Nobuyuki Uchikoga (uchiko@genji.c.u-tokyo.ac.jp)
Akira Suyama (suyama@dna.c.u-tokyo.ac.jp)
Department of Life Sciences,
The University of Tokyo
3-8-1 Komaba, Meguro-ku Tokyo 153, Japan
Base sequences of genomes were found to consist of a restricted set of homologous short segments when examining base sequences of several genomes classified into different branches of the phylogenetic tree of life. The homologous segments were longer than the triplet codons encoding amino acids, and were observed in both coding and noncoding regions more frequently than the random expectation level. They are thus likely to be the vestiges of the primordial words arisen in the primeval Earth eons ago.