tree of life

Short definition from Wiktionary

Noun

1. 1
   A kind of tree, the arborvitae; an individual thereof.
2. 2
   A metaphor used to describe the phylogenetic relationships between organisms, both living and extinct; a diagram that shows those relationships, with a treelike appearance.
3. 3
   A term used in the Hebrew Bible that is a component of the world tree motif.
4. 4
   The central mystical symbol used in the Kabbalah of esoteric Judaism, also known as the ten sephiroth.