Phylogeny of theCyclanthaceae

The affinities ofCyclanthaceae are discussed, and it is concluded that the sister-group to this family is most probablyPandanaceae. A hypothesis of generic relationships inCyclanthaceae, based on cladistic methods, is presented. Bootstrap analysis and Bremer support (decay index) have been used to test the strength of individual clades, and the result is compared with previously made phylogenetic analyses. TheSphaeradenia group (Chorigyne, Stelestylis, Sphaeradenia, andLudovia) is supported as monophyletic and acceptably resolved, while theAsplundia group (remaining genera inCarludovicoideae) may be paraphyletic, with largely uncertain relationships. A formal recognition of these groups is therefore not justified. The probable character evolution inCarludovicoideae is discussed.     

A comparative study of the distribution and density of stomata in the British flora

The distribution of stomata over both leaf surfaces may affect both the photosynthetic rate and water use efficiency of species, implying that species with different photosynthetic and water requirements may also have different stomatal distributions. A database containing data on the distribution of stomata on the leaves of 469 British plant species was used to look for relationships between stomatal distribution (including both location on the leaf and density) and both habitat and morphological variables. Statistical models were applied to the data that minimized any effects that phylogenetic constraints may have had on the data.
Hypostomaty is common in woody species, species which typically occur in shaded habitats and species with large or glabrous leaves. Amphistomaty, however, predominates in species which occur in non-shaded habitats, species with small, dissected or hairy leaves, and in annual species. Amphistomaty, therefore, tends to occur in species where CO₂ may be limiting photosynthesis (unshaded environments), or where there are structures to prevent water loss from the leaf (e.g. hairs). Hypostomaty, however, occurs in slow-growing species (e.g. trees), species with leaves which have large boundary layers (large or entire leaves) and in species where CO₂ is unlikely to limit photosynthesis (shaded habitats).     

The impact of epistatic selection on the genomic traces of selection

The rapid accumulation of genomic data has led to an explosion of studies searching for signals of past selection left within DNA sequences. Yet the majority of theoretical studies investigating the traces of selection have assumed a simple form of selection, without interactions among selectively fixed sites. Fitness interactions—‘epistasis’—are commonplace, however, and take on a myriad of forms ( Whitlock et al. 1995 ; Segrèet al. 2005 ; Phillips 2008 ). It is thus important to determine how such epistasis would influence selective sweeps. On p. 5018 of this issue, Takahasi (2009) explores the effect of epistasis on genetic variation neighbouring two sites that interact in determining fitness, finding that such epistasis has a dramatic impact on the genetic variability in regions surrounding the interacting sites.     

Biogeographic area relationships in southern New Zealand: a cladistic analysis of Lepidoptera distributions

ABSTRACT. Recently, attention has been directed toward the application of cladistic techniques to reconstruct the history of areas from species distribution data. In this study, hypotheses of area relationships for southern New Zealand are generated from lepidopteran distribution data analysed at two taxonomic levels. Data are shown to possess cladistic structure and area relationships presented here are consistent with the geological history of the southern region of New Zealand. Our results suggest a recolonization of inland lowland regions from the south following a period of extinction during the early Pliocene. Analysis of selected data including only flightless or locally endemic species resulted in little resolution of area relationships but topologies were significantly congruent with a total species dataset. Hypotheses generated from this study are open to testing with congruence analysis using independent species phylogenies.     

Development of microsatellite markers in the grey‐crowned babbler (Pomatostomus temporalis)

The grey‐crowned babbler (Pomatostomus temporalis) is a cooperative breeding bird species in which nonbreeding helpers of both sexes care for the young of breeding individuals. To measure the genetic relatedness between breeders and their offspring and helpers, we developed nine microsatellite markers. Most of the loci were highly polymorphic. These loci will be useful in understanding the evolution and maintenance of cooperative breeding and helping behaviour in this species.