One of science's most popular metaphors — the "tree of life," with its evolutionary branches and roots, showing groups of bacteria on the bottom and multicellular animals on the higher branches — turns out to be a misnomer, UCLA molecular biologists report in the Sept. 9 issue of the journal Nature. "It's not a tree; it's actually a ring of life," said James A. Lake, UCLA professsor of molecular biology. "A ring explains the data far better." Lake initially titled the Nature article, "One Ring to Rule Them All." The ring of life has significant implications for eukaryotes (cells with nuclei), the group that includes all multicellular forms of life, such as humans, animals and plants.