yes genetic algorithms are categorized under another field, so-called "DNA computing" (If I'm not mistaken)
No, they are not. DNA computing actually uses DNA to perform operations like splitting DNA strings, merging them and so on. It is not really something you can use, unless you have a laboratory. And it is not an algorithm, it is a kind of computer architecture.
Genetic algorithms on the other hand you can implement with every programming language you like. The algorithms mimic evolution, which is especially useful if you have to optimize something, that can't be done in the usual ways. You won't find an optimum with this approach, but you can get a good solution that is close.
I also found a book regarding this subject, called Machine Learning for Hackers, a quick look and I found Statistics as the main subject, and R language as the main tool being used, which is unlikely, in my point of view.
I'm used to using MATLAB for these purposes... I don't know maybe I should change the tools I use?
What exactly is it you want to do?