Nils A. Barricelli
The first theoretical biologist who came to the Institute was Nils Barricelli, who was invited by John von Neumann in 1953 and stayed here for two terms. Using the computer that von Neumann had built at the Institute, Barricelli simulated the evolution of populations of artificial organisms. Each organism was represented by a genome consisting of a string of numbers. Random mutations and sexual exchange of genes caused populations to evolve. Barricelli observed the phenomena of speciation, parasitism, and predation arising spontaneously in his computer runs. He also observed punctuated equilibrium, the tendency of dominant species to remain static for many generations and then suddenly give way to new dominant species of a different character. He was a pioneer of the new science of artificial life, forty years before it became fashionable. With astonishing ingenuity he was able to simulate sophisticated evolutionary processes on a machine with a total memory of four kilobytes.
Freeman Dyson, “Biology at the Institute for Advanced Study”