Fig. 2: Trends in the ecometric anomalies (see Supplementary Fig. 1d) of eastern African communities of large herbivores.

Anomalies are shown with respect to estimations of communities’ mean woody cover values from herbivore body mass (a), hypsodonty (b), and longitudinal loph count (c). Maximum-likelihood estimations of woody cover were made for each community using an ecometric model of all communities together through time. Each violin plot depicts the distribution of n = 1000 independent samples, where each sample is the mean ecometric anomaly of a random subset of communities occurring within the plot’s time bin (x axis). Each box plot depicts its distribution’s median (center) and interquartile range (bounds of box), plus 1.5 * the interquartile range above and below the box (whiskers). Dotted lines indicate a mean anomaly of zero. Blue plots represent distributions whose 95% confidence intervals contain zero, while orange plots represent those whose confidence intervals do not. The vertical gray line represents the point at which ecometric anomalies shifted significantly after a long period of consistency. Time bins on the x axis are based on the cutoff points of the time intervals depicted in Fig. 1. 3.15 Ma is the midpoint of 3.3–3 Ma, 1.8 Ma is the midpoint of 1.9–1.7 Ma, and the final time bin represents the present. Source data are provided as a Source Data file.