1. Darwinian, Neo-Darwinian Evolution, Proc. sixth Berkeley Symp., 5, (edit. by Le Cam, L. M., Neyman, J., and Scott, E. L.) (University of California Press, Berkeley and Los Angeles, 1972).
2. Smith, E. L., in The Enzymes (edit. by Boyer, P. D.), 1, 267–314 (Academic New York, 1970).
3. Kimura, M., Nature, 217, 624–626 (1968).
4. King, J. L., and Jukes, T. H., Science, 164, 788–798 (1969).
5. Markussen, J., and Volund, A., Int. J. Peptide Protein Res., 6, 79–86 (1974).