Phylogeny and biogeography of the New World siskins and goldfinches: Rapid, recent diversification in the Central Andes

• Published in: Molecular phylogenetics and evolution Vol. 87; pp. 28 - 45
• Main Authors: Beckman, Elizabeth J., Witt, Christopher C.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.06.2015
• Subjects: Animals; Astragalinus; Bayes Theorem; Biological Evolution; Carduelis; Ecosystem; Finches - classification; Fringillidae; Genes, Mitochondrial; Introns; Likelihood Functions; Models, Genetic; Passeriformes - classification; Phylogeny; Phylogeography; Sequence Analysis, DNA; South America; Spinus; Sporagra; South America; Carduelis; Astragalinus; Sporagra; Fringillidae; Spinus
• ISSN: 1055-7903; 1095-9513
• DOI: 10.1016/j.ympev.2015.03.005

[Display omitted] •New World siskins and goldfinches are a rapid, Pleistocene radiation.•High Central Andean siskin diversity arose in situ over the last ∼0.2million years.•Siskin speciation rate was higher within the Andes than outside the Andes.•Páramo expansion and contraction likely caused accelerated diversification.•Siskins had a higher dispersal rate out of the Andes than into the Andes. Time-calibrated molecular phylogenies can help us to understand the origins of the diverse and unique Andean avifauna. Previous studies have shown that the tempo of diversification differed between the Andes and adjacent lowland regions of South America. Andean taxa were found to have speciated more recently and to have avoided the decelerated diversification that is typical of Neotropical lowland clades. The South American siskins, a Pleistocene finch radiation, may typify this Andean pattern. We investigated the phylogenetic biogeography of all the New World siskins and goldfinches in new detail. To understand the specific role of the Andes in siskin diversification, we asked: (1) Was diversification faster in Andean siskin lineages relative to non-Andean ones? (2) Did siskin lineages move into and out of the Andes at different rates? We found that siskin lineages in the Andes had higher diversification rates and higher outward dispersal rates than siskin lineages outside the Andes. We conclude that páramo expansion and contraction in response to Pleistocene climatic cycles caused accelerated diversification and outward dispersal in Andean siskins. The younger average age of bird species in the Andes compared to lowland South America may be attributable to bursts of recent diversification in siskins and several other vagile, open-habitat clades.