Photograph by Tom Kochel, courtesy of the Department of Biochemistry and Biophysics, The University of California San Francisco. · CC BY 2.5

A biochemist whose textbook Molecular Biology of the Cell became the standard reference for a generation of students, Alberts built his research career studying the protein complexes that let cells replicate their chromosomes accurately. He served as president of the National Academy of Sciences from 1993 to 2005 and as Editor-in-Chief of Science, using both posts to push for evidence-based public policy, and received the National Medal of Science in 2014.