Mouse genetics and computer modeling suggest that a reaction-diffusion mechanism defines digit pattern.

Almost 2 decades before the Large Hadron Collider at CERN caught a glimpse of the long-sought Higgs boson, physicists began planning a machine that would examine the Higgs in detail and probe for even more elusive particles. Now, the design for that machine, the International Linear Collider, is nearing completion. But can it be built?

The suite of genes that governs limb development includes some of the best-studied in the field, but explaining why a hand has five fingers—and why some mutations cause more or fewer to form—has left developmental biologists perplexed. Now, scientists may have an answer from a set of equations noted mathematician Alan Turing developed 60 years ago.