Building the avian tree of life using a large-scale, sparse supermatrix

Area of Science:

• Ornithology
• Evolutionary Biology
• Genomics

Background:

• Birds represent the most diverse tetrapod class, with approximately 10,000 extant species.
• A significant increase in available molecular data for avian species has occurred.
• Most avian taxa originated during a relatively short evolutionary period.

Purpose of the Study:

• To assemble available sequence data from birds to estimate a large-scale avian phylogeny.
• To infer an unconstrained evolutionary tree of life for birds.
• To assess the sufficiency of current molecular data for robust phylogenetic inference.

Main Methods:

• Assembled sequence data from 6,714 bird species.
• Performed an unconstrained maximum likelihood analysis.
• Utilized a supermatrix comprising 22 nuclear and seven mitochondrial loci.

Main Results:

• Inferred a large-scale avian phylogeny with a backbone consistent with previous detailed analyses.
• Confirmed monophyly for all avian orders with generally high support.
• Identified areas of low support within families and genera, particularly in oscine passerines, suggesting taxonomic circumscription issues.

Conclusions:

• The current volume of sequence data is adequate for robust avian tree of life estimation using modern methods.
• The resulting unconstrained phylogeny with data-driven branch lengths will aid comparative analyses and taxonomic revisions.
• This phylogeny can guide future data collection efforts for underrepresented taxa.