Putting the systems back into systems biology

Abstract

In recent years the term "systems biology" has become widespread in the biological literature, but most of the papers in which these words appear have surprisingly little to do with older notions of biological systems: they often seem to imply little more than reductionist biology applied on a large scale, with a little attention to interactions between some of the components, but with minimal attention to the kinetic properties of enzymes, which supplied much of the reductionist foundation of biochemistry. A systemic approach to biology ought to put the emphasis on the entire system; insofar as it is concerned with components at all, it is to explain their roles in meeting the needs of the system as a whole. Genuinely systemic thinking allows us to understand how biochemical systems are regulated, and why clumsy attempts to manipulate them for biotechnological purposes may fail. At a more abstract level, it is necessary for understanding the nature of life, because as long as an organism is treated as no more than a collection of components, one cannot ask the right questions, and certainly cannot answer them.