Many research groups successfully rely on whole-gene random mutagenesis and recombination approaches for the directed evolution of enzymes.

In vitro molecular directed evolution of enzymeis a new strategy in the engineering of novel biocatalysts, which mainly mimics the process of natural evolution to generaterandom mutation in the genes coding for useful enzymes by the techniques of error-prone PCR, and then in vitro recombinespositive mutations through various methods such .

Several receptor binding sites of LT were mutated randomly, then the R46,S106,L130 combined site-directed random mutation library and S106～F110 region random mutation library were displayed on a filamentous phage surface.

To construct the combined site_directed random mutation library of recombinant human Lymphotoxin (rhLT) for in vitro molecular evolution study, and to study the structure and function relationship.

Based on the theory of nature choice and the hypothesis of mutation of neuter, summarized some questions of Darwinism, and discussed the heritable materials? the changing of circumstances and the varieties of the organisms, put out some new ideas of evolution of species in the biological study world.

Gene expression programming(GEP) is a genotype/phenotype system with non-coding regions in genome where possible neutral mutations would be accumulated.