Cooperation and competition in the evolution of ATP-producing pathways

Heterotrophic organisms generally face a trade-off between rate and yield o f adenosine triphosphate (ATP) production. This trade-off may result in an evolutionary dilemma, because cells with a higher rate but lower yield of A TP production may gain a selective advantage when competing for shared ener gy resources. Using an analysis of model simulations and biochemical observ ations, we show that ATP production with a low rate and high yield can be v iewed as a form of cooperative resource use and may evolve in spatially str uctured environments. Furthermore, we argue that the high ATP yield of resp iration may have facilitated the evolutionary transition from unicellular t o undifferentiated multicellular organisms.