A research team builds robots from living cells

ROBOTS COME in all shapes and sizes. Some are humanoid. Others resemble animals. Many are just a jumble of arms slaving away on a production line. But one thing all robots have in common is that they are mechanical, not biological devices. They are built from materials like metal and plastic, and stuffed with electronics. No more, though—for a group of researchers in America have worked out how to use unmodified biological cells to create new sorts of organisms that might do a variety of jobs, and might even be made to reproduce themselves.There are several ways to tinker with living organisms. Selective breeding and, more recently, genetic engineering permit the production of novel plants and animals for agriculture and horticulture, and as pets. Souped-up bugs for industrial processes can also be made in these ways. Researchers are working, too, on growing isolated animal organs for testing drugs and eventually, perhaps, for transplant surgery.