Upon first glance, which of the below diagrams1 makes the most
sense to you? As it happens, both diagrams describe the same
generic biological process. They are drawn from a report
concerning the study of the changing levels of the kinase, R,
over time. S, the “signal”, is the level of mRNA from which R is
transcribed. As well as being the response, R is involved in a
positive feedback loop. R activates the protein E by
phosphorylation and EP in turn enhances the rate of synthesis of
R. When this report including these two figures was shown to (a
small sample of) biologists and to (an equally small sample of)
mathematicians, mathematicians gravitated towards the first
picture and were able to quickly and easily understand how the
time evolution of R could be described using the accompanying
equations. They baulked at the second diagram, describing it as
“confusing” – to the bemusement of biologists who are familiar
with diagrams involving many more interacting molecules. Those
with a background in biology, on