Marc Kirschner graduated in biochemistry from Northwestern University, moving to Berkeley for his doctoral research and with positions at Berkeley, Oxford University and Princeton before he took a professorship at University of California San Francisco where with Andrew Murray he did seminal research on the control of the cell cycle in Xenopus egg extracts that led to the discovery of how cyclin drives the cell cycle, and with Tim Mitchison on the dynamic instability of microtubules. In 1993 he moved to Harvard where in 2003 he became the founding Chair of the HMS Department of Systems Biology and was named the John Franklin Enders University Professor in 2009. The two books he wrote with John Gerhart, Cells, Embryos and Evolution (Blackwell, 1997) and The Plausibility of Life: Resolving Darwin’s Dilemma (Yale University Press, 2005), reflect his deep and longstanding interest in how biological systems evolve. Here he gives his view of the evolution of evolvability and its profound importance for understanding and applying biology. Marc Kirschner