Dictionary Definition
derived adj
1 determined by mathematical computation; "the
calculated velocity of a bullet"; "a derived value" [syn: calculated]
2 formed or developed from something else; not
original; "the belief that classes and organizations are secondary
and derived"- John Dewey [ant: underived]
User Contributed Dictionary
English
Pronunciation
Adjective
- Of, or pertaining to, conditions unique to the descendant species of a clade, and not found in earlier ancestral species.
- In the context of "systematics|comparable|archaic": Possessing features believed to be more advanced or improved than those other organisms.
- product of derivation
Translations
Of conditions unique to the descendant
species
Possessing features believed to be advanced
See also
Verb form
derived- past tense and participle of derive.
Extensive Definition
In phylogenetics, a trait is
derived if it is present in an organism, but was absent in the last
common ancestor of the group being considered.
For the sake of precision, the term "derived" is
preferred to "advanced," a term which may inaccurately imply
superiority. Simplicity is often secondarily derived - for example,
the absence of leaves in the whisk fern Psilotum is a
result of their secondary loss, and when considered in the context
of ferns as a whole, is a derived trait. Likewise, the primitive
character state for birds (i.e. the state possessed by their last
common ancestor) is flight, which was secondarily lost by penguins
and dodos.
Whether or not a trait is considered derived
depends on the group in question. For example, Among the tetrapods,
having five fingers is the primitive trait - as their last common
ancestor bore a five-digit hand. However, amongst the vertebrates,
five fingers is a derived trait, as the last common ancestor to the
vertebrates did not even bear fingers.