Agreed.
As for the nylon digesting bacteria..
A loss in information can actually give a bacteria that ability. Same deal with developing resistances to antibiotics.
All that needs to happen is a digestive enzyme recieving a mutation which renders it less specific.. enzymes fit their respective molecules sort of like a key. A slightly less specific one could bond with a new molecule (for instance nylon) thus giving the bacterium the ability to digest a new substance. The enzyme is going to be a bit less efficient however, at performing its original job. Both nylon and proteins are broken down by breaking amide (ammonia derived) links.. so it's quite concievable that the enzyme could mutate to digest nylon.
Another example is sickle cell anemia. This mutates the red blood corpuscles into a sickle shape. This renders anyone with this mutation immune to malaria, however it makes the hemoglobin less efficient in carrying oxygen.. not the best thing! Sickle cell anemia is co-dominant, and people who are heterozygous for it have minimal harm from the mutation, while still reaping the benefit of malaria immunity.