The octopus's suckers were built from spare parts — genes borrowed from elsewhere in the body

An octopus sucker is a marvel: strong, sensitive and able to taste what it grips. A University of Tokyo team publishing in iScience has traced how such a tool gets built in a growing embryo — and found evolution working like a thrifty engineer, repurposing an old gene, Ets1, best known from other jobs in the body, to switch on where suckers form. The same trick of gene reuse may sit behind other cephalopod wonders, from colour-changing skin to the ink sac.