A. Distribution of protein pairs across domain architecture similarity classes. All ortholog and cross-species paralog pairs in each species were divided into four qualitatively distinct classes (See Results), that are plotted as averaged fractions over all species comparisons. B. Distribution of protein pairs across domain swapping event categories. Protein pairs with partially preserved domain architecture (classes SameContentNotAligned and DiffContent in A) were further characterised in terms of inferred domain swapping events according to the five categories defined in Figure 1. The chart shows averages over all species comparisons. Error bars indicate the standard deviation across species.