eLife assessment
This fundamental study evaluates the evolutionary significance of variations in the accuracy of the intron-splicing process across vertebrates and insects. Using a powerful combination of comparative and population genomics approaches, the authors present convincing evidence that higher rates of alternative splicing tend to be observed in species with lower effective population size, a key prediction of the drift-barrier hypothesis. The analysis is carefully conducted and has broad implications beyond the studied species. As such, it will strongly appeal to anyone interested in the evolution of genome architecture and the optimisation of genetic systems.