ABSTRACT

Beyond continuous dynamic models, the dynamic nature of biological systems can also be captured by discrete dynamic models. Discrete-time models have been popularly applied in biology to model population growth, where the population of a given species at time-step t is modelled as a function of the population in the previous time-steps, {t-1,…}. This chapter focuses on models where the variables are also assumed to have a finite set of possible states. In particular, it focuses on logical models, as captured by Boolean networks, where these states are only two, namely ON and OFF. Transfer functions relate the output or response of a variable to the inputs. Created by British mathematician John Conway in 1970, the “Game of Life” is a classic example of a discrete simulation. Proposed by Steffen Klamt and co-workers, logical interaction hypergraphs were shown to be a useful formalism to model and understand signalling and regulatory networks.