| Popis: |
Striking asymmetries of species richness characterise the tree of life, and understanding their causes is a major research agenda in evolutionary biology. Genome duplications have been proposed as one mechanism by which lineages acquire greater potential for rapid genetic evolution following the relaxation of pleiotropic constraints. This enhanced evolvability might facilitate faster rates of morphological change and speciation. We provide a comprehensive test of the empirical association between polyploidy – a marker of genome duplication – and species richness in 356 pairs of extant polyploid and non-polyploid sister clades. Comparing sister clades controls for divergence time and many ecological and morphological properties of groups. Clades with inferred basal genome duplications have significantly higher species diversity than their sister clades, both for the whole dataset, major groups of animals and plants within it and at the genus and family levels. Genome duplications therefore offer one possible, widespread cause of heterogeneities in species richness. |
