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Researchers Publish First Draft of Tree of Life That Will Map All Known Species

The most comprehensive draft was published in PNAS the week of Sept. 14.
Photo credit: Open Tree of Life

Most Comprehensive Draft to Date Combines Previously Published Branches to Form One Tree

September 21, 2015
Emily Grebenstein: [email protected], 202-994-3087
Kurie Fitzgerald: [email protected], 202-994-6461
WASHINGTON (Sept. 21, 2015)—A first draft of the “tree of life” for the roughly 2.3 million named species of animals, plants, fungi and microbes -- from platypuses to puffballs -- has been released.
The tree is a collaborative effort among 11 institutions, including researchers from the George Washington University, and depicts the relationships among living things as they diverged from one another over time, tracing back to the beginning of life on Earth more than 3.5 billion years ago.
Tens of thousands of smaller trees have been published over the years for select branches of the tree of life -- some containing upwards of 100,000 species -- but this is the first time those results have been combined into a single tree that encompasses all of life. The end result is a digital resource that is freely available online for anyone to use or edit, much like a “Wikipedia” for evolutionary trees. 
“It turns out that evolutionary history is really essential for understanding all kinds of key puzzles in biology,” said Keith Crandall, a co-author of the draft and director of the GW Computational Biology Institute. “It provides insights into disease transmission patterns and has been used to interpret and predict impacts of climate change on plants, animals and microbes.”
The release is described in the Proceedings of the National Academy of Sciences the week of Sept. 14. The current version of the tree, along with the underlying data and source code, is available to browse and download at
This initial comprehensive draft is based on nearly 500 smaller trees from previously published studies, but the vast majority of evolutionary trees are published as PDFs and other image files that are impossible to enter into a database or merge with other trees. 
As a result, the relationships depicted in some parts of the tree, such as the branches representing the pea and sunflower families, don’t always agree with expert opinion. 
Other parts of the tree, particularly insects and microbes, remain elusive. 
“Putting all the species of the planet together in a single evolutionary history is really the centerpiece of biodiversity science,” Dr. Crandall said. “Now, we have a framework to take advantage of previously splintered knowledge joined through the OpenTree project into a single Tree of Life.”
This research was supported by a three-year, $5.76 million grant from the U.S. National Science Foundation (1208809) and was led by Karen Cranston, bioinformatics project manager at Duke University. 
Other study co-authors include Christopher Owen of GW; Cody Hinchliff and Stephen Smith of the University of Michigan; James Allman of Interrobang Corporation; Gordon Burleigh, Ruchi Chaudhary, Jiabin Deng of the University of Florida; Lyndon Coghill, Peter Midford and Richard Ree of the Field Museum of Natural History; Bryan Drew of the University of Nebraska-Kearney; Romina Gazis and David Hibbett of Clark University; Karl Gude of Michigan State University; Laura Katz and H. Dail Laughinghouse IV of Smith College; Emily Jane McTavish of the University of Kansas; Jonathan Rees of the National Evolutionary Synthesis Center; and Tiffani Williams at Texas A&M University.
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