The Pareto front connects the archetypes – systems which are optimal for only one of the two tasks.

<p>The effectiveness (a) and economy (b) contours radiate outwards from the archetypes, which have their dynamics described in adjacent boxes (). (c) The Pareto front is the set of points where the contours of the two performance functions are externally tangent. The plot shows the Pareto front when input changes are rare, that is . The Pareto front is a curve that connects the two archetypes. In the inset the Pareto front in performance space- note that axes are the effectiveness and economy, not the biochemical parameters as in parameter space of (a)–(c). The archetypes have the maximal performance in their respective tasks. An analytical solution shows the front is a parabola in performance space (see <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1003163#s4" target="_blank">Methods</a>). (d) the overlay of the contours of (a) and (b), and the resulting Pareto front (See <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1003163#pcbi-1003163-g006" target="_blank">Fig. 6</a> for further details).