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...

The proliferation of benthic cyanobacteria has been observed in Lake Baikal since 2011 and is a vivid manifestation the ecological crisis occurring littoral zone. cyanobacterium Symplocastrum sp. formed massive fouling on all types substrates, including endemic sponges. strain BBK-W-15 (=IPPAS B-2062T), which was isolated from sponge 2015, used for further taxonomic determination. A polyphasic ...

The concept of a "potential taxon" as a nameand literature-related data area in botanical databases is introduced. A potential taxon is a name with taxon circumscription information attached to it by means of one or more literature references. As a compromise solution between linking information in database systems entirely to specimen data or only to accepted names, using potential taxa can ef...

Increasingly, biologists are constructing evolutionary trees on large numbers of overlapping sets of taxa, and then combining them into a ‘supertree’ that classifies all the taxa. In this paper, we ask how much coverage of the total set of taxa is required by these subsets in order to ensure that we have enough information to reconstruct the supertree uniquely. We describe two results — a combi...

Ecologists and paleontologists often rely on higher taxon surrogates instead of complete inventories of biological diversity. Despite their intrinsic appeal, the performance of these surrogates has been markedly inconsistent across empirical studies, to the extent that there is no consensus on appropriate taxonomic resolution (i.e., whether genus- or family-level categories are more appropriate...

The diving beetle genus Rhithrodytes Bameul, 1989 is endemic to areas surrounding the Western Mediterranean Basin, and currently includes six lotic species; three each in Europe North Africa. Here we describe a striking new species, pantaleonii sp. nov., discovered during recent fieldwork southwestern Sardinia. species differs markedly from only previously known Tyrrhenian Islands, R. sexguttat...

Linnaeus and other 18th Century naturalists practiced nomenclature in a way that associated taxon names more strongly with taxa (groups) than with the categorical ranks of the taxonomic (“Linnaean”) hierarchy. For those early naturalists, ranks functioned merely as devices for indicating hierarchical position that did not affect the application or spelling of taxon names. Consequently, taxa did...