Concept

Genetic Entropy

Intro

John Sanford was a Cornell geneticist who helped invent the gene gun, a tool widely used in agricultural genetic engineering. He spent his career inside mainstream science. Then, after re-examining his evolutionary assumptions, he wrote Genetic Entropy and the Mystery of the Genome (2005) and argued that the human genome is decaying, not improving, and that this decay is incompatible with the deep timescales evolution requires.

The argument has four steps. First, humans pick up dozens of new mutations every generation. Second, almost all those mutations are slightly harmful; helpful ones are rare. Third, natural selection cannot catch mutations whose harmful effect is below a certain size; they slip through. Fourth, over many generations, the harmful mutations pile up faster than they can be removed. The genome runs down, like a battery that loses a little charge every cycle.

If Sanford is right, complex genomes cannot be millions of years old. They would have already collapsed. He concludes that human and other genomes are young, on the order of thousands to tens of thousands of years, and that this is evidence for a recent creation and for the limits of universal common descent.

Mainstream evolutionary genetics disagrees, mostly for three reasons: purifying selection is more powerful than Sanford models, recombination breaks up linked mutations, and the simulation tool he uses (Mendel's Accountant) has been criticized for its parameter choices. The page lays out Sanford's argument in full, then the mainstream responses, then the back-and-forth. It does not pick a winner; the science is still actively contested.

In full

A population-genetics argument advanced by John C. Sanford (former Cornell geneticist, contributor to the development of the gene gun) in Genetic Entropy and the Mystery of the Genome (2005, Ivan Press; 4th ed. 2014). The thesis: because the overwhelming majority of new mutations are slightly deleterious, and because natural selection is unable to filter them out below a certain effect size (Kimura's "near-neutral" zone), mutations accumulate over generations and the genome erodes, a process Sanford calls genetic entropy. The implication: human and other complex genomes cannot be billions of years old, and the deep timescales required for universal common descent are inconsistent with observed mutation rates.

Core claim

Sanford's argument has four steps:

Mutation rate. Humans accumulate ~60-100+ new germ-line mutations per generation (mainstream estimates).
Mutation distribution. The vast majority of mutations are slightly deleterious; beneficial mutations are vanishingly rare.
Selection limits. Natural selection cannot filter mutations below a certain fitness-effect threshold (Kimura's near-neutral zone). Slightly deleterious mutations therefore drift to fixation despite being marginally harmful.
Genome decay. Over many generations, the accumulated load erodes genome integrity. A human genome cannot remain viable on this trajectory for the timescales (millions of generations) required by universal-common-descent models.

Conclusion: complex genomes are young, on the order of thousands to tens of thousands of years rather than millions; the deep timescales demanded by universal common descent are incompatible with observed mutation-load dynamics.

Mendel's Accountant

To test the argument quantitatively, Sanford and collaborators (John Baumgardner, Wesley Brewer, others) developed Mendel's Accountant, a forward-time numerical simulation of population genetics that explicitly tracks deleterious mutations across generations under user-specified selection regimes. Sanford reports that under realistic parameter choices the simulations consistently show fitness decline rather than stability, supporting the entropy thesis. Mendel's Accountant has been published in peer-reviewed venues (the Scalable Computing journal, IEEE conference proceedings).

Major proponents and works

John C. Sanford, Genetic Entropy and the Mystery of the Genome (2005, 2014); Contested Bones (2017, with Christopher Rupe); founder/director of FMS Foundation; previously professor at Cornell University.
John R. Baumgardner, geophysicist (formerly Los Alamos); collaborator on Mendel's Accountant; YEC global-flood modeler.
Wesley Brewer, Walter ReMine, Robert Carter, co-developers / proponents.
John Sanford and Robert Carter, joint work on the Out-of-Africa human migration model from a creationist perspective.

Mainstream-science engagement

Genetic entropy is rejected by mainstream evolutionary genetics. The principal responses:

1. Purifying selection is more powerful than Sanford allows

Mainstream population genetics holds that purifying selection (the selective removal of deleterious alleles) is highly efficient at maintaining genome integrity over evolutionary time. Most slightly deleterious mutations occur in non-functional regions of the genome and have negligible fitness impact; those in functional regions are filtered out by selection. The mutational load that genetic entropy posits as accumulating is held to be illusory.

2. Beneficial mutation rates are higher than Sanford allows

The fraction of beneficial mutations is small but non-zero; given large population sizes and long timescales, the supply of beneficial mutations is sufficient to offset the accumulation of slightly deleterious ones. Population-genetics models (Eyre-Walker & Keightley 2007; Nature Reviews Genetics literature) accommodate this balance.

3. Mendel's Accountant has been critiqued for parameter choices

Critics (notably PZ Myers; biologists at Panda's Thumb) argue that Mendel's Accountant's results are highly sensitive to parameter assumptions, and that Sanford's chosen parameters skew toward decline. Defenders respond that the parameters used are well-supported by mainstream estimates.

4. Empirical observation

Long-term laboratory evolution experiments (Lenski's E. coli long-term evolution experiment, ~75,000 generations and counting) and natural-population studies do not show the genome-wide decay predicted by genetic entropy. Bacteria, with high mutation rates and long evolutionary histories, do not appear to be undergoing meltdown. (Defenders of genetic entropy reply that Lenski's experiment shows substantial degradative change and very limited constructive change, see Behe's Darwin Devolves, but this is a different argument.)

Apologetic / theological deployment

Genetic entropy is one of Sanford's principal contributions to the YEC apologetic toolkit and is widely cited in YEC literature and Answers in Genesis material. It is deployed:

As positive evidence for a young human genome (a few thousand to tens of thousands of years from a mitochondrial Eve / Y-chromosomal Adam)
As a negative argument against universal common descent: the deep timescales and large effective population sizes the model requires are inconsistent with mutation-load dynamics
As a theological resonance: the genome is running down, consistent with a post-Fall world (Romans 8:20-22, "creation was subjected to futility... the bondage to corruption") rather than with a Darwinian world of progressive complexification

The argument also intersects with the YEC use of mitochondrial-DNA mutation rates (Parsons et al. 1997) and Y-chromosomal coalescence times to argue for a recent human ancestor consistent with biblical chronology.

Critiques and responses

From mainstream evolutionary biology

Selection is more efficient than the model assumes. This is the central technical objection.
The model conflates deleterious mutations in non-functional regions with deleterious mutations in functional regions. Most of the genome is non-coding; mutations there are largely neutral.
Long-term empirical studies (Lenski) do not show the predicted decline.
Mendel's Accountant has not survived peer-review scrutiny outside YEC venues.

From inside the design-inference camp

Sanford's argument is broadly accepted in YEC and ID-friendly circles; some ID-friendly biologists (Behe in Darwin Devolves) endorse the broader thesis that observed evolution is overwhelmingly degradative.
Some are more cautious about the specific Mendel's Accountant parameter choices.

From theistic evolution

The argument is held to misrepresent the technical literature on mutational load (Eyre-Walker, Charlesworth, Keightley) and to over-rely on simulations whose assumptions can be challenged.