They’re called “synthetic biologists” and they boldly claim the ability to make never-before-seen living things, one genetic molecule at a time. They’re mixing, matching and stacking DNA’s chemical components like microscopic Lego blocks in an effort to make biologically based computers, medicines and alternative energy sources. The rapidly expanding field is confounding the taxonomists’ centuries-old system of classifying species and raising concerns about the new technology’s potential for misuse. Though scientists have been combining the genetic material of two species for 30 years now, their work has remained relatively simplistic. So a new breed of biologists is attempting to bring order to the hit-and-miss chaos of genetic engineering by bringing to biotechnology the same engineering strategies used to build computers, bridges and buildings.