The team, working with the Vertebrate Genomes Project, sequenced the genomes of 51 vertebrate species, prioritizing those that are useful models for understanding human evolution. By comparing the complete genomes of these species, researchers can start to identify when and where DNA sequences diverged and the implications of those differences for humans. Vertebrate genomes are billions of characters long, too long for any gene sequencing technology to read in one complete pass. To test their technology, researchers mapped the genome of the zebra finch, a songbird that had already been sequenced to study brain development. The team will continue working with the Vertebrate Genomes Project to sequence the genomes of at least one species across all 275 vertebrate orders.