First comprehensive Tree of Life illustrates relationships between 2.3 million species

In what’s being called the “first real attempt to connect the dots and put it all together,” this open-access project aims to link “all biodiversity through a shared evolutionary history.”

How did life on Earth go from simple single-celled organisms to the incredibly complex human body? A number of attempts have been made to build an evolutionary ‘tree of life’ that connects the organisms on the planet, but until now, there has been no single comprehensive tree of life assembled. However, thanks to a multi-year grant from the U.S National Science Foundation, a collaborative effort from researchers at 11 institutions has produced an initial draft of this audacious project, which includes some 2.3 million species, called the Open Tree of Life.

The Open Tree of Life builds on the work of previous researchers, who have created some tens of thousands of smaller ‘trees’ for individual branches, and the result is a massive digital resource that aims to connect the threads of millions of species on Earth. The project is open-access and editable, which means that not only can anyone view the data, but can also edit or add to it, somewhat like a Wikipedia for evolutionary relationships.

“Evolutionary trees, branching diagrams that often look like a cross between a candelabra and a subway map, aren’t just for figuring out whether aardvarks are more closely related to moles or manatees, or pinpointing a slime mold’s closest cousins. Understanding how the millions of species on Earth are related to one another helps scientists discover new drugs, increase crop and livestock yields, and trace the origins and spread of infectious diseases such as HIV, Ebola and influenza.” – Duke University

Lead by principal investigator Karen Cranston of Duke University, the Open Tree of Life project is based on almost 500 previously published trees, and is significant for a couple of reasons, not the least of which is its sheer size and scope, because while many other evolutionary trees have been created, many of them have not been available previously in a digital format for download or analysis.

By making this data readily accessible and editable, it is hoped that this work will help researchers to “fill in the gaps” between what we know and what we don’t know, and to clarify and resolve conflicts in certain branches of phylogeny. It will also serve as a starting point for adding new species as they are discovered and named.

“Twenty five years ago people said this goal of huge trees was impossible. The Open Tree of Life is an important starting point that other investigators can now refine and improve for decades to come.” – Douglas Soltis of the University of Florida, co-author

The Open Tree of Life is free to browse and/or download at, and the source code is available at GitHub. An article on the project was recently published at the Proceedings of the National Academy of Sciences of the United States of America (PNAS): Synthesis of phylogeny and taxonomy into a comprehensive tree of life. Six of the authors also took part in an AMA (Ask Me Anything) event on Reddit yesterday, fielding many questions about the project.

Please enable JavaScript to view the comments.

Leave a Comment