August 17, 2012
Scientists Sequence Genome Of Darwin’s Finch
Lee Rannals for redOrbit.com — Your Universe Online
The finch, which was first described by Charles Darwin, is the first of the BGI-Genome 10K collaboration to be made available through the UCSC Genome Browser.
"The scientific advancement," Erich Jarvis said in a press release, "is that it will allow us to investigate the genomes of a group of closely related species with a significant amount of diversity on an island population, allowing us to potentially better understand the genetics of trait evolution."
Jarvis, a Duke University associate professor who studies the neurobiology of vocal learning in songbirds, said it is symbolic because it was the diversity of phenotypes in these finches that contributed to Darwin's theory of evolution.
This species of finch are endemic to the subtropical or tropical dry forests and scrublands of the Galapagos Islands. This species evolves rapidly in response to environmental changes.
"These finches are of great historical significance, but when Darwin first studied these birds, he was unlikely to have envisioned how this species would become a perfect model to study evolution in action," BGI's associate director of research, Goujie Zhang, said in a press release. "Having the reference genome of this species has opened the door for carrying out studies that can look at real-time evolutionary changes on a genomic level of all of these enigmatic species."
Jarvis said this new genome will help scientists understand the evolution of vocal learning.
"The availability of the Geospiza fortis will allow us to validate findings so far only found in the zebra finch genome," he said in the release.
He said these include genes with positively selected mutations involved with the vocal learning train in finches and also with behavior necessary for spoken language in humans.
The medium ground finch has several song types, whereas the zebra finch "is a more stereotypes vocal learning species," Jarvis said.
Jarvis said the recording of the finch's songs over the last 40 years reveal dialectic patterns that can now be linked to the genome by sequencing the genomes of additional individuals from living and past populations.
"Like human spoken language, Geospiza song dialects are stable over many generations, but can change with emigration," Jarvis said in the release. "Having the well assembled draft reference genome of one individual will now allow scientists to determine if this cultural evolution is partly affected by genetics or is all pure cultural transmission."
Zhang said the genomic data also serves as the base for population studies that will help in conservation of the finches.
He said medium ground finch genomes were sequenced from an individual female, producing a high-quality draft using 115X coverage data from the Illumina HiSeq sequencing system.
"The genome sequence empowerment of Darwin's finches will initiate the solving of evolutionary riddles that have puzzled biologists for a century," Genome 10K co-founder Stephen O'Brien said in a press release.
Oliver Ryder, director of genomics at the San Diego Zoo, said the new genome's availability will create stewardship of earth's biodiversity.