. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11Materials and Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ....

Several authors have argued recently that extensive taxon sampling has a positive and important effect on the accuracy of phylogenetic estimates. However, other authors have argued that there is little benefit of extensive taxon sampling, and so phylogenetic problems can or should be reduced to a few exemplar taxa as a means of reducing the computational complexity of the phylogenetic analysis....

Research has suggested the existence of a pathological dissociative taxon. However, relatively little is known about this taxon. This study examined the 2-month retest stability of this taxon--together with other measures of dissociation and the Big Five--in a sample of 465 undergraduates. Contrary to expectation, taxon scores were only modestly stable and were substantially less stable than th...

It is well known among phylogeneticists that adding an extra taxon (e.g. species) to a data set can alter the structure of the optimal phylogenetic tree in surprising ways. However, little is known about this "rogue taxon" effect. In this paper we characterize the behavior of balanced minimum evolution (BME) phylogenetics on data sets of this type using tools from polyhedral geometry. First we ...

The genus Phyllactinia is one of the members of Erysiphaceae (Erysiphales, Ascomycota) which parasitize several host plant families. This taxon is well characterized by having acicular appendages with bulbous swelling at the base and penicillate cells which are outgrowth of some ascoma wall cells. A number of challenges exist to distinguish species assigned to this taxon. This is because of a f...

Most organisms experience competition for resources, probably most of the time. As the structure and requirements of closely related species are generally liable to be more similar than in distantly linked species, Darwin suggested that the potential for competition was greater in the former. Since that time, studies have concentrated on interactions of either conspecifics or congeneric species...