Friday, June 12, 2009
One Big Chronogram
S. Blair Hedges, Sudhir Kumar, and other members of the Timetree consortium have just announced the public release of results from the Timetree of Life project, an effort to provide a comprehensive evolutionary timescale for life. These results are available in the form of a free web page and a ridiculously-priced $200 book (compliments of Oxford Press). I've only done a little bit of poking around on the web page, but so far it seems like an impressive and remarkably easy-to-use resource. By inputing the names of two taxa of interest users can obtain a comprehensive list of molecular-clock based age estimates for the node connecting these taxa, including information on the data underlying these age estimates and references to original source material in the primary literature. Perhaps the most obvious limitation of this database is that it is comprised exclusively of age estimates from molecular data, with no direct information on node ages from the fossil record. Regardless of this and other limitations, there can be no denying that this project is an important step toward a deeper understanding of how and why biological diversity has accumulated over time. Ok, now go play with the Timetree!