A method of analyzing an evolution of a biological system comprising the steps of determining a series of variables upon which a state of the biological system depends, mapping the variables to an n-dimensional space, and wherein the evolution of the biological system is monitored utilising a trajectory formed from sets of the variables which define the states of the biological system at different times, thereby using time as a parameter in the n-dimensional space in a manner such that every point on the trajectory corresponds to at least one value of time.