HOW A REACTIVE SYSTEMS APPROACH MAY LEAD TO FULL DYNAMIC MODELS OF MULTICELLULAR ORGANISMS
One-day experiments on living beings will be, to a large extent, substi-tuted by interactive simulations on computers. A decade ago, computer scientist David Harel, winner of the Israel Prize, the ACM Software System Award, the Emet Prize and four honorary degrees, proposed the scientific grand challenge of modelling a full multicellular organism as a reactive system. He suggested the 1000-cell C. elegans nematode as the model organism. In an estimated 10 to 15 years of intensive work, a multidisciplinary team could construct a full model of this organism, or a similar one, in its development and behaviour. The model would be dynamic, interactive and zoomable, allowing changes and probes on the cellular and molecular levels. Such tools would allow cyber-experiments in order to answer questions too complex for laboratory techniques, including comparisons not only within a species, but also with evolutionarily related species with different forms and behaviours. Thus 21st century research in the life sciences and medicine is poised to undergo a major transition, in which computer science will play a central role, similar to the role of mathematics in the physical sciences of the 20th century.