ORIGINAL ARTICLE doi:10.1111/evo.12695 Breeding system evolution influenced the geographic expansion and diversification of the core Corvoidea (Aves: Passeriformes) Petter Z. Marki,1,2,3,∗ Pierre-Henri Fabre,1,4 Knud A. Jønsson,1,5,6 Carsten Rahbek,1,5 Jon Fjeldsa,˚ 1 and Jonathan D. Kennedy1,∗ 1Center for Macroecology, Evolution and Climate, Natural History Museum of Denmark, University of Copenhagen, Universitetsparken 15, DK-2100 Copenhagen, Denmark 2Department of Environmental and Health Studies, Telemark University College, Hallvard Eikas Plass, N-3800 Bø, Norway 3E-mail:
[email protected] 4Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138 5Department of Life Sciences, Imperial College London, Silwood Park Campus, Ascot, West Berkshire, SL5 7PY, United Kingdom 6Department of Life Sciences, Natural History Museum, Cromwell Road, London SW7 5BD, United Kingdom Received July 9, 2014 Accepted May 20, 2015 Birds vary greatly in their life-history strategies, including their breeding systems, which range from brood parasitism to a system with multiple nonbreeding helpers at the nest. By far the most common arrangement, however, is where both parents participate in raising the young. The traits associated with parental care have been suggested to affect dispersal propensity and lineage diversification, but to date tests of this potential relationship at broad temporal and spatial scales have been limited. Here, using data from a globally distributed group of corvoid birds in concordance with state-dependent speciation and extinction models, we suggest that pair breeding is associated with elevated speciation rates. Estimates of transition between breeding systems imply that cooperative lineages frequently evolve biparental care, whereas pair breeders rarely become cooperative.