Taxonomic unit

Semifield tests offer the ability to observe or measure a suite of biological and physicochemical variables, as with the analysis of natural ecosystems. Usually, the focus is on structural measures such as the number of species and number of individuals per population (often lumped into higher taxonomic units), physicochemical parameters (e.g., dissolved oxygen, and pH including toxicant residues), and some microclimate parameters (e.g., evaporation in TMEs). 

The term pattern recognition is also used in the provenience literature We prefer the term numerical taxonomy for the whole process of grouping by numericai methods of taxonomic units into taxa on the basis of their character states ... 

The evolutionary history inferred from phylogenetic analysis is usually depicted as branching (treelike) diagrams. The correct evolutionary tree is a rooted tree that graphically depicts the cladistic relationships that exist among the operational taxonomic units... 

Taxonomy is the science of classification and has several functions. The first is to describe the species which is the basic taxonomic unit. The second is to catalogue these species into some arrangement enabling the relationships between species to be recognised. A third practical aspect is identification, that is, the matching of an unknown organism with a known species. 

Taxonomic units in protists and their relevance to the EiE debate... 

The third key issue is the everywhere element of the EiE statement. It is conceptually easy to show that a taxonomic unit (at whatever level) is globally distributed - i.e. is present in at least some suitable habitat in each biogeographic region of the world (e.g. Darling et al., 2004 Slapeta et al., 2006 Bass et al., 2007), although... 

Strains was analyzed by ARDRA and different genotyping was obtained in different temperature conditions. Each genotyping was conducted as an operational taxonomic unit (OTU). All the strains were analyzed with IbsrDNA and the sequence subjected to BLAST GeneBank analysis (Table 4 and Table 5). 

The third class of simple substances is that of the metals, semi-metals included. It is followed by the class of the earths, and the fifth and last class of column I is that of the alkalis. In eighteenth-century chemistry, these last three classes of column I constituted a particular taxonomic unit, that of the so-called bases of neutral salts, because the substances comprised were known to form salts with acids. This traditional unit is continued in the table. As to metals, the authors of the Methode followed the Swedish chemist Torbern Bergman and regarded, not the metals, but metal oxides (field III/c) as salifiable bases. ... 

Among the graphical means by which the table represents the taxonomic units and their relations, there is one by which it transgresses the ordinary classificatory structure of hierarchically nested taxonomic units. The table arranges the taxonomic units in the manner of a matrix. Because of this layout, all of the genera and species are related in a twofold way to other units of the same rank. Vertically, they are related to those taxonomic units that are of the same class—either the class of simple substances (column I) or one of the five classes of compounds (colunms II-VI). Horizontally, the species are related to their compounds when they are simple substances.Or, if they are compound substances, they are related to one of their components and at the same time to other compounds of this component. Thus the Tableau contains two different, but coordinated classificatory systems vertically, a system that distributes genera of substances into either the class of simple substances or into one of the five classes of compounds and horizontally, one that orders compounds according to one simple substance that these compounds have in common. ... 

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