Derived stem

Derived stems are a morphological feature of verbs common to the Semitic languages. In those languages, the vocabulary is based predominately on roots consisting of three or four consonants, wherein each root may be the basis for a number of conceptually related words. Each language features a number of set patterns for deriving verb stems from a given root. Stems from the same root represent separate verbs, albeit often semantically related, and each is the basis for its own conjugational paradigm.

In each language, one stem is canonically associated with the ordinary active voice, while each of the others is canonically associated with the passive voice, the causative, the intensive, the reflexive, etc., or some combination thereof.

For example, both in Arabic and in Hebrew, many words that have a meaning related to writing contain the root K-T-B (in Hebrew, when the letter B does not come at the beginning of a word, it may sound like a V). Thus:

Derive

Derive or derived may refer to:

See also

Synapomorphy

In phylogenetics, a synapomorphy is a shared derived character or trait state that distinguishes a clade from other organisms. In other words, it is an apomorphy shared by members of a monophyletic group, and thus assumed to be present in their most recent common ancestor. The word synapomorphy, coined by German entomologist Willi Hennig, is derived from the Greek words σύν, syn = shared; ἀπό, apo = away from; and μορφή, morphe = shape.

Discussion

A derived character is a character that is derived from an ancestral character over evolutionary history. Derived characters are used in determining phylogenetic relationships. In phylogenetics, a derived character of a clade that has been inherited from a common ancestor and distinguishes the clade from other potentially related organisms is called a "synapomorphy" – a shared ("syn") character that sets the clade apart ("apo").

The concept of synapomorphy is relative to a given clade in the tree of life. What counts as a synapomorphy for one clade may well be a primitive character or plesiomorphy at a less inclusive or nested clade. For example, the presence of mammary glands is a synapomorphy for mammals in relation to tetrapods, but is a plesiomorphy for mammals in relation to one another, e.g., rodents and primates.