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:
“So much of the trouble is because I am a woman. To me it seems a very terrible thing to be a woman. There is one crown which perhaps is worth it all—a great love, a quiet home, and children. We all know that is all that is worthwhile, and yet we must peg away, showing off our wares on the market if we have money, or manufacturing careers for ourselves if we haven’t.”
—Ruth Benedict (1887–1948)
“There is nothing in the world that I loathe more than group activity, that communal bath where the hairy and slippery mix in a multiplication of mediocrity.”
—Vladimir Nabokov (1899–1977)