ABSTRACT

Molecular biologists, like most people, feel little surprise at hearing criticism of others. It is rather generally felt that one of the next major biological problems which molecular biology will, or should, clear up is that of cellular differentiation in higher organisms. In the first place, it should be pointed out that the analogy between theoretical biology and theoretical physics involves a comparison of two bodies of theory which are at very different stages of historical development. Biology is in fact in the process of creating its theories ‘from the elementary units to the complex’, at the same time as it is making such rapid advances in the analysis of the units. The main endeavour seems always to be to deepen the comprehension of ultimate elements, the relation between these elements and complex physical systems such as macromolecular chemistry, solid state physics, etc., being left to specialists who can almost be dismissed as ‘mere engineers’.