Evolution in Action?

Could the life cycle of a frog not be considered a microcosm of the evolutionary process? What about the metamorphosis of a butterfly?

Originally posted by David C
Could the life cycle of a frog not be considered a microcosm of the evolutionary process? What about the metamorphosis of a butterfly?

Nope, no selection pressure. No selective death. It is a wonderful developmental process though and is indicative of the organisms that we evolved from. For example, during the embryonic phase all mammals exhibit a fish-like phase, with tail and everything...

edit; actually, I should say all chordates, rather than all mammals, although the mammals are a subdivision of the chordata. They / we also have gills during development...

Originally posted by scottishinnz
Nope, no selection pressure. No selective death. It is a wonderful developmental process though and is indicative of the organisms that we evolved from. For example, during the embryonic phase all mammals exhibit a fish-like phase, with tail and everything...

edit; actually, I should say all chordates, rather than all mammals, although the mammals are a subdivision of the chordata. They / we also have gills during development...

Selection pressure or selective death aside, this is the process, right? Brain pan expands, lungs develop, leg bones form, etc.?

Originally posted by scottishinnz
For example, during the embryonic phase all mammals exhibit a fish-like phase, with tail and everything...

I seem to recall that your conclusion -- that the embryonic phases like the fish-like
one support evolution on some scale -- is spurious. I mean, doctors studying biology
before the common era have been looking at miscarriages and surmising that we
were higher on the hierarchy of animals because we can see fish-phase, lizard-phase
or whatever.

I don't know much about embryonic development and what these phases entail, I
just remember that the 'we can see our evolutionary history in embryos' claim was
not well respected.

Or I could be totally inventing a memory!

Nemesio