An international team of scientists have characterized the genome of 363 species of birds representing 92.4% of avian families. 267 of these species were newly released sequences as part of the Bird 10,000 Genomes (B10K) Project. The goal of this project is to find both similarities as well as unique genome variations among lineages of birds that might contribute to their amazing biodiversity. The study also confirmed that the common ancestor of birds lost quite a few genes as 498 genes were missing from all of the species included in the study.
One finding that I found particularly interesting was that eagles and birds of prey (Accipitriformes), cormorants (Phalacrocoracidae), and songbirds (Passeriformes) are either missing or have mutations in the gene cornulin, which encodes a protein in the lining of the esophagus and oral cavity of humans and chickens. They speculate that the loss of this particular protein may have helped songbirds develop their diverse vocalizations.
I am sure there will be many more interesting discoveries as researchers further explore the diversity of avian genomes.
S Feng, J Stiller, Y Deng, et al. Dense sampling of bird diversity increases power of comparative genomics. Nature 587, 252–257 (2020). https://doi.org/10.1038/s41586-020-2873-9