This is a confusing analogy because it's more like releasing 1,000 goats then wondering why they don't have an effect. My non-SME answer to this thread is: 1)

This is a confusing analogy because it's more like releasing 1,000 goats then wondering why they don't have an effect. My non-SME answer to this thread is: 1) 100 years is not that long in evolutionary terms; 2) cropland is large but not all land; 3) evolution is complex; 4) resistance is actually already observed in some species.