We present a stochastic model for the size of a taxon in paleobiology, in which we allow for the evolution of new taxon members, and both individual and catastrophic extinction events. The model uses ideas from the theory of birth and death processes. Some general properties of the model are developed, and a fuller discussion is given for specific distributions of the time between catastrophic ...

Angiostrongylus costaricensis is a zoonotic parasitic nematode that causes abdominal or intestinal angiostrongyliasis in humans. It is endemic to the Americas. Although the mitochondrial genome of the Brazil taxon has been published, there is no available mitochondrial genome data on the Costa Rica taxon. We report here the complete mitochondrial genome of the Costa Rica taxon and its genetic d...

Comparative phylogeographic studies often reveal disparate levels of sequence divergence between lineages spanning a common geographic barrier, leading to the conclusion that isolation was nonsynchronous. However, only rarely do researchers account for the expected variance associated with ancestral coalescence and among-taxon variation in demographic history. We introduce a flexible approximat...

The present study aims to have a comparative study of the results, from biological monitoring as well as conventional method, based on physico-chemical variables. Water quality index (WQI) and planktonic diatom metrics have been used to determine water quality and ecological conditions of the Dong Nai River (DNR) and Canonical Correspondence Analysis (CCA) to find out the main environmental var...

What is a voucher and why is it important in research? As a preserved specimen of an identified taxon deposited in a permanent and accessible storage facility, the voucher serves as the supporting material for published studies of the taxon and ensures that the science is repeatable. Vouchers are crucial in authenticating the taxonomy of an organism, as a tool for identifying localities of the ...

New propositions are made in order to implement the cladotypic taxonomic system. The term ‘taxon’ designates metapopulation lineages that evolved from a unique metapopulation lineage. In other words, a taxon is composed of a species that experienced a cladogenesis event, and all its descendants. A new formulation for the defi nition of particular taxa is proposed: a taxon is a species that evol...

The coaggregation ability of bacteria isolated from a freshwater biofilm was compared to those derived from the coexisting planktonic population. Twenty-nine morphologically distinct bacterial strains were isolated from a 6-month-old biofilm, established in a glass tank under high-shear conditions, and 15 distinct strains were isolated from the associated re-circulating water. All 44 strains we...

Planktonic sulfur oxidizers are important constituents of ecosystems in stratified water bodies, and contribute to sulfide detoxification. In contrast to marine environments, taxonomic identities of major planktonic sulfur oxidizers in freshwater lakes still remain largely unknown. Bacterioplankton community structure was analyzed in a stratified freshwater lake, Lake Mizugaki in Japan. In the ...