by Greg Mayer
As some WEIT readers know, I am a specialist on lizards of the genus Anolis, and the genome sequence of the green anole, Anolis carolinensis, is in press in Nature in a paper by Jennifer Alfoldi, Federica Di Palma, and a cast of thousands (well, dozens). An advance copy has been posted online, along with a brief news item. The publication of the anole genome is a landmark event in comparative genomics, because it is the first reptile to be completely sequenced, as well as a landmark in anole studies
Anoles are a group of nearly 400 species found the southeastern U.S., throughout the West Indies, Mexico, Central and South America. Besides being species rich, they are diverse in ecology, behavior, morphology and physiology. Although the modal anole is an arboreal insectivore, some are terrestrial, some are aquatic, some eat fruit and small vertebrates, some live in deserts, and some live in rainforests. They also achieve high local species richness– up to a dozen or more species living in a small area– and very high abundance: James “Skip” Lazell, an eminent anolologist, likes to say that the anoles aren’t really common unless you can catch ten without moving your feet. Perhaps the most striking evolutionary phenomenon in anoles is community- wide convergence: on the islands of the Greater Antilles, whole suites of sympatric lizards have evolved independently, but each suite contains species of characteristic morphology and behavior associated with particular stations in the habitat (each characteristic type being called an ecomorph).
Anole Annals, your source for the latest information on Anolis lizards, is providing a lot of coverage of the event, with a guide to many of the genome-related posts by Jon Losos here, the announcement of the advance posting by Rich Glor here (see also here), several posts on early genome results here, here, here, here, and here, and my own contribution, on the history of the study of anoles, here.
One of the first results of most interest to me has been the development of primers that allow sequencing of many genes for comparative phylogenetic studies. The tree below from Alfoldi et al., based on these new sequences, confirms a number of things we already knew, but also resolves a number of difficulties in anole phylogeny and biogeography.
The green anole itself, Anolis carolinensis, is the most widespread, and perhaps only native, species of anole in the United States. It is a member of an originally Cuban species group that has dispersed widely to surrounding islands as well as the main. Rich Glor has a review of carolinensis‘s origins at Anole Annals. The story of how carolinensis was chosen to be the first reptile sequenced, mentioned in my post, is detailed by Jon Losos.
Alfoldi, Jessica, Federica Di Palma, Manfred Grabherr, Christina Williams, Lesheng Kong, Evan Mauceli, Pamela Russell, Craig B. Lowe, Richard Glor, Jacob D. Jaffe, David A. Ray, Stephane Boissinot, Andrew M. Shedlock, Christopher Botka, Todd A. Castoe, John K. Colbourne, Matthew K. Fujita, Ricardo Godinez Moreno, Boudewijn F. ten Hallers, David Haussler, Andreas Heger David Heiman, Daniel E. Janes, Jeremy Johnson, Pieter J. de Jong, Maxim Y. Koriabine, Peter Novick, Marcia Lara, Chris L. Organ, Sally E. Peach, Steven Poe, David D. Pollock, Kevin de Queiroz, Thomas Sanger, Steve Searle, Jeremy D. Smith, Zachary Smith, Ross Swofford, Jason Turner-Maier, Juli Wade, Sarah Young, Amonida Zadissa, Scott V. Edwards, Travis C. Glenn, Christopher J. Schneider, Jonathan B. Losos, Eric S. Lander, Matthew Breen, Chris P. Ponting & Kerstin Lindblad-Toh.2011. The genome of the green anole lizard and a comparative analysis with birds and mammals. Nature in press. (advance post)
Glor, R.E., J.B. Losos, and A. Larson. 2005. Out of Cuba: overwater dispersal and speciation among lizards in the Anolis carolinensis subgroup.Molecular Ecology 14:2419-2432. (pdf)
Losos, J.B. 2009. Lizards in an Evolutionary Tree: Ecology and Adaptive Radiation of Anoles, University of California Press, Berkeley. (publisher)