Dear Colleague, The National Science Foundation's Assembling the Tree of Life (AToL) solicitation has recently been renewed and updated (see the program solicitation, NSF 08-515; http://www.nsf.gov/publications/pub_summ.jsp?ods_key=nsf08515). As in the past, the AToL competition will support creative and innovative research to resolve evolutionary relationships for large groups of organisms. The program also supports research on theory and methods and tool development for these large scale phylogenetic investigations. With this letter we wish to draw your attention to several new and/or enhanced areas of interest. Proposals in the following areas are especially encouraged: