Scientists at the University of Oregon have determined the fine-scale genetic structure of the first animal to show an evolutionary response to rapid climate change.
They used a high-throughput sequencing technique called Restriction-site Associated DNA (RAD) tagging to make the discovery.
Their results, which focus on the pitcher plant mosquito, Wyeomyia smithii, are published this week in the journal Proceedings of the National Academy of Sciences (PNAS).
RAD tagging is an effective and straightforward way of barcoding sections of genomic material, much as grocery items are coded at the local supermarket, say the scientists.
"This project demonstrates the power of genomics technologies, which can provide new knowledge about the vast array of Earth's species," says Sam Scheiner, program director in the National Science Foundation (NSF)'s Division of Environmental Biology, which funded the research.
"Although this small mosquito has become the poster child for genetic response to climate change," says William Bradshaw, one of the paper's co-authors, "its evolution during post-glacial invasion of North America has been a question."
Using the RAD-Tag approach, the scientists have demonstrated that post-glacial populations of Wyeomyia smithii originated from a southern Appalachian Mountain refugium after recession of the Laurentide Ice Sheet some 22,000 to 19,000 years ago.
Range expansion into the previously glaciated north proceeded in a sequential, ordered wave rather than by a "hit-or-miss" hopscotch process, the biologists found.
With this detailed information, they will be able to determine the genetic mechanism underlying photoperiod response to rapid climate change--responsible for the correct timing of dormancy, migration, development and reproduction in temperate organisms.
The knowledge will act as a template for research on blood-feeding in mosquito vectors of dengue
|Contact: Cheryl Dybas|
National Science Foundation