The Workshop on "Evolutionary Tinkering in Gene Expression" which was held at the end of August 1988. was planned to celebrate 20 successful Advanced Study Institutes (A. S. I.) in Molecular and Cell Biology. The first Institute was held in 1966 on the Island of Spetsai. after a N. A. T. O. suggestion and was entirely financed by N. A. T. O. The success was immediately so great that the Institute grew very rapidly and in the following years. N. A. T. O .- E. M. B. O. (since 1972) and F. E. B. S. (since 1981) co-sponsored it. Since the start of the AS . the U. S. National Science Foundation...