Graphical trees provide an intuitive way to display
hierarchically organized information like biological classifications
and phylogenies. Unfortunately, however, as static
trees incorporate increased information, they become cumbersome
Hyperbolic trees, which are a dynamic representation of
hierarchical structure, are an effective way to display complex
Deep Green will develop two different trees initially.
One is aimed at students and teachers, and will include only
a limited number of major branches but a lot of pictures,
text, and links to other sources of data. The other is aimed
at professional researchers, and will be as detailed a tree
as can be achieved with current, up-to-date knowledge, and
thus will contain thousands of branches. The latter will have
no pictures (as that would make the huge tree hard to download),
but there will be an intermediate webpage clickable from each
node, giving its justification including synapomorphies, links
to the actual data sets and literature in TreeBase, and biological
information to facilitate macroevolutionary studies (such
as estimated age of clade, amount of included diversity, etc.).
The maps at present are intended to be demonstrations of
the technique, not finished products. They were constructed
by Ray Cranfill and Dick Moe using data from Mishler et al.
(Ann. Missouri Bot. Gard. 81. 1994), Soltis et al. (Nature
402. 1999) and R. Cranfill (unpublished).
The trees were made using Site Lens Studio, which was donated
by Ramana Rao and Inxight Software Inc., in a collaboration
fostered by a TED (Technology,
Entertainment, and Design) conference in 2000.
Only browsers capable of using Java
applets will be able to view the trees. This means Netscape
4.05 or higher, and Internet Explorer 4.5 or higher, with
Java enabled. The files may be slow to load and start up,
especially the first time they are invoked.
The display can be moved around the screen by clicking or
clicking and dragging on the nodes. The display can be modified
by using the panel at the lower left of the screen. Searches
can be run by typing target words in a box in the panel. The
portion of the tree pertinent to the search will be highlighted
The Jepson Herbarium has an
example of hyperbolic trees used to display indexes for plant
distributions in California.