1953 · James Watson and Francis Crick
Molecular Structure of Nucleic Acids
What this work is
A one-page letter to Nature, April 1953, proposing a structure for DNA. Two chains wind round one axis, with the sugar-phosphate backbones outside and the bases paired inside by hydrogen bonds: adenine with thymine, guanine with cytosine. It ran in the same issue as the X-ray papers from King's College London.
Then and now
Watson and Crick fitted a two-chain model to other labs' X-ray smears and equal chemical ratios, and said the model must be regarded as unproved. The copying idea was a passing remark, never checked. Genomics now cites the paper as the founding proof of DNA as a code carrying heredity, which nobody has seen.
Verdict
UNSCIENTIFIC
Neither the paradigm nor the work inside it passes. The verdict is unscientific.
1·This work · inside the paradigm
UNSCIENTIFIC
Does not follow the scientific method within Genomics / DNA Model.
2·Paradigm · Genomics / DNA Model
UNSCIENTIFIC
Fails the tests. The worse layer decides.
How the verdict is decided
The verdict grades both layers: the paradigm this work assumes, and how the work was carried out inside it. Both must be scientific for the whole thing to be scientific. A clean method inside an unscientific paradigm is unscientific. An unscientific method inside a better paradigm is unscientific. A split on either layer is mixed. The worse layer decides.
1·This work
Did this work test its claim with methods that are independent, falsifiable, and non-circular?
UNSCIENTIFIC
This study claims that DNA is two spiral chains wound around each other, held together by paired building blocks, and that this pairing suggests how the genetic material is copied. All three tests fail.
Independently Verifiable
Fail
The only things anyone recorded were smears on film and chemical ratios, and the double spiral exists only as the authors' drawing of what those smears mean.
Falsifiable
Fail
The authors say their structure is only roughly compatible with the data and must be regarded as unproved, so no result in the paper could have killed it.
Non-Circular
Fail
They built the structure to fit the equal-amount ratios, then offered that same fit as support for the pairing and the copying idea.
Why
The authors never touched a spiral. They had X-ray smears from other labs, published chemical ratios, and cardboard-style model pieces built to fit. They state the earlier X-ray data are "insufficient for a rigorous test," that the model is "roughly compatible" with them, and that it "must be regarded as unproved." They assumed the usual chemistry and the most plausible forms of the building blocks, then found that only certain pairs fit. The equal-amount ratios were the starting constraint, so their reappearance in the model is not a test. The copying mechanism is a suggestion they say has "not escaped our notice." It was never checked. No one saw a pair, a chain, or a code.
2·Paradigm · Genomics / DNA Model
Does the framework this work assumes pass the three tests?
UNSCIENTIFIC
Independently Verifiable
Fail
The field's central entity, a molecule carrying a readable code in the living cell, is only ever seen as signals from machines and chemistry that the model reads as that molecule.
Falsifiable
Fail
When a cut or edit fails to produce the predicted trait, the field blames the design of the tool, or calls the trait complex, and never the model.
Non-Circular
Fail
Sequencing readouts, reference maps, and gene-editing tools were all built from the code model and are then used to confirm that code model.
Why
The DNA model is judged here on its own entities. A purified fibre gives film smears and a precipitate. That the substance sits inside living cells as a code is the model's claim. The tools that followed, sequencers, probes, reference maps, and editing guides, were built from the double-spiral and code idea and then used to confirm it. When predictions fail, the field says missing heritability, complex trait, or poor guide design. The model has never been put at risk. Working products do not ground the code. They show a procedure produced an output.
From the work
The previously published X-ray data on deoxyribose nucleic acid are insufficient for a rigorous test of our structure.
So far as we can tell, it is roughly compatible with the experimental data, but it must be regarded as unproved until it has been checked against more exact results.
It has not escaped our notice that the specific pairing we have postulated immediately suggests a possible copying mechanism for the genetic material.
If it is assumed that the bases only occur in the structure in the most plausible tautomeric forms (that is, with the keto rather than the enol configurations) it is found that only specific pairs of bases can bond together.