Fig. 4: Changes in composition that occur in three-species communities are well predicted by those that occur in two-species communities.

A An example predicting the composition of one community at ecological and evolutionary timescales. The trio and the pairwise compositions of the three-species community Ea-Pa-Pv at generation ~70 and ~400. Each triangle is a simplex denoting the fractions of the three species, where each node is a specific species. The black stars on the edges denote the mean fractions in pairwise competition, the orange dots are the compositions of each of the trio replicates. The green cross is the predicted trio composition by pairs at the same generation and the red square, purple triangle, and black dot are predictions made by pairs at generation ~70, species mean carrying capacities at the same generation, and the best-uninformed guess (which means that the species fractions would all be 1/3) respectively. B The accuracy of prediction as \(1-\frac{\Delta ({\rm{prediction}},{\rm{observation}})}{\sqrt{{\rm{n}}}}\), where\(\,\Delta\, ({\rm{Prediction}},\,{\rm{Observation}})\) is the Euclidean distance between the prediction and the observation and \(\sqrt{n}\) is the largest possible distance between two communities with the same n species (here n = 3). Colored markers indicate the mean prediction accuracies of the predictions exemplified in (A), error bars indicate standard errors of 23 trios, and connecting lines help to visualize but do not have a biological meaning. Only trios composed of pairs whose evolutionary trajectories were measured were included in the analysis. Source data are provided as a Source Data file.