A phylogenomic study of birds reveals their evolutionary history

Abstract

Deep avian evolutionary relationships have been difficult to resolve as a result of a putative explosive radiation. Our study examined ~32 kilobases of aligned nuclear DNA sequences from 19 independent loci for 169 species, representing all major extant groups, and recovered a robust phylogeny from a genome-wide signal supported by multiple analytical methods. We documented well-supported, previously unrecognized interordinal relationships (such as a sister relationship between passerines and parrots) and corroborated previously contentious groupings (such as flamingos and grebes). Our conclusions challenge current classifications and alter our understanding of trait evolution; for example, some diurnal birds evolved from nocturnal ancestors. Our results provide a valuable resource for phylogenetic and comparative studies in birds. Although well studied, the evolutionaryrelationships among major avian groupsare contentious (1–6). Recovering deep evolutionary relationships in birds is difficult, probably reflecting a rapid divergence early in their evolutionary history (1–3, 7, 8) that has resulted in many distinctive, morphologically co-hesive groups (e.g., owls, parrots, and doves) wit