In recent years, scientists discovered that the inside of the cell is a surprisingly noisy place, overturning a long-held assumption that its inner workings are regular and predictable. Molecules within the cell move around and interact randomly, meaning that any subsequent biochemical reactions, such as the production of RNA and protein — needed for nearly all cell activity — also have some element of randomness. How can a cell carry out its jobs — eating, dividing, differentiating — if the machinery that drives those mechanisms is a molecular commotion? The development of an embryo, for example, looks like a well-programmed process, orchestrated by predictable waves of gene activity to produce a specific pattern of tissues. How could it possibly emerge amid this pervasive noise?
Genetically identical bacteria produce varying amounts of green fluorescent protein, illustrating the random nature of gene activity. Scott Cookson and Jeff Hasty