A method for the construction of a library of recombined polynucleotides from a number of different starting single or double stranded parental DNA templates is disclosed, wherein the starting single or double stranded parental DNA templates represent discrete points in a population of genes encoding evolutionary or synthetic homologues of a peptide having homologies ranging over a broad spectrum from less than 15% to more than 80%, said population exhibiting at least one identification sequence, and whereby said genes are subjected to a gene shuffling procedure to generate shuffled mutants of said population of genes representing additional discrete points between those of said starting templates.