There was a time not that long ago when sequencing a single gene would be hailed as a scientific milestone. But then came a series of breakthroughs that sped up the process: clever ideas for how to cut up genes and rapidly identify the fragments, the design of robots that could do this work twenty-four hours a day, and powerful computers programmed to make sense of the results. Instead of single genes, entire genomes began to be sequenced. This year marks the tenth anniversary of the publication of the first complete draft of the entire genome of a free-living species (a nasty little microbe called Haemophilus influenzae). Since then, hundreds of genomes have emerged, from flies, mice, humans, and