Does Life Use a Non-Random Set of Amino Acids?

If chance and necessity are seemingly inadequate, either on their own or in co-operation, what about the causal powers of agent causality? If, in every other realm of experience, such features are routinely attributed to intelligent causes, and we have seen no reason to think that this intuition is mistaken, are we not justified in positing and inferring that these systems we are finding in biology also originated at the will of a purposive conscious agent?