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!

4 comments:

Dan Warren said...

That is a crazily expensive book. However, it looks like most (all?) of it is available for free online as PDFs. Kudos to the authors for doing that, it makes a big difference for those of us who can't drop $200 on a book.

Leonardo de Oliveira Martins said...

There is a review of this book on TREE. My impression, from the review, is that the database is more interesting (in the long term, at least) than the book.

Frank Anderson said...

I was just going to comment that I'd reviewed the book for TREE, and Leonardo had already mentioned it.

The book is pretty good. No one is qualified to review all of the taxon-specific chapters, but the quality of those chapters, while variable (it is an edited volume, after all), seemed pretty high to me. A couple of the introductory chapters are nice reviews of the process of creating timetrees, though I thought one in particular could have been great if it had just been a bit more accessible. I prefer the idea of a regularly updated online database to a book, though -- this field is developing so rapidly that many of the date estimates in the book will be obsolete within a few years.

Glor said...

Thanks for the review Frank, and for adding your thoughts here.