How a Farmers’ Pest Is Making Scientists Rethink the Speed of Evolution

Over millennia, farming has transformed landscapes and ecosystems. As we transported plants across the oceans, we also unwittingly enabled the flourishing and evolution of other species. Some, like the cabbage white butterfly, spread with their host plants to every continent except South America and Antarctica. Others evolved to take advantage of the new resources on offer.

Railroad worms are one such pest. They have vexed small-scale apple farmers in North America for 180 years. As it happens, they are also beginning to offer evolutionary biologists a front-row seat to an accelerated form of evolution once thought to be impossible.