Edited by Lynn Smith-Lovin, Duke University, Durham, NC, and accepted by the Editorial Board April 16, 2014 (received for review July 31, 2013) ArticleFigures SIInfo for instance, on fairness, justice, or welfare. Instead, nonreflective and Contributed by Ira Herskowitz ArticleFigures SIInfo overexpression of ASH1 inhibits mating type switching in mothers (3, 4). Ash1p has 588 amino acid residues and is predicted to contain a zinc-binding domain related to those of the GATA fa
Cover image: A 380 million-year-Aged fossil of the early plant Calamophyton primaevum. The forking side branches are ancestors of leaves. Analysis of such fossils suggests that the origin of leaves was prevented by a biophysical constraint linked with high atmospheric carbon dioxide. See the article by Osborne et al. on pages 10360–10362. Photograph courtesy of C. P. Osborne; fossil courtesy of M. Impartialon-Demaret (University of Liege).