Extensive host-switching of avian feather lice following the Cretaceous-Paleogene mass extinction event

Robert S De Moya,Julie M Allen,Michel P Valim,Kimberly K O Walden,Stephen L Cameron,Kevin P Johnson,Vincent S Smith,Ricardo L Palma,Terry D Galloway,Jason D Weckstein,Andrew D Sweet

doi:10.1038/s42003-019-0689-7

Abstract

Nearly all lineages of birds host parasitic feather lice. Based on recent phylogenomic studies, the three major lineages of modern birds diverged from each other before the Cretaceous-Paleogene (K-Pg) mass extinction event. In contrast, studies of the phylogeny of feather lice on birds, indicate that these parasites diversified largely after this event. However, these studies were unable to reconstruct the ancestral avian host lineage for feather lice. Here we use genome sequences of a broad diversity of lice to reconstruct a phylogeny based on 1,075 genes. By comparing this louse evolutionary tree to the avian host tree, we show that feather lice began diversifying on the common ancestor of waterfowl and landfowl, then radiated onto other avian lineages by extensive host-switching. Dating analyses and cophylogenetic comparisons revealed that two of three lineages of birds that diverged before the K-Pg boundary acquired their feather lice after this event via host-switching.

Highlights

Most lineages of birds host parasitic feather lice
We compared the reconstructed evolutionary tree of feather lice with two major avian host phylogenies that were derived from phylogenomic data sets[1,2]
We found that the feather lice of these birds tended to be closely related

Summary

Introduction

Most lineages of birds host parasitic feather lice. Based on recent phylogenomic studies, the three major lineages of modern birds diverged from each other before the CretaceousPaleogene (K-Pg) mass extinction event. We use genome sequences of a broad diversity of lice to reconstruct a phylogeny based on 1,075 genes By comparing this louse evolutionary tree to the avian host tree, we show that feather lice began diversifying on the common ancestor of waterfowl and landfowl, radiated onto other avian lineages by extensive host-switching. The Galloanserae includes waterfowl (Anseriformes) and landfowl (Galliformes), which diverged from the remaining avian lineages (Neoaves) between 71 and 90 Mya[1,2] All three of these groups of birds host ectoparasitic feather lice[3], but it is currently unclear on which avian ancestor these parasites originated. We compared the reconstructed evolutionary tree of feather lice with two major avian host phylogenies that were derived from phylogenomic data sets[1,2] These two avian phylogenies are similar in many respects, including the same topological relationships among Palaeognathae, Galloanserae, and Neoaves. Our cophylogenetic analyses incorporate this uncertainty in the avian tree

Methods

Results

Conclusion