© WESLEY BEDROSIAN/THEISPOT
In 1995, researchers published the world’s first complete genome sequence of a free-living organism, that of the bacterium Haemophilus influenzae. The sequences of many model organisms, including Escherichia coli and Arabidopsis thaliana, followed shortly thereafter, and by 2001, the Human Genome Project had completed the first draft of a person’s entire DNA sequence. With this new capacity to decipher the genetic blueprint for any organism, some researchers believed they held the key to explore the inner workings of every species on Earth—guided by just a single reference genome per species.
“It was not really in the accepted thought that you’d have to [sequence] more than one of anything,” says Hervé Tettelin, an associate professor of microbiology and immunology at the University of Maryland. “The human ...