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Frequently Asked Questions

Can I use images from the Tree of Life in my own projects?
The images on the Tree of Life are protected by international copyright law. The copyright for individual images is generally held by the image contributor, so if you want to use any image from the ToL website, you need to contact the relevant copyright owner to negotiate a permission grant or license. More details are provided on the Tree of Life Copyright Policies page.
ToL logo

If you would like to use an icon to link to the Tree of Life, you can download this image and put it up on your web site.

Can I put a link to the Tree of Life on my own web site?
Anybody can link to the Tree of Life. You do not have to ask for permission. You can link either to the home page or to any other page on the site. Please do not link directly to image files. If you want to link to a ToL image, you can either link to the ToL page on which it is shown, or you can link to the data page for the image, which opens in a separate window when you click on the image. When linking to image data pages, you can use simple urls based on the image ID, which is listed in the image data. For example, to link to this image, which has the ID 4651, you can use this link: http://tolweb.org/media/4651
How can I find the Tree of Life page for a particular group?
The page on Finding Things on the Tree of Life provides instructions.
Why is there no Tree of Life page for guinea pigs?
The current version of the Tree of Life is very incomplete, and many large and important branches are still not covered by our project. Progress has been slow in recent years for two major reasons:
  • The Tree of Life has only recently been able to find a significant source of funding permitting the hiring of a small group of full-time and part-time staff.
  • We carefully select our authors in order to maintain a high standard in the content we provide. Since we focus our recruitment efforts on the principal experts for each particular group, our contributors are among the busiest people in the business. Sometimes, we have to wait for quite some time until committed authors find the time to finish the manuscript for their ToL page.
With the increased technical and administrative support we can now provide at the home site, we hope that the Tree of Life will soon show a significant growth spurt.
Can I get my hands on the tree structure you use for the ToL site?
You'll find a link to a static XML file with the current ToL structure on the Downloading the ToL Tree Structure page.
How do I cite a Tree of Life page or the Tree of Life Project as a whole?
The answers to these questions are provided on the Citing the Tree of Life in Publications page.
How are Tree of Life authors selected?
Tree of Life authors are generally invited to contribute to the project by the coordinators of the containing group. The coordinators are instructed to base their choice on a person's scholarly expertise as demonstrated by their ongoing research program and/or publication record. For more information on this topic refer to the page on Contributing to the Tree of Life.
How can I become a Tree of Life contributor?
  • If you are a biologist, and you are interested in authoring or coordinating the Tree of Life pages for your favorite group, the best thing to do is to contact us by sending an e-mail message to Tell us what group of organisms you are interested in contributing to the ToL and the nature of your work on the group. We can pass your offer to the relevant coordinator for consideration and give you more details about what's involved.
  • If you are not a biologist, you may still be able to participate in the Tree of Life project by providing images, suggesting links, etc. If you think you have something to contribute to the Tree of Life, please send a message to Please be warned that we have only a small staff, and our answer may sometimes take a little while during very busy times.
I have found an error on a Tree of Life page. How do I report it?
Send an e-mail message to the page author and to We appreciate our visitor's help in stomping out little bugs.
Can you put a link to my web page on a Tree of Life page?
Sure, if it's relevant and good. Send a message with your url to indicating what your page is about and suggesting the ToL page that should have a link to it. Please be warned that we have only a small staff, and adding the link may take a little while during very busy times.
Can I put a link on my own web site to the ToL home page or another page on the ToL site?
Anybody can put links to our site on their own web pages. Of course, we are not responsible for links to our site created by other people. You can link either to the home page or to other pages on the ToL site. The urls for our web pages are generally permanent, and we create redirects if we have to change an address.
My term paper is due in 25 minutes, and I really need to find out everything there is to know about alligator teeth. Could you please send me a summary on this subject? Seven pages, double-spaced would be ok, fifteen references minimum. I'm waiting, thanks!
Sorry, we don't generally have the time to provide answers to specific questions about organisms.

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