A branching identification key within
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. ...
(the practice and science of
categorization
Categorization is the ability and activity of recognizing shared features or similarities between the elements of the experience of the world (such as Object (philosophy), objects, events, or ideas), organizing and classifying experience by a ...
or
classification Classification is a process related to categorization, the process in which ideas and objects are recognized, differentiated and understood.
Classification is the grouping of related facts into classes.
It may also refer to:
Business, organizat ...
), is a presentation form of a
single-access key
In phylogenetics, a single-access key (also called dichotomous key, sequential key, analytical key, or pathway key) is an identification key where the sequence and structure of identification steps is fixed by the author of the key. At each point i ...
where the structure of the decision tree is displayed graphically as a branching structure, involving lines between items.
[Winston, J. 1999. Describing Species. Columbia University Press.] Depending on the number of branches at a single point, a branching key may be
dichotomous
A dichotomy is a partition of a whole (or a set) into two parts (subsets). In other words, this couple of parts must be
* jointly exhaustive: everything must belong to one part or the other, and
* mutually exclusive: nothing can belong simultan ...
or
polytomous
An internal node of a phylogenetic tree is described as a polytomy or multifurcation if (i) it is in a rooted tree and is linked to three or more child subtrees or (ii) it is in an unrooted tree and is attached to four or more branches. A tr ...
.
In a diagnostic key, the branching structure of the key should not be mistaken for a phylogenetic or cladistic branching pattern.
All single-access keys form a decision tree (or graph if
reticulation exists), and thus all such keys have a branching structure. "Branching key" may therefore occasionally be used as a synonym for single-access key.
Examples of branching presentations
* Figure 19.5 in
* Page 8 in.
[The Natural History Museum 2000. Sorting creepy-crawlies. http://www.nhm.ac.uk/education/activities/school-activities/discovery-guides/assets/sorting.pdf]
References
{{DEFAULTSORT:Branching Identification Key
Taxonomy