Evolutionary Chemistry: Getting There from Here

Gerald F. Joyce What takes place when the antibodies in the immune system evolve to become highly specific for certain antigens? In this issue, Wedemayer et al. have captured the x-ray crystallographic images of antibody molecules before and after they evolve into high-affinity binders for their ligand. In his Perspective, Joyce explains the apparent Lamarckian nature of this process, in which the shape of the mature binding site resembles the one induced in the original germ line antibody by the ligand.