Figure 1.

Collective phenotypes drive acid-mediated invasion. Spatial and temporal evolution of two distinct initial spatial configurations of identical numbers of cellular phenotypes leads to differential outcomes due to context-dependent selection. A low glycolysis phenotype (blue) and a high glycolysis phenotype (purple) compete for resources according to the rules outlined in section S1. Top row: a mixed configuration leads to no evolution. Acid-mediated invasion does not occur because the volumetric concentration of acid produced by aggressive cells is not enough to cause invasion when highly glycolytic cells are seeded far apart. Bottom row: In contrast, artificially placing the aggressive high glycolysis phenotypes on the rim leads to invasion from increased volumetric acid via a group-effect. Note: this figure has shorter timescales than subsequent figures, as it is seeded with pre-existing heterogeneity.