Temperature dependence of fitness components in geographical populations of Drosophila melanogaster: changing the association between size and fitness

Contrary to the conventional wisdom 'bigger is better', evolution at high temperature invariably leads to small individuals in Drosophila melanogaster . Natural selection is known to be responsible, meaning that genotypes that are small because of adaptation to high temperature must have some temperature dependent fitness advantage. In this study we consider both preadult and adult fitness components, and show that large adults from a cold adapted population significantly outperform small adults from a warm adapted population only when tested at low temperature and low larval density. In all other conditions 'bigger is not necessarily better', meaning that environmental influences are capable of altering the association between size and fitness. Yet, 'smaller wasn't better either' under any condition, when considering the overall measure of fitness. Examination of individual fitness components revealed population by temperature interaction in preadult survival; this interaction is potentially capable of explaining the temperature specific advantage of small adult body size. At high temperature, the warm adapted population exhibits superior preadult survival while producing small adults. Geographical variation in adult body size seems to be the result of selection on larval growth and competitive strategies, resulting in alterations in the association between fitness components.  © 2003 The Linnean Society of London, Biological Journal of the Linnean Society , 2003, 80 , 717–725.     

A new species of Exostyles (Leguminosae, Papilionoideae, Swartzieae s.l.), from Paraná State, Brazil

A new species Exostyles godoyensis Soares-Silva & Mansano (Leguminosae, Papilionoideae, Swartzieae), endemic to Paraná state in southern Brazil, is described and illustrated. The new species is distinct from all the other species of Exostyles in having a leaf with up to five leaflets, while the other species have at least seven leaflets per leaf. The new species is distinct from Exostyles amazonica Yakovlev in its longer stamen filaments and ovary stipe and from E. glabra Vogel and E. venusta Schott by its shorter anthers. In addition to these morphological characters E. godoyensis has a disjunct geographical distribution.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 146 , 103–106.     

A new Spanish species of Tragopogon (Asteraceae: Lactuceae)

Tragopogon cazorlanum (Asteraceae: Lactuceae) is proposed as a new Spanish species with distribution restricted to the Baetic mountains (south-eastern Spain). Its morphological, palynological, chromosomal, biogeographical and ecological features are discussed, as well as its main relationships and differences with reference to other Spanish species of the genus.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 146 , 505–511.     

A review of the genus Semele (Ruscaceae) systematics in Madeira

The present study attempts to review the systematics of Semele (Ruscaceae) in Madeira, based on phenotypic diversity. The variation in some vegetative (climbing shoot, second-order branches or 'phylloclades') and sexual (inflorescence and flowers) characters was analysed in 115 plant specimens from 30 field populations, herbaria of the Costa collection and Madeira Botanical Garden (MADJ) and certain gardens. Thirty-one quantitative and qualitative characters have been utilized in the analysis. Kaiser–Meyer–Olkin (KMO) analysis indicates adequate sampling. Principal component analysis (PCA) reveals that the spatial distribution of individuals has a discontinuous behaviour. Principal coordinate analysis (PCO) utilizing the Gower coefficient on standardized data revealed a significantly discontinuous distribution of individuals, such that two different clusters can be defined. The Student's t -test and Tukey test on separate characters, when individuals were classified according to the Costa classification, confirms the significant differences between grouping accessions. This leads to the recognition of two species within the genus in Madeira. Literature and herbarium studies show that these two taxa are conspecific with Semele androgyna (L.) Kunth sensu stricto (s.s.) and Semele menezesi Costa sensu lato (s.l.) . A separated statistical analysis of the S. androgyna cluster shows the possible existence of additional subgroups. Based on field population distribution, ecological behaviour and variation in features, we propose the recognition of two species, S. androgyna (L.) Kunth and S. menezesi (Costa) Pinheiro de Carvalho, and two subspecies S. androgyna (L.) Kunth androgyna Pinheiro de Carvalho and S. androgyna (L.) Kunth pterygophora Pinheiro de Carvalho.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 146 , 483–497.