I want to know the answer to the following question:
Where did most of the current earthworms in glacial areas come from?
All the background I'm provided with is that "In the glaciated areas of North America, for example, almost all native earthworms are thought to have been killed by the glaciers and the worms currently found in those areas are all introduced from other areas, primarily from Europe, and, more recently, from Asia.". Is that enough to answer the question?