Basics of Classification Taxonomy

Taxonomy is the practice and science of categorization or classification. A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. Among other things, a taxonomy can be used to organize and index knowledge (stored as documents, articles, videos, etc.), such as in the form of a library classification system, or a search engine taxonomy, so that users can more easily find the information they are searching for. Many taxonomies are hierarchies (and thus, have an intrinsic tree structure), but not all are. Originally, taxonomy referred only to the categorisation of organisms or a particular categorisation of organisms. In a wider, more general sense, it may refer to a categorisation of things or concepts, as well as to the principles underlying such a categorisation. Taxonomy organizes taxonomic units known as “taxa“ (singular “taxon“).“ Taxonomy is different from meronomy, which deals with the categorisation of parts of a whole. A phylogenetic tree, also known as a phylogeny, is a diagram that depicts the lines of evolutionary descent of different species, organisms, or genes from a common ancestor. Phylogenies are useful for organizing knowledge of biological diversity, for structuring classifications, and for providing insight into events that occurred during evolution. Furthermore, because these trees show descent from a common ancestor, and because much of the strongest evidence for evolution comes in the form of common ancestry, one must understand phylogenies in order to fully appreciate the overwhelming evidence supporting the theory of evolution. Tree diagrams have been used in evolutionary biology since the time of Charles Darwin. Therefore, one might assume that, by now, most scientists would be exceedingly comfortable with “tree thinking“--reading and interpreting phylogenies. However, it turns out that the tree model of evolution is somewhat counterintuitive and easily misunderstood. This may be the reason why biologists have only in the last few decades come to develop a rigorous understanding of phylogenetic trees. This understanding allows present-day researchers to use phylogenies to visualize evolution, organize their knowledge of biodiversity, and structure and guide ongoing evolutionary research. But what exactly is a phylogeny? Moreover, how should one read and interpret one of these diagrams? In an attempt to answer such questions, the following sections present a brief introduction to tree thinking. A more complete view of this subject can be developed by learning about how traits evolve along trees, how trees are reconstructed, and how trees are used to study various aspects of evolution. #phyliogeneticTree #Evolution #speciation #diagram #branchingInAPhylogeneticTree #Genetics #bilology #taxonomy #cladogram #populationGenetics #hawaiiIslands #founderEffect #geneticDrift #geneticVariation #taxa #clade #taxonomyClassification