Then, does (can) maths EXPLAIN what happens in nature?
The paradox here resides on the definition of "explanation". As Doug posted, math is just a descriptive language. It does not explain, it allows us to build a model which we can use to predict things. When the prediction matches the measurements accurately enough, we have a working theory. That, people call an "explanation".
Isn't DNA code; math? Which leads to the bigger question nobody wants anyone to ask. Who DID the math?
DNA code is just that: a code. It describes the steps a cell uses to build elements, normally proteins.
Codes are, generally speaking, mathematical objects. That is, we can build a one-to-one relationship, a bijection, between a particular DNA molecule an a mathematical object which is easier for us humans to handle. Then, we can study that mathematical object and try to build a model on the relationship between that object and a particular protein. We are not that far.
Your last question is, obviously, related to religion. Please consider that mathematics are not suited to answer that particular question. They can neither prove nor disprove any answer.
