Or animals might need additional tricks to transport the morphogens across tissues, or to make patterns sharp and crisp. Scientists also see dizzyingly complex instances where Turing patterns are ...

Scientists normally explain the spectacular diversity of animal patterns by pointing to genetics. But a study in Nature suggests that, at least for crocodile heads, different forces might be at play.

Sophie Cohen-Bodénès knew she was onto something when she saw the cuttlefish extend two arms upwards while twisting its six others together. It was making what she calls the “up” sign – and, ...