Reweaving the tapestry: A supertree of birds

Abstract

Our knowledge of the avian tree of life remains uncertain, particularly at deeper levels due to the rapid diversification early in their evolutionary history. They are the most abundant land vertebrate on the planet and have been of great historical interest to systematists. Birds are also economically and ecologically important and as a result are intensively studied, yet despite their importance and interest to humans around 13% of taxa currently on the endangered species list perhaps as a result of human activity. Despite all this no comprehensive phylogeny that includes both extinct and extant species currently exists. Here we present a species-level supertree, constructed using the Matrix Representation with Parsimony method, of Aves containing approximately two thirds of all species from nearly 1000 source phylogenies with a broad taxonomic coverage. The source data for the tree were collected and processed according to a strict protocol to ensure robust and accurate data handling. The resulting tree topology is largely consistent with molecular hypotheses of avian phylogeny. We identify areas that are in broad agreement with current views on avian systematics and also those that require further work. We also highlight the need for leaf-based support measures to enable the identification of rogue taxa in supertrees. This is a first attempt at a supertree of both extinct and extant birds, it is not intended to be utilised in an overhaul of avian systematics or as a basis for taxonomic re-classification but provides a strong basis on which to base further studies on macroevolution, conservation, biodiversity, comparative biology and character evolution, in particular the inclusion of fossils will allow the study of bird evolution and diversification throughout deep time.