From bacteria to buffalo and mushrooms to minke whales, researchers have for the first time been able to piece together the evolutionary tree of all 2.3 million named species of animals, plants, fungi and microbes. This incredible tree of life shows the relationships among all known living species, tracing the origin of life through 3.5 billion years of evolution.
Created through the collaboration of eleven institutions, this first draft is a composite of roughly 500 smaller trees that have been published over the years and now combined into a single tree that is available free online for anyone to use or edit. “This is the first real attempt to connect the dots and put it all together,” said Karen Cranston from Duke University in a statement. Cranston was one of the principle investigators of the project, which has been published in the Proceedings of the National Academy of Sciences. “Think of it as Version 1.0.”
The tree of life is effectively a diagram that shows the evolutionary relationships between all living organisms. The branching indicates how different species all descend from a common ancestor. Not just useful for working out how different species are related, they can also be used to assess the origin and spread of infectious diseases, or discover new antibiotics, among other things.
While this initial draft uses data from 500 separate smaller trees, far more data has already been published, accounting for tens of thousands of evolutionary – or phylogenetic – trees. The problem is that only a fraction of those, the researchers estimate about one in six, have deposited their data in a digital, downloadable format that can then be used and added to the single super tree. Most are published as PDFs and other image files that are simply impossible to enter into the new diagram. The researchers see this as the first step in developing the most comprehensive archive of all life on Earth.
Another major problem that they had to overcome was simply accounting for the changes in names, alternate names, misspellings and abbreviations of species used by different researchers and institutions. Spiny anteaters, for example, once shared their scientific name with a group of moray eels. For this reason the whole project is open access, meaning that anyone can go in and edit the data if and when changes are needed. The researchers refer to it as the “Wikipedia” for evolutionary trees.
The resulting diagram has allowed the researchers to see not just what we know about life on Earth, but what we don’t know too. To fill in these gaps, particularly in the branches that contain the insects and bacteria, they hope to develop software that will allow researchers to enter the tree and add in the data when new species are discovered or named.
“It's by no means finished,” concludes Cranston. “It's critically important to share data for already-published and newly-published work if we want to improve the tree.”
Image in text: This circular family tree of Earth’s lifeforms is considered a first draft of the 3.5-billion-year history of how life evolved and diverged. Duke University.