One of the iconic metaphors of evolution is that of the ‘tree of life’ – it is the image we all have for how species relate to each other in evolutionary time. In a perspective article last year, David Penny (one of our editorial board) points out that this is originally a biblical phrase and not, as is sometimes assumed, one that was coined by Darwin. He also argues that Darwin’s use of this phrase has often been misinterpreted. Darwin used the phrase only once and then to denote competition between species (and groups of species) rather than relationships per se. To illustrate his point, he quoted the only explicit mention of it from a typically beautiful passage in the Origin of Species:
“buds give rise by growth to fresh buds, and these, if vigorous, branch out and overtop on all sides many a feebler branch, so by generation I believe it has been with the great Tree of Life, which fills with its dead and broken branches the crust of the earth, and covers the surface with its ever branching and beautiful ramifications”
Although Penny concludes that Darwin rejected the phrase ‘tree of life’ in favour of a more mechanistic and less simplistic view of evolution, the image of a tree as a representation of the basic evolutionary relationships between species (i.e. a phylogenetic tree) remains pervasive, compelling and incredibly useful. But, as the sheer number of known different species grows, it has become more and more difficult to visualise what these ‘megatrees’ really look like. Instead we are presented with small snapshot views of bits of the tree – basically what can fit on a flat 2 dimensional page. We were therefore delighted last month to publish a community page article by James Rosindell, from Imperial College London and Luke Harmon from the University of Idaho describing a new concept and software platform – OneZoom – that escapes the ‘paper paradigm’ and radically changes the way we can view and explore the whole tree. It uses fractal geometry, which essentially means you have an infinite amount of space to explore, and was inspired by the technology behind online maps, which allows you to zoom to a particular house on a specific street and then zoom out again to view the whole street, the town, the entire continent or even the whole world. To understand how it works, the authors have provided a tutorial on their site and on You Tube:
It has been three weeks since its publication and the article has been downloaded more than 14,000 times and, within only five days of the launch, the website hosting the platform was viewed more than 100,000 times. And the numbers here are a genuine reflection of the excitement that people from all sections of society had for the initiative (see the storify of the some of the tweets below).
OneZoom is just at the start of its life and features only the branch of the tree containing mammals (more than 5000 species) but gradually the authors will add other branches as data becomes available from other research projects such as the Open Tree of Life Project. Already the authors have added the conservation status of each species (information from the IUCN Red List) and you can connect straight to Wikipedia to find out more about your species. They even aim to make an app for OneZoom.
It is, as the authors acknowledge, not perfect but that’s not the point. Like the tree, it will evolve – and because all the software is open source, others will also be able to use and adapt it for their own purposes. Most important, however, it opens up a wholly new way to view and explore evolutionary history and is not only useful for research scientists but also educators, museums and any interested member of the public. It is humbling, for example, to see how Homo sapiens fits in – just one small and relatively recent leaf. As Joel Cracraft noted in a quote for the press release of the article:
“This will revolutionize how we teach and understand the Tree of Life. It is an invaluable tool for communicating the grand scope of life’s history to children as well as adults.”
And because we all thought it was just so cool, we used the article to launch a new series in the Community Page section of PLOS Biology called ‘Cool Tools’. We hope that this section will enable others to tell the story behind the creation of radically new ways to use and visualise research.
Finally, how the authors coordinated the launch of the site, with the publication of the article, a You Tube video and a dedicated twitter feed also provides a powerful example of how scientists can effectively communicate their research.