The obvious answer is because there's a very precise combination these protein molecules must form.......so precise that we couldn't possibly hope to stumble onto it through a process of trial and error......
Well for one the cells are now specialized.This allows for greater capabilities and hence a survival advantage.Since cells are specialized the organism can now devote those specialized cells to specific tasks and now the evolution of further cell specialization is greatly enhanced.
[W]hen people thought the Earth was flat, they were wrong. When people thought the Earth was spherical they were wrong. But if you think that thinking the Earth is spherical is just as wrong as thinking the Earth is flat, then your view is wronger than both of them put together
Indeed. I understand mitochondria have a slightly different code, which substantiates endosymbiosis as the explanation of their origin.
It's not just mitochondria, there are about sixteen known varients.
But the fact that the standard code is shared by almost every organism is a pretty powerful argument for common descent.
Not only that but the coding pattern itself seems to have been shaped by natural selection - in that of the possible codings the ones which are used have a high 'fault tolerance' in that errors will tend to produce either the same amino acid or a similar one.
Ok, you can turn down the pedantism, a bit. I never said it was just mitochondria, and I never said that every single organism uses the Standard Code. I understand a need to be precise, or to prevent misunderstanding, but you seem to be taking a fairly strident tone against assertions I'm not making.