1. The root of the universal tree and the origin of eukaryotes based on elongation factor phylogeny;Baldauf,1996
2. Root of the universal tree of life based on ancient aminoacyl-tRNA synthetase gene duplications;Brown,1995
3. Determining divergence times of the major kingdoms of living organisms with a protein clock;Doolittle;Science,1996
4. The phylogeny of tRNA sequences provides evidence for ambiguity reduction in the origin of the genetic code;Fitch,1987
5. Protein sequences in phylogeny;Goodman,1976