Sunday, February 22, 2004

The Deep Green Project

I'm doing more reading on diversity today, this time on plants. Thanks to the advent of molecular techniques our understanding of the relationships between taxa has been changing dramatically, and The Deep Green project appears to be leading the way for plants. See this Science article summarizing the project.

One of the coolest things about the project has to be their data presentation. Instead of using static trees on their website, they've decided to use dynamic hyperbolic trees. They only have two draft trees up right now, one for teachers and one for researchers (notes: Java is required, they're mainly for demonstration, the names aren't the easiest if you don't know plant taxonomy, and the research tree seems easier to use at the moment). The hyperbolic trees include a detailed phylogeny of plants, but you see only a few nodes at a time. You can drag nodes you're interested in to the center of the screen and more nodes related to that one become visible. It's intuitive; try it.

Want to see more detail about land plants?
  • Start on the research tree.
  • Drag the tree node at the base of liverworts over to the center of the screen
  • Liverworts are the most basal group of land plants; everything else at the base of the plant tree is algae.
  • If you can't see liverworts, drag the Charales node over until you can see liverworts.
  • Keep going and you'll reach Tracheophytes, the first group of plants to have true vascular tissue.
  • Continue on and you'll reach Lignosae.
  • Lignosae is the root node of what I believe have been called gymnosperms and angiosperms; the name refers to woody plants but I think it also is seed-bearing plants in this case.
  • You'll find Angiospermae (flowering plants) under Lignosae.
  • Interestingly they've split gymnosperms into multiple groups with Gnetophytes separate from the other gymnosperms (Ginkgos, Conifers, and Cycads).
  • Oh, I'd love it if someone more knowledgeable about plants could correct me on what the node Lignosae refers to. I know the word root refers to woody plants, but I thought lycopods and horsetails were also woody, yet they're not in that group, and from what I can tell only seed-bearing plants are in the group.

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