A phylogenomic tree of wood-warblers (Aves: Parulidae): Dealing with good, bad, and ugly samples

Abstract

The New World warblers (Parulidae) are a model group for ecological and evolutionary analyses. However, current phylogenetic relationships across this family are based upon few loci. Here we use ultraconserved elements (UCEs) to estimate a rigorous species-level phylogeny for the family. As is true for many groups, high-quality tissues were unavailable for some taxa. Thus, we explored methods for incorporating sequences derived from historical (toe pad) samples to expand the phylogenetic datasets. We recovered an average of 4,186 UCE loci and mitochondrial bycatch data (supplemented with published mitochondrial data) from 96% of all currently recognized species. We found that the UCE phylogeny built with alignments with less than 70% of gaps and ambiguities recovered the most robust phylogenetic relationships for this family, representing 101 species. Using this phylogeny as a topological backbone and adding ten fair quality “bad” samples effectively generated an overall well supported phylogeny, representing 108 species (∼90% of all species). Based on this tree, we then added in seven poor quality “ugly” samples and six of those were placed within their expected genera. We also explored the phylogenetic positions of the likely extinct Leucopeza semperi and the endangered Catharopeza bishopi where limited data was obtained. Overall, taxonomic placements in our UCE trees largely correspond to previously published studies with the recovery of all currently recognized genera as monophyletic except for Basileuterus which was rendered paraphyletic by B. lachrymosus. Our study provides insights in understanding the phylogenetic relationships of a model Passeriformes family and outlines effective practices for managing sparse genomic data sourced from historical museum specimens. Variable topological arrangements across datasets and analyses reflect the evolutionary complexity of this group and provide future topics for in-depth studies.