This model is from the article: Cooperation and Competition in the Evolution of ATP-Producing Pathways Thomas Pfeiffer, Stefan Schuster, Sebastian Bonhoeffer Science 2001 Apr; Volume:292 (Issue:5516); Page info:504-7 11283355 , Abstract: Heterotrophic organisms generally face a trade-off between rate and yield of adenosine triphosphate (ATP) production. This trade-off may result in an evolutionary dilemma, because cells with a higher rate but lower yield of ATP production may gain a selective advantage when competing for shared energy resources. Using an analysis of model simulations and biochemical observations, we show that ATP production with a low rate and high yield can be viewed as a form of cooperative resource use and may evolve in spatially structured environments. Furthermore, we argue that the high ATP yield of respiration may have facilitated the evolutionary transition from unicellular to undifferentiated multicellular organisms. Note: This model reproduces the competition and invasion described in Supplemental Figure 2.