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:
“a sorrow’s crown of sorrow is remembering happier things.
Drug thy memories, lest thou learn it, lest thy heart be put to proof,
In the dead unhappy night, and when the rain is on the roof.”
—Alfred Tennyson (1809–1892)
“He hung out of the window a long while looking up and down the street. The world’s second metropolis. In the brick houses and the dingy lamplight and the voices of a group of boys kidding and quarreling on the steps of a house opposite, in the regular firm tread of a policeman, he felt a marching like soldiers, like a sidewheeler going up the Hudson under the Palisades, like an election parade, through long streets towards something tall white full of colonnades and stately. Metropolis.”
—John Dos Passos (1896–1970)