Clado

Part of speech: noun, adjective

Definitions

1. A branching or splitting in a line of descent, typically in relation to evolutionary biology
2. a term used to categorize groups based on shared characteristics or ancestral lineage
3. a concept involving the classification of organisms within a phylogenetic tree structure

Etymology: "Clade" is a term from biology, coined in 1958 by the British zoologist Julian Huxley, who needed a name for a group of organisms descended from a single common ancestor. He took it from the Greek "klados," meaning "branch" or "twig," the same image that gives us the idea of a family tree with its limbs spreading from a single trunk. The word was built to fit a new way of classifying life. Earlier systems grouped species by outward resemblance or by ranks like order and family, which did not always match actual descent. Cladistics, the method that sorts organisms by shared ancestry, needed a neutral term for any such branch, and "clade" filled that role without implying a fixed rank. Any group that includes an ancestor and all of its descendants counts as one, whether it contains a few species or millions.

Synonyms: branch, branching