Conventional genetic engineering is a lengthy process in which genes are altered one by one, often over successive generations of organisms. That makes radically changing a genome a daunting proposition. But the newly developed techniques allow researchers to edit genomes on a computer, subtracting or adding genes by literally cutting and pasting them in a file. It's more like word processing than the traditional lab work involved in culturing and screening generations of organisms. The researchers can then perform the genetic equivalent of printing out the file, at which point they're able to transplant the result--a new genome--into existing cells. These steps dramatically speed up the engineering process; it might take just weeks to complete experiments that previously would have taken months or years.