Gene

A gene is a genetic replicator, a basic unit of heredity in a living organism, and a segment of DNA that is involved in producing proteins. Genes shape life-forms, they are blueprints for biological bodies and recipes for stringing together amino acids into proteins.

Genes are not the only form of replicators, and biological evolution is not the only form of evolution. There are also memes in analogy with genes, and there is also cultural and cosmic evolution.