“All codes we know the origin of are designed” That statement is not true. DNA is, in and of itself, the proof that this is not so. There are also many other examples in nature of “codes”, as such, which are not designed. The example I used about the colours of leaves could be cited as another, though certainly not as precise or encompassing as DNA but that is to be expected. The chemical and synaptic processes in a brain may well be the same. Your argument from ignorance is nothing more than the logical fallacy which anyone with an understanding of such things will immediately recognize it as.