Nuclear DNA from old collections of avian study skins reveals the evolutionary history of the Old World suboscines (Aves, Passeriformes)

Abstract

Museum study skins represent an invaluable source of DNA for phylogenetics, phylogeography and population genetics. This becomes evident by comparing the number of study skins of birds housed in museums worldwide (c. 10 million) with the corresponding number of tissue samples (probably fewer than 500 000). While the laboratory techniques used hitherto have primarily allowed PCR‐based studies of mitochondrial genes from museum skins, we present here the first avian phylogeny based on a large number of nuclear sequences. The targeted fragment sizes and the properties of the primers used are important contributory factors to obtain good amplification results. In this study we routinely amplified fragments of c. 350 bp nuclear DNA. This advance in methodology opens up a new avenue for the use of avian museum skins, as nuclear DNA is especially useful when studying ancient patterns of diversification. The phylogenetic hypothesis of the Old World suboscines (Eurylaimides) presented herein strongly supports a monophyletic origin of the pittas (Pittidae). The phylogeny further suggests that pittas could be divided into three major groups, in agreement with the external morphological variation found in this group. The broadbills (Eurylaimidae) as currently defined are, on the other hand, found to be a paraphyletic family, as both Sapayoa aenigma and the asities (Philepittidae) are nested among them. Based on the phylogenetic results we suggest a revised classification of the Old World suboscines (Eurylaimides).