They're far from the scaled reptilian giants that once walked the Earth, but for decades researchers have sought out an evolutionary connection between our winged bird species of today and the dinosaurs that once took flight in prehistoric times. For the past four years, a team of international researchers have fully developed The Avian Phylogenomics Project, in which they have sequenced genomes of nearly all species of the evolutionary branches including a majority of birds known to man. Now that the research is done, the mapping of 48 bird species genomes has evolved into more than two-dozen articles published in the journal Science, as well as a new understanding of how birds may link to their dinosaur ancestors.
While the study is the first of its kind, tracing back the lineages of 48 species of birds to pre-Cambrian ancestors, researchers have long known that birds survived the mass extinction that once exterminated reptilian dinosaurs from the face of the Earth. However, what ornithologists have long wondered is what led to the rapid evolutionary explosion that led a single bird ancestor into over 10,000 unique avian species. Genomic studies of modern-day birds reveals that early speciation occurred rather rapidly, limiting the genetic differences distinguishable at the level of DNA. So, in order to resolve timing and investigate the lineages of modern bird species, the consortium of international researchers involved in the Avian Phylogenomics Projects compared the full genomes of the 48 species, comparing similar base changes that followed patterns across the group of birds.
Lead researcher of the consortium, Guojie Zhang of the National Genebank at BGI in China says "This is the largest whole genomic study across a single vertebrate class to date." In fact, the project involved laboratories from more than 20 countries and over 200 researchers worldwide.
Yielding new insights into the evolutionary origins of today's modern species of birds, the study dove into genetic makeup that drives behavior and how their phylogenetic clades arose. Though, each article published in the journal Science specifically deciphers the mysteries between closely related modern-day species. The researchers hope that the data derived from the study may one day lead to an even more detailed evolutionary tree for bird species, giving ornithologists a better understanding of the vastly diverse traits and dimorphisms exhibited in birds.
"In the past, people have been using one, two -up to 10 to 20 genes-to try to infer species relationships over the last 100 million years or so" another lead researchers of the project, Duke University neurobiologist, Erich Jarvis says. "Our theory has been, if you take the whole genome, you would have a more accurate species tree than just one or two genes alone."
