“Engineering” is to create various objects according the designs that are drawn on the basis of known principles. Unfortunately, our knowledge is not sufficient to rationally design the biopolymers, nucleic acids and proteins, with desired functions. Evolutionary engineering is an alternative to create biopolymers with desired function or properties by taking advantage of the principle of natural evolution.
In the natural evolution of life, best one is selected from a lot of descendants. Evolutionary engineering mimics this evolutionary process to design novel proteins and nucleic acids. The technique consists of two steps: introduction of random mutations into a target gene to generate the variation, and selection of the mutated genes that express products with a desired property under selective pressure. Using the evolutionary engineering strategy, we can easily obtain biopolymers with desired function or properties even in the absence of information on the relationship among sequence, structure and function. Evolutionary engineering is also a powerful tool to elucidate the principle how the biopolymers are formed and express their functions.
Evolutionary engineering is also called as “Evolutionary molecular engineering”, “in vitro evolution”, or “directed evolution” because the technique direct proteins for evolve to the desired direction.