Convergent Mutation?

Was watching the Godzilla animated series on Netflix yesterday when a thought entered my mind. Now we all know that Zilla gets no respect whatsoever. He is reviled every where he goes (hell, one guy around here calls himself Zilla hater). I think he's a fairly cool monster on his own. But all the hate makes me reluctant to even talk about him, so i'm quiote nervous bringing up this random bit of speculation.

As a student of paleontology, i'm no stranger to evolution or all the wierd life forms it has produced. Now there is one particular brand of evolution that is particularly interesting: convergent evolution. Convergent evolution posits that animals completely unrelated to each other will develope similar traits to meet similar needs. One of the best examples is Thylacosmilus. It looks like a sabertooth cat (not sabertooth tiger. no such thing). It has powerful limbs, a long tail, and enourmous 7 inch canines. But here's the thing: it's not a cat! It's a marsupial. That's right. There was a sabertooth marsupial. How? For much of the last 65 million years South America was an island continant, cut off from the rest of the world. With no cats or dogs or bears, marsupials evolved to fill those roles. So no sabrtooth cat meant the slot was free so marsupials filled the void. There are many other wonderful examples but Thylacosmilus is, imo, one of the most striking examples.

But could this really be restricted to evolution? Watching  a creature who was obviously not Godzilla being called Godzilla made me think. I went beyond the usual drama about movie rights and different studios and instead tried to think in their universe. Why would people call this thing Godzilla?It has dorsal spines like Godzilla. It comes from the sea like Godzilla. It breathes fire(?) like Godzilla (at least in the animated series). It even sounds like Godzilla. But it isn't Godzilla. Why so many shared traits with the King of the Monsters? Could convergent evolution extend to atomic mutation? Could nuclear radiation produce similar traits in animals as distantly related as a dinosaur(?) and an iguana?

This then led me to the radical possibility. In the movie Nick whats-his-face says that Zilla was created by nuclear tests in French Polynesia. Do we know for sure? Given the failure of the film a franchise with more lore was never developed. What if Zilla is so much like Godzilla from a combination of convergence... and shared origin? What if the nuclear bombs meant to kill Godzilla also lead to the mutation of the iguana who became Zilla?

At this point i'm just pulling stuff out my a$$. Perhaps i just like Zilla enough to consider his origins beyond the 2 sentaces given in the movie. Just thought i'd share that with y'all.