In phylogenetics, the crown group of a collection of species consists of the living representatives of the collection together with their ancestors back to their last common ancestor as well as all of that ancestor's descendants. It is thus a clade, a group consisting of a species and all its descendents.
The name was given by Willi Hennig, the formulator of phylogenetic systematics, as a way of classifying living organisms relative to extinct ones. Though formulated in the 1970s, the term was not commonly used until its reintroduction in the 2000s by Graham Budd and Sören Jensen.
Read more about Crown Group: Contents of The Crown Group, Other Groups Under The Crown Group Concept, Palaeontological Significance of Stem- and Crown Groups, Stem-groups in Systematics
Famous quotes containing the words crown and/or group:
“no thread
Of cloudy silver sprinkles in your gown
Its venom of renown, and on your head
No crown is simpler than the simple hair.”
—Wallace Stevens (1879–1955)
“We begin with friendships, and all our youth is a reconnoitering and recruiting of the holy fraternity they shall combine for the salvation of men. But so the remoter stars seem a nebula of united light, yet there is no group which a telescope will not resolve; and the dearest friends are separated by impassable gulfs.”
—Ralph Waldo Emerson (1803–1882)