Christopher X J. Jensen
Associate Professor, Pratt Institute

Open Tree of Life allows experts and novices alike to explore “the” phylogeny

Posted 29 Sep 2015 / 0

Proceedings of the National Academy of SciencesSynthesis of phylogeny and taxonomy into a comprehensive tree of life

Open Tree of Life tree browser

Although I am far from being an expert in or huge enthusiast of taxonomy and phylogeny, this is a project worth exploring. By synthesizing thousands of published phylogenies, this project presents a complete tree of life that can be explored via the tree browser. One of the first things that strikes you as you play around with this browser is that the taxonomic groups we find most interesting and important represent just a fraction of the existing evolutionary diversity. Try this experiment: start at the base of the tree of life and try to find humans. I actually struggled with this because I really don’t know the classifications at the base of the tree very well, and there are a lot of side branches that are prominent in the tree but relatively unknown to most of us. With apologies to every one of my taxonomy teachers, I will confess that I had to search for humans and then step backward to see just how obscure our little branch of the tree of life really is. Looking at this tree is a great way of getting a broader appreciation of just how diverse life has become over evolutionary time.

I also found it interesting that this project uncovered major disagreements in the configuration of the tree of life (see the PNAS paper listed above for the full description of these disagreements). One would think that with all the genetic data that is now available we ought to be able to resolve the entire tree, especially closer to its base. But that’s not the case because evolutionary change has been so profound over time that the larger clades of the tree of life don’t contain enough homologies to allow clear resolution. It is fascinating that there is not agreement about the relationship between different animal groups (in other words the metazoa):

2015-09-29Figure 3B from Hinchliff et al. 2015
A Minor Post, Articles, Phylogenetics, Taxonomic Groups, Web

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