Aspects of genetics including mutation, hybridisation, cloning, genetic engineering, and eugenics have appeared in fiction since the 19th century.

Genetics is a young science, having started in 1900 with the rediscovery of Gregor Mendel's study on the inheritance of traits in pea plants. During the 20th century it developed to create new sciences and technologies including molecular biology, DNA sequencing, cloning, and genetic engineering. The ethical implications were brought into focus with the eugenics movement.

Since then, many science fiction novels and films have used aspects of genetics as plot devices, often taking one of two routes: a genetic accident with disastrous consequences; or, the feasibility and desirability of a planned genetic alteration. The treatment of science in these stories has been uneven and often unrealistic. The film Gattaca did attempt to portray science accurately but was criticised by scientists.

Modern genetics began with the work of the monk Gregor Mendel in the 19th century, on the inheritance of traits in pea plants. Mendel found that visible traits, such as whether peas were round or wrinkled, were inherited discretely, rather than by blending the attributes of the two parents. In 1900, Hugo de Vries and other scientists rediscovered Mendel's research; William Bateson coined the term "genetics" for the new science, which soon investigated a wide range of phenomena including mutation (inherited changes caused by damage to the genetic material), genetic linkage (when some traits are to some extent inherited together), and hybridisation (crosses of different species).

Eugenics, the production of better human beings by selective breeding, was named and advocated by Charles Darwin's cousin, the scientist Francis Galton, in 1883. It had both a positive aspect, the breeding of more children with high intelligence and good health; and a negative aspect, aiming to suppress "race degeneration" by preventing supposedly "defective" families with attributes such as profligacy, laziness, immoral behaviour and a tendency to criminality from having children.

Molecular biology, the interactions and regulation of genetic materials, began with the identification in 1944 of DNA as the main genetic material; the genetic code and the double helix structure of DNA was determined by James Watson and Francis Crick in 1953. DNA sequencing, the identification of an exact sequence of genetic information in an organism, was developed in 1977 by Frederick Sanger.

Genetic engineering, the modification of the genetic material of a live organism, became possible in 1972 when Paul Berg created the first recombinant DNA molecules (artificially assembled genetic material) using viruses.

Cloning, the production of genetically identical organisms from some chosen starting point, was shown to be practicable in a mammal with the creation of Dolly the sheep from an ordinary body cell in 1996 at the Roslin Institute.