The first publication of the Open Tree of Life Project is a piece of scientific correspondence published in Nature. The letter very concisely summarizes a tremendous amount of bibliographic/database research by Open Tree post-docs Bryan Drew, Romina Gazis, Patricia Cabezas Padilla, and Kristen Swithers, which found that the vast majority of phylogenetic studies are not represented by alignments and treefiles in publicly-accessible electronic databases such as TreeBASE or Dryad (although, for molecular studies, the sequences are available in GenBank). Changing this situation is one of the core goals of the Open Tree project.
Drew, B. T., R. Gazis, P. Cabezas Padilla, K. S. Swithers, D. E. Soltis, D. S. Hibbett, K. A. Crandall, and L. A. Katz. 2013. Data deposition: Missing data mean holes in the tree of life. Nature 493: 305 (correspondence).