In 2006, Hannah Seidel, a graduate student in Leonid Kruglyak's lab at Princeton University, performed an experiment that hundreds of C. elegans biologists had done before: She crossed two common worm strains, and looked at the progeny. Only this time, unlike previous experimenters, Seidel inspected the Petri plates a bit more carefully. And in the second generation, she noticed scores of dead eggs.
Seidel had decided to perform the experiment after evolutionary geneticist Matt Rockman, then a postdoc working with Kruglyak, had crossed the same parental strains to construct more than 200 recombinant inbred worms for mapping genes. He was inspecting the resulting worms' genotype data when he noticed that on the left arm of chromosome I, one of the parental strains had contributed far more than its fair share of DNA: The SNP ratio was nearly 50:1, not 50:50, as he expected. Rockman "basically gave me some worms and ...