Yes (the later). A rat evolving into a cat, or vice versa, is incompatible with what is universally claimed and accepted by evolutionists. Rats and Cats both represent Orders of mammals (Rodentia -- rodents, about half of all mammal species; and Carnivora -- dogs, cats, bears & weasels, seals, etc). They are equal level taxa which (I believe) make their first appearance at roughly the same time. It has never been proposed, nor is it plausible, that one evolved from the other. They both share some earlier last common ancestor which would not be classifiable as either a "rat" or a "cat".
Please see post 135.
Though thank you, for your civility.
I don't believe we've met before. Odd given the amount of time we've both been on.