The U.S. Environmental Protection Agency was ordered by a federal appeals court on Friday to take a fresh look at whether glyphosate, the active ingredient in Bayer AG's Roundup weed killer, poses unreasonable risks to humans and the environment.

If I feel a sudden pain in my ankle while walking down some stairs, I'm not going to the EPA or the 9th Circuit to figure out what caused it. I'm going to the hospital. If the first doctor tells me that my ankle sprain was caused by aliens, I'll seek a second opinion. If the new doctor says there's no evidence that tigers are responsible for my ankle pains, that's probably true, but I'll likely need a third opinion to get out of the mess.