Parallel Evolution of Bower-Building Behavior in Two Groups of Bowerbirds Suggested by Phylogenomics

AbstractThe bowerbirds in New Guinea and Australia include species that build the largest and perhaps most elaborately decorated constructions outside of humans. The males use these courtship bowers, along with their displays, to attract females. In these species, the mating system is polygynous and the females alone incubate and feed the nestlings. The bowerbirds also include 10 species of the socially monogamous catbirds in which the male participates in most aspects of raising the young. How the bower-building behavior evolved has remained poorly understood, as no comprehensive phylogeny exists for the family. It has been assumed that the monogamous catbird clade is sister to all polygynous species. We here test this hypothesis using a newly developed pipeline for obtaining homologous alignments of thousands of exonic and intronic regions from genomic data to build a phylogeny. Our well-supported species tree shows that the polygynous, bower-building species are not monophyletic. The result suggests either that bower-building behavior is an ancestral condition in the family that was secondarily lost in the catbirds, or that it has arisen in parallel in two lineages of bowerbirds. We favor the latter hypothesis based on an ancestral character reconstruction showing that polygyny but not bower-building is ancestral in bowerbirds, and on the observation thatScenopoeetes dentirostris, the sister species to one of the bower-building clades, does not build a proper bower but con...
Source: Systematic Biology - Category: Biology Source Type: research