In this application, an “exon plate tectonics” design strategy was devised to assemble “equivalent” elements of structure (continental plates) with variability in the junctions linking them (fault lines) to explore global protein space. To create the corresponding library of genes, the breeding scheme of Gregor Mendel was adapted into a PCR strategy to selectively cross hybrid genes, a process of iterative inbreeding to create all possible combinations of coding segments with variable linkages. Genetic complementation in temperature-sensitive E. coli was used as the selection system to successfully identify functional hybrid DNA polymerases of minimal architecture with enhanced phenotypes.