanto–Mediterranean area and Maniola jurtina janira in the Central–Eastern-Mediterranean area) on 12 islands and the adjoining continents are compared. The south-western lineage unexpectedly occurs on islands close to shores occupied by the eastern lineage. We have modelled the distribution of the lineages using three different hypotheses: (1) a contemporary isolation model, which predicts lineage occupancy of islands is linked to relative distances from neighbouring continental areas; (2) a refugial hypothesis, which predicts one lineage to be the ancestral one for the whole region studied, and then successively replaced over part of it; (3) a changing geography hypothesis, which predicts the two lineages to have evolved in their currently occupied areas, continuously sourcing islands subsequent to the Würm maximum glaciation. Of the three models, the refugial hypothesis is most highly correlated with the observed pattern, suggesting that Mediterranean islands may function as refugia during cold periods, much as the three mainland peninsulas of Iberia, Italy and Greece are known to have done. Thereafter, hybridization on the nearest and smallest islands has occurred, with the entire process supporting the notion of the joint influence of factors in ecological and geological time.  © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 98 , 677–692.     

The Inositol Lipids of Paramecium tetraurelia and Preliminary Characterizations of Phosphoinositide Kinase Activity in the Ciliary Membrane

Inositol glycerolipids make up less than 10% of total phospholipids of Paramecium tetraurelia cells. Unlike inositol lipids found in mammalian and other cell types, these lipids from Paramecium lack arachidonic acid. It was demonstrated that kinase and possibly phosphatase enzymes that interconvert phosphatidylinositol (PI), phosphatidylinositol phosphate (PI-P) and phosphati-dylinositol-bis-phosphate (PI-P₂) exist in ciliary membranes of this ciliate. When exogenous soybean PI and [γ-³²P]ATP were provided as substrates, isolated cilia preparations exhibited PI and PI-P kinase activities as demonstrated by the incorporation of radiolabel into PI-P and PI-P₂. Kinase activity was activated by millimolar [Mg²⁺] and inhibited by millimolar [Ca²⁺]. Significant inhibition of kinase activity in the presence of unlabeled excess ATP suggested that ATP is the preferred phosphate donor for this reaction. Of 4 suborganellar fractions of isolated cilia, the membrane fraction had the greatest kinase activity indicating that the enzyme(s) is membrane-associated     

Functional innovation through vestigialization in a modular marine invertebrate

Few studies show how morphological vestigialization may facilitate functional innovation. Fewer still describe the co‐occurrence of the derived and more ancestral structures in the same genetic individual. In the present study, we explore that rare instance in a modular (colonial) marine invertebrate. Using laser scanning confocal microscopy with fluorescent staining and behavioural observations, we describe homologous structures in polymorphic modules (zooids) in the bryozoan Bugula flabellata and document the occurrence of previously unreported retractor and circular muscles in the more derived module, the bird's‐head avicularium. In the evolution of a sessile feeding zooid to a moveable nonfeeding zooid with sensory and grasping functions, transformations were effected in the food‐capture apparatus, orificial structures, musculature, and sensory structures. We expand on and clarify previous reports of homologies between ancestral and derived modules in bryozoans and argue that vestigialization and augmentation of homologous structures were coincident with functional innovations in the avicularium. The present study offers rare evidence for the evolution of functional innovation through vestigialization. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 104 , 63–74.