title: The phylogeny of tRNA sequences provides evidence for ambiguity reduction in the origin of the genetic code.
authors.affiliation: Department of Biological Sciences, University of Southern California, Los Angeles 90089-1481.
authors.forename: W M
authors.initials: WM
authors.lastname: Fitch
authors.forename: K
authors.initials: K
authors.lastname: Upper
mesh_terms: D001483:Base Sequence; D005075:Biological Evolution; D005815:Genetic Code; D008957:Models, Genetic; D009690:Nucleic Acid Conformation; D010802:Phylogeny; D012343:RNA, Transfer / Q000235:genetics*
chemical_list: D012343:RNA, Transfer