In religious thermodynamics, genetic entropy is a term defined in 2005 by American plant genetics researcher John Sanford as the mutational entropy affects within large genomes that cannot be reversed by natural selection. [1] This, according to Sanford, makes the eventual extinction of such genomes inevitable. Due to the religious undertones used in Sanford's book, the term has since been taken up by the intelligent design and creation science movement.

The term "genetic entropy" to note, in a loose sense, was previously used by authors V. K. Savchennko and U. K. Sauchanka in 1997 in association with their concept of gentropy. [2]

References
1. Sanford, J.C. (2005). Genetic Entropy and the Mystery of the Genome - the Genome is Degenerating, (pg. 144). Lima, New York: Ivan Press.
2. Savchennko, V. K. and Sauchanka, U. K. (1997). The Genosphere: the Genetic System of the Biosphere, (pg. 4, pgs. 41-42). Informa Healthcare.