Showing how all organisms on Earth are related to each other has been a major goal of biologists since the time of Darwin. The "Tree of Life" illustration is critical to understanding when and how key traitsâ€” like the ability to cause or transmit harmful diseasesâ€”evolved. But progress has been slow, because the methods available for analyzing genes are costly, labor intensive and error-prone.
Now researchers at the University of Colorado School of Medicine have shown how assembly of the Tree of Life can be greatly sped up. Writing in the "Proceedings of the National Academy of Sciences of the USA," postdoctoral fellow Chris Todd Hittinger and Professor Mark Johnston and their collaborators at Vanderbilt University report their use of new and very high throughput DNA sequencing technologies to identify hundreds of genes from 10 different species of mosquitoes. By comparing these genes they were able to determine the relationships of these mosquitoes, which are responsible for spreading malaria, yellow fever, and dengue hemorrhagic fever. The researchers describe how application of their approach will bring a complete Tree of Life on our planet within reach.
"There are thousands of mosquito species and more than 2 million species on our planet. Determining how they are all related is a massive undertaking, and we have provided a roadmap for how to achieve the dramatic cost and labor reductions that will be required to reach this important goal," said Mark Johnston, chairman of the department of biochemistry and molecular genetics at the University of Colorado School of Medicine.
"We developed an experimental and computational approach that promises to greatly speed the process. We employed state-of-the-art, next-generation DNA sequencing technology to sample hundreds of genes from 10 mosquito species. This tremendous quantity of data allowed us to accurately determine their evolutionary relationships with unprecedented efficiency and at such a low cost that it will soon bring Darwin's dream of the Tree of Life within reach" added Hittinger.