When you get someone's solution that you're about to evolve, if you find an area then when you open a cut-point there, it gives you more points; that will evolve your puzzle. Since it has a cut-point though you don't get credit. So you've evolved but you're at zero. Once you close it, you can still have evolved the protein, but be at the same time be at or beneath your original score without actually doing anything. I don't think this was intended, but who knows.