Most convincing evidence for evolutionary theory

I think in the broadest terms possible it is correct to say that evolution will take place wherever there is replication with modification and the opportunity to adapt to changes in the environment external to the replicating entity that affect the ability of modified replicas to themselves replicate.The most obvious observable example we have of these mechanisms is life on Earth.
There is no reason whatsoever however to think that evolution is restricted to life or to this planet.Anything that replicates with modification and has the opportunity to adapt in such a way as to make some modifications more successful at replicating than others will lead to evolution.Is that universal enough?Edited by Straggler, : No reason given.

Are humans who cannot speak for whatever reason any less human?Could we not define any particular characteristic of any animal and say that said characteristic makes it unique and special. Surely the only reason we would think speech is so special is because it is our speciality?Do other animals not communicate verbally? At what point does that become speech? (dolphins, whales, chimps etc. etc.)

How exactly?At what point in infant development does this transition from communication to speech occur (for example)?I still have issue with you arbitarily deciding that speech is the most important attribute that seperates us from all other living things but until the difference between communication and speech is defined this is fairly meaningless anyway.Edited by Straggler, : Dopey spelling