How does evolution explain metamorphoses?

Answer 1

Sorry to jump straight onto this as a newbie, but it got me thinking...

The problem with metamorphosis seems to come from the assumption that the process evolved in the same order that it occurs.

for example, just because the creature becomes a chrysalis then a butterfly, doesn't mean that the chrysalis evolved before the butterfly.

to propose a hypothetical example...

A tadpole becomes a frog without the need for a chrysalis.

The frog continues to evolve, so that the difference between frog and tadpole increases, and the metamorphosis becomes more complicated.

As metamorphosis becomes more complicated, the vulnerability of the organism during the process makes it advantageous for it to be better protected.

The individuals with, for example, tougher skin, (at least during the process)are more likely to survive.

The tougher skin becomes exagerated until it is distinguishable from the rest of the organism.

once the chrysalis has evolved, the extent of the metamorphosis can evolve until it entails a complete decomposition.

Any holes in there?