Those interested in the evolution of annelid worms (like earthworms) should check out a new paper in this week's Nature by Struck et al. They examined a huge dataset of proteins from 34 different worms, and they came up with a pretty well-supported phylogeny. When I learned about the segmented worms in high school (back in "the old days"), I learned that they were divided into the oligochaetes, polychaetes, and hirudineans (leeches). This new phylogeny recognizes two major divisions: the Sedentaria and Errantia. The traditional leech/oligochaete groups are nested within the Sedentaria, and the polychaetes are spread out in both divisions.
And if you don't care about worm phylogeny, I will waste no more of your time with this post. Thanks for reading this far and tolerating my random interests.
Struck et al. 2011. Phylogenomic analyses unravel annelid evolution. Nature 471:95-98.
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