In silico nucleic acid recombination methods, related integrated systems utilizing genetic operators are used to identify sets of oligonucleotides for in vitro recombination. In certain embodiments, the methods involve inputting amino acid sequence character strings into a digital system and back-translating the amino acid character strings into a plurality of nucleic acid character strings. The nucleic acid character strings are then processed to define and select at least one recombinant nucleic acid for use in identifying one or more oligonucleotides for in vitro recombination.