A mystery is unfolding in the laboratories and grain fields of Oregon. Stalks of wheat that hadn't been planted and wouldn't die were found growing among a farmer's crops. Tests have revealed that the peculiar wheat included an illegal gene modification that made it resistant to a certain herbicide — something that shouldn't have existed within a commercial US grain field. Now the USDA's Animal and Plant Health Inspection Service is trying to figure out how it got there and who it came from.

Early lab results show that the grain is a match for a strain that Monsanto tested between 1998 and 2005, but how it got there remains unclear. Both Monsanto and the USDA say that the wheat is safe for growth and consumption, despite its ban in the States. But that doesn't mean there's no reason to be concerned. Bloomberg Businessweek has a brief overview of the history of genetically modified crop outbreaks, why critics are worried, and what this could mean economically. The situation has already become a problem: Japanese orders for 25,000 tons of wheat have already been canceled.