1. Lewontin, R. C. The Genetic Basis of Evolutionary Change (Columbia University Press, New York, 1974).
2. Ewens, W. J. & Feldman, M. W., In Population Genetics and Ecology (eds S. Karlin & E. Nevo) (Academic, New York, 1976).
3. Johnson, G. B. Science 184, 28–37 (1974).
4. Hochachka, P. W. & Somero, G. N. Strategies of Biochemical Adaptation (Saunders, Philadelphia, 1974).
5. Somero, G. N., In Isozymes II (ed. C. L. Markert) 221–234 (Academic, New York, 1975).