This week as part of our series on our most cited papers of 2014 and 2015, we highlight New insights into New World biogeography: An integrated view from the phylogeny of blackbirds, cardinals, sparrows, tanagers, warblers, and allies, a paper by F.K. Barker et al. from the April 2015 issue of The Auk: Ornithological Advances. With coverage of nearly 8% of all 10,000 avian species, this paper presents the largest, most complete, entirely molecular data-based phylogeny for any group of organisms studied to date. The phylogeny covers 791 of the approximately 832 species in Emberizoidea, a diverse group of New World songbirds including blackbirds, cardinals, sparrows, tanagers, and wood warblers.
With the new and improved family tree generated from a team of extraordinary evolutionary biologists, F. Keith Barker of the University of Minnesota and his colleagues were able to derive many new insights about the biogeography of these birds. For example, the ancestors of all of these New World birds likely arrived in North America via an ice-age land bridge from Eurasia, after which they diversified and expanded into South America, the Caribbean, and even back into Eurasia. Other species kept moving back and forth between North and South America, and did so with increasing frequency after the closing of the Isthmus of Panama.
Contrary to previous theories, Barker et al. also concluded that the ancestral ranges for modern-day long-distance migrants in this group were probably in North America, meaning that prior to the evolution of the annual migration they resided in regions that now include only their breeding ranges.
Read the full paper at http://www.aoucospubs.org/doi/full/10.1642/AUK-14-110.1.