In the last decade, the new theory of metabolic ecology has derived general predictions for a wide range of ecological patterns from fundamental physical and biochemical principles. Predictions for tree growth, mortality and size distributions are particularly significant in light of their potential to help explain globally important carbon stores and fluxes of tropical forests. In a forthcoming pair of papers in Ecology Letters, Muller-Landau and collaborators associated with the Center for Tropical Science test these predictions using large datasets from tropical forests around the world. Observed patterns of tree growth, mortality and abundance deviate substantially from the predictions of metabolic ecology theory, especially for large trees. Variation within and among forests is more consistent with alternative models presented by Muller-Landau and colleagues, models that can incorporate some of the complex variation in tree shapes, growing conditions, and mortality threats within and among diverse tropical forests.