This circular family tree, which maps out all known life on Earth, is considered a first draft. (Photo: opentreeoflife.org)
All life on Earth is related, from tiny bacteria to 90-foot blue whales. We're one big family, but we've done a terrible job keeping up with our ancestry records.
To be fair, the planet has hosted life for 3.5 billion years, and apparently no one tried to categorize it all until we came along. We're still working on that today, compiling diagrams known as "trees of life" that trace species back to their common ancestors and help us map the evolutionary relationships among various creatures.
Biologists have drawn thousands of these trees over the years, although they tend to focus on specific branches of life. Many are published as PDFs, which means their data are not digitally available for researchers to merge with other maps. But now, an ambitious new project has grafted nearly 500 of these smaller "trees" into the most comprehensive and accessible map of life ever made. It already boasts about 2.3 million species, and its creators say they're just getting warmed up.
"This is the first real attempt to connect the dots and put it all together," principal investigator and Duke University researcher Karen Cranston says in a press release about the Open Tree of Life project. "Think of it as Version 1.0."
Eastern red bats are sometimes listed by two names: Lasiurus borealis and Nycteris borealis. (Photo: Josh Henderson/Flickr)
One of the project's biggest challenges was dealing with our species' jumbled, often redundant history of naming other species, the researchers say, as seen in animals like the eastern red bat, which has been listed under two different scientific names. But its goals go far beyond taxonomy: Studying Earth's family tree is key to a wide range of important scientific efforts, from increasing crop yields and fighting infectious diseases to understanding the origins and evolution of life.
The new map — "a gigantic 'supertree' that encompasses all named species," as its creators put it — is described by a new study in the Proceedings of the National Academy of Sciences. But the tree itself is also freely available at opentreeoflife.org to browse or download, assuming you don't get lost in its thicket of data.
Despite the unprecedented scope of this project, its architects are careful to point out it still has lots of limitations. While it reveals the connections among a dizzying array of organisms, even the best archives of raw genetic sequences contain DNA from fewer than 5 percent of the tens of millions of species thought to inhabit Earth.
"As important as showing what we do know about relationships, this first tree of life is also important in revealing what we don't know," says co-author Douglas Soltis, a principal investigator at the Florida Museum of Natural History. Beyond letting anyone see and use their data, the tree's creators are also developing software that will let other researchers update the tree as new data come in.
"Twenty five years ago people said this goal of huge trees was impossible," Soltis says. "The Open Tree of Life is an important starting point that other investigators can now refine and improve for decades to come."