On falsificationism

Jerry Coyne asks, “Is falsifiability a good criterion for a scientific theory?”  My short answer is “No”, but I’ll try to flesh that out.  Coyne writes:

The “theory” of evolution, for example, could be disproven if we regularly found well-dated fossils out of the proper order (like mammals in the Devonian, for instance), if species didn’t have genetic variation to respond to selection, or if we often found “adaptations” in member of one species that were useful only for another species (e.g., a special nipple on a female mole that was only used for suckling mice).