PopSci – A sticky piece of DNA is rewriting the story of avian evolution–and shaking up the family tree: “An enormous asteroid crashed into the Earth about 65 million years ago. While terrestrial dinosaurs like the famed Tyrannosaurus rex were wiped out, many avian animals really began to flourish. Considering that there are more than 10,000 species of birds on Earth, flourish may even be an understatement. Keeping birds organized in a neat family tree is a bit of a Herculean task, since there are so many species and their evolution has been a little unclear. However, some advances in genomic sequencing and analysis are beginning to create a more lucid picture of how the planet’s living dinosaurs evolved. In two studies published April 1 in the journals Proceedings of the National Academy of Sciences (PNAS) and Nature, scientists reveal that a genetic event about 65 million years ago has misled them about the true history of avian evolution. A section of one chromosome hasn’t mixed together with nearby DNA as it should have. This section is only tiny fraction of the bird genome, but was enough to make it difficult for scientists to build a more detailed bird family tree…In future studies, similar computer models could help reconstruct evolutionary trees for a variety of other animals. The team is hoping to continue their efforts to build a more complete picture of bird evolution. Biologists are also continuing to sequence the genomes of other bird species in an effort to expand their family tree even more. The work is part of the international Bird 10,000 Genomes (B10K) Project, a multi-institutional effort with the goal of generating draft genome sequences for about 10,500 living bird species…”