Muller and Mutations

by

Copyright © 2003-2004

[Posted: March 2, 2003]

The Quote

ermann Muller (1890-1967) is justly regarded as the father of radiation genetics. He is famous for showing that radiation can increase mutation rates, which he proved in 1926 with studies of fruit flies; work for which he eventually won a Nobel prize in 1946.

Muller is widely cited in the creationism/evolution debate, by both sides. One common quote, however, is both inaccurate and misleading.

The quote appears widely on creationist web sites in the following form:

It is entirely in line with the accidental nature of mutations that extensive tests have agreed in showing the vast majority of them detrimental to the organism in its job of surviving and reproducing, just as changes accidently introduced into any artificial mechanism are predominantly harmful to its useful operation . . Good ones are so rare that we can consider them all bad.

The last sentence is sometimes emphasized in bold face type or capitals. However, that sentence simply does not appear anywhere in the cited reference. The correct context is as follows:

It is entirely in line with the accidental nature of mutations that extensive tests have agreed in showing the vast majority of them detrimental to the organism in its job of surviving and reproducing, just as changes accidentally introduced into any artificial mechanism are predominantly harmful to its useful operation. According to the conception of evolution based on the studies of modern genetics, the whole organism has its basis in its genes. Of these there are thousands of different kinds, interacting with great nicety in the production and maintenance of the complicated organization of the given type of organism. Accordingly, by the mutation of one of these genes or another, in one way or another, any component structure or function, and in many cases combinations of these components, may become diversely altered. Yet in all except very rare cases the change will be disadvantageous, involving an impairment of function.

It is nevertheless to be inferred that all the superbly interadapted genes of any present-day organism arose through just this process of accidental natural mutation. This could take place only because of the Darwinian principle of natural selection, applying to the genes. That is, on the rare occasions when an accidental mutation did happen to effect an advantageous change, the resultant individual, just because it was aided by that mutation, tended to multiply more than the others.

The additional sentence added to the quote by creationists is a direct conflict with Muller's own words, which make explicit reference to rare occasions when an advantageous mutation occurs, and goes on to explain that accumulation of these rare advantageous mutations leads to the superbly interadapted genes of the present day.

Muller believed that that the rare but non-zero occurrence of advantageous mutations was a necessary consequence of the effects of Darwinian selection.

If the mutations were really non-teleological, with no relation between type of environment and type of change, and above all no adaptive relation, and if they were of as numerous types as the theory of natural selection would demand, then the great majority of the changes should be harmful in their effects, just as any alterations made blindly in a complicated apparatus are usually detrimental to its proper functioning, and many of the larger changes should even be totally incompatible with the functioning of the whole, or, as we say, lethal. That is, strange as it may seem at first sight, we should expect most mutations to be disadvantageous if the theory of natural selection is correct. We should also expect these mainly disadvantageous changes to be highly diversified in their genetic basis.

Muller on the risks of radiation exposure

The additional sentence added to the extract is not merely an invention, however. It appears in an unrelated non-technical article from Time magazine, in Nov 11 1946, just after Muller had received the Nobel prize.

When the Atomic Age really gets rolling, with atomic power plants producing much of the world's energy, the "level of radiation" will rise. People living near the plants will get more gamma rays through their gonads. So will people further away, affected by radioactive by-products from the plants' exhausts. Possible result: more redheaded children will be born in black-haired families, and more mutations will lurk in the germ plasm to scandalize future neighbors.

Whether this will be good or bad is not at all clear. In Washington last week, small, blue-eyed Dr. Muller, glowing with the stimulation of his newly won Nobel Prize, gave a pessimistic interview. "Most mutations are bad," said he. "In fact, good ones are so rare that we can consider them all as bad." It would be "fortunate," he thought, if all those exposed to an atomic explosion (such as the people of Hiroshima) were to be made permanently sterile.

Muller was more than an outstanding scientist; he was an outspoken and controversial one as well. He was something of a contradiction, both a humanitarian and a eugenicist.

In the article from Time magazine, Muller is taking up one of his humanitarian concerns, being the risks of the radiation in the nuclear age.

Muller's discovery of radiation induced mutation inspired a strange reaction in the popular mind. Mutation was seized upon as a plausible vehicle for accelerated evolution and origins of new abilities; or horrible monsters well able to defend themselves and wreak destruction on the rest of us.

In the extract from Time magazine, Muller is explaining that mutations are not a way of gaining wonderful new abilities; but that increased mutation rates are invariably very bad for you, which is quite true. The article is about fifteen months after the atomic bombing of Nagasaki and Hiroshima.

Muller advocated a naive kind of positive genetics. He was concerned that a combination of increased radiation levels and better health care would tend to foster a dangerous build up of disadvantageous mutations in humanity. His proposed solution was the use of "germinal repositories" to preserve the sperm of healthy and distinguished men. [ Plotz] On the other hand, he was also very critical of the American eugenics movement and of "applied genetics". [ Micklos]

Mutations since Muller's time

Muller's ground breaking work was performed long ago, even before the structure of DNA was known. He identified mutations mainly by the observed effect on an organism, and by a technique of chromosome marking, which is discussed briefly in his Nobel lecture.[ Nobel] At that time it was not possible to make direct examination of a DNA sequence.

We now know that technically, Muller was incorrect. By far the greatest number of mutations have little to no effect at all.[ Drake] Most mutations are "silent" and do not result in any change to the expression of the genome, and most of those which are expressed have effects which are too small to be detected against the normal variation seen in organisms due to recombination of parental genetic information and variety arising in the contingencies of development and growth. On the other hand, Muller is certainly correct that disadvantageous mutations are much more common than advantageous mutations, and that this should be expected given the effects of selection.

Muller on evolution

A special irony with the use of Muller to mount a criticism of evolutionary theory is that Muller himself considered evolution to be a fact.

When we say a thing is a fact, then, we only mean that its probability is an extremely high one: so high that we are not bothered by doubt about it and are ready to act accordingly. Now in this use of the term fact, the only proper one, evolution is a fact. For the evidence in favor of it is as voluminous, diverse, and convincing as in the case of any other well established fact of science concerning the existence of things that cannot be directly seen, such as atoms, neutrons, or solar gravitation.

Conclusion

This misquote illustrates some general principles on the matter of quotations.

• Most quotes taken from a very old source turn out to be taken second hand from a more recent publication that only gives selected extracts and no context. The proper thing to do in such a case is to cite both the original primary reference, and also the secondary reference used to obtain the text.
  
  
• Quotes that are fifty years old tend to be a bit out of date.
  
  
• Quotes which imply or suggest skepticism on evolution, but which are attributed to illustrious scientists who are active in research relating to evolution, are invariably misrepresentations of the actual opinions of the cited authority. There is a kind of cottage industry in these misleading quotes, and a special skepticism in warranted in these cases.

For a comprehensive examination of the phenomenon of quotation as argument, see the Quotations and Misquotations FAQ.

References

Acknowledgments

The administrator of an Internet Infidels Discussion Forum tracked down material on this quotation, and posted clarifications which were the seed of this FAQ. Tim Gamble cleaned it up and brought the matter to talk.origins. Chris Ho-Stuart added further background and generated the faq in its present form. The text of old extracts was checked by various talk.origins posters, especially Michael Hopkins and TomS.

Home Page | Browse | Search | Feedback | Links

The FAQ | Must-Read Files | Index | Creationism | Evolution | Age of the Earth | Flood Geology | Catastrophism | Debates