The Tree of Life is constantly growing, according to its managing editor at the University of Arizona, Katja Schulz. The expansive Internet project is a genealogy that provides information on the characteristics of life on Earth. Started in 1996 by UA Professor David Maddison as a tool for scientists, the site has recently begun experimenting with allowing schoolchildren and members of the public to interact with the database in a number of ways. Visit tolweb.org/tree/ to find out more.
What's unique about the Tree of Life Project?
The Tree of Life Project is a digital library project about biodiversity, about different kinds of organisms, ranging from microorganisms to plants and animals. Its intent is to eventually cover all organisms that exist, and that have ever existed and have ever been described. There are other projects about organisms and about biology out there, but our take on things is very phylogenetic. It's based on the evolutionary relationships between the organisms. So both our system architecture and the navigational structure of our site actually reflect these evolutionary relationships. The pages are linked together in the form of evolutionary hierarchies.
So how is this tree arranged?
We have pages whose content reflects the different levels of the hierarchy of life. For example, we have a root page that will eventually--once we get more content up--provide information about the characteristics of all of life. And then on that root page, you have a number of navigational choices going up and exploring the subgroups of life. There are currently, we think, about four major subgroups of life: the true bacteria, the viruses, the archaeans and the eukaryotes. We provide links to the pages that describe each of those. You can move up and down the tree exploring, starting out at the root, which is like this huge group of organisms, and going higher up the tree to ever less-inclusive groups or subgroups of life. Our idea is that we want to present the whole tree of life as an integrated whole. As people navigate through our project, we want to instill them with the sense of genetic connectedness between all kinds of organisms. You know, humans are like one leaf on this gigantic tree, which also includes slime molds and trees and cockroaches and all these other organisms.
How many organisms are on it right now?
Right now, it's very incomplete. We have about 4,000 scientific Web pages. Not all of them have hard-core content in the form of a narrative. So the minimum of what they will have is a tree or sometimes just a list of taxa of the subgroups that are included, and also they'll have Internet links, references, maybe a couple of pictures to show what the organisms look like. Those 4,000 pages--a subset of them will have full-on descriptions of what the organisms are, and others might just have a few data here and there about the organisms. Those 4,000 don't even scratch the surface, because currently we have about 1.8 million species that have been described--and probably there's an order of magnitude out there that still needs to be described.
That's a lot to cover.
But at the same time, we have pretty wide coverage compared to what else is out there. You know, there's no book out there that would have all of that information.
How are school children involved?
Last year, in the context of an NSDL (National Science Digital Library) project, we started opening up the project to the people. Now anybody can contribute to the Tree of Life. ... Right now, we're working with a number of schools in Tucson. We have kids in classrooms--and not just in Tucson. We're also working with schools in New Jersey, Canada and Australia. ... Sometimes there are investigations that they do in the classroom, or they write stories, or some write poems or songs. Basically, we want to collect people's ideas about organisms, whether they are scientific or artistic, creative--whatever.
I noticed you've collected some nonscientific things already.
Yeah, we've got about 100. We call those things "tree houses," because we attach them to the branches that are created by the scientists. ... Some of them (tree houses) are built by scientists, but most of them are built by school children or just people who have something to say about organisms and want to express themselves.
There was a song about a sea star.
There are songs, there are poems, there's a page about origami. There are a lot of cool little stories that kids come up with. The idea is that just by giving kids the opportunity to publish something, they have to think about what they might have to say. They learn on so many different levels.