Molecular Evolution Activities

Documents on Molecular Evolution


Online Document


Thomas Jukes, "Some Comments on the Newspaper Article "Scientists in War Over "Neutral Theory of Genetics" by Deborah Blum, Sacramento Bee, p. 1, March 16, 1992" Unpublished Manuscript, March 19, 1992.


About two weeks ago, I had a call from the author who had been given my name by Will Provine. She said she had spent two hours with John Gillespie in Davis, which is, of course, the fortress of anti-neutralism started by Ledyard Stebbins, who brought staunch anti-neutralists T. Dobzhansky and F. Ayala to Davis. The tradition is maintained by Gillespie.

I chatted with Blum about the neutral theory and sent her "Non-Darwinian Evolution," by King and Jukes (1969) and "Early development of the neutral theory" (Perspectives in Biology and Medicine, 34, 473-485:1991) by me. I see no indication that she read either of them, but instead relied on phone conversations, except for her visit to Gillespie, whose picture is in the article.

The headline starts the article with an error. The neutral theory is of (molecular) evolution, not genetics, but genetics is an easier word to understand. As one should expect, the motive for a reporter is to sell newspapers, not review science, and the article is quite sensational. Here are some comments:

"researchers have started shouting at each other during cocktail parties" Evidence?

"If Jukes and King began the fight in this country, the most powerful proponent of the neutral theory on the international scene was Matoo [sic]


Kimura, director of Japan's National Institute of Genetics. Kimura began publishing on the theory in 1968. He has worked tirelessly on its behalf since, and he considers it his own.

"I published one year before Jukes did," he said in a telephone interview.

Comment: Science is international. The "fight" over our article started in England (Clarke, Nature). Kimura may consider the neutral theory "his own," but there are different opinions. He did not publish "one year before Jukes did." I published an outline in Molecules and Evolution (book) 1966. See my review, cited above.

"In years John [Gillespie] almost single-handedly carried the banner for natural selection" says Martin Kreitman.

Erroneous. Natural selection is accepted by all evolutionists, including neutralists.

The theory predicts that genetic drift will occur at a steady rate, so constant that by measuring DNA differences between two species, one can calculate how long ago they separated on the evolutionary tree. For instance, based on the tiny variation between humans and chimpanzees, scientists believe the two species separated about 5 million years ago.


That steady tick of variation is known as the "molecular clock." ~

An excellent statement, but see the final paragraph, alleging that I don't concede it. (wrong)

"But Gillespie says that new technology--allowing better pictures of proteins and genetic material--has shown clearly that the variation is not steady, that there are sudden rapid bursts of change. The neutral theory fails to allow, as Gillespie does in his work, for some real complications, such as a changing environment.

Dick Holmquist and I were the first to draw attention to the fact that variation is not steady. See "Evolutionary clock nonconstancy of rate in different species" Science 177, 530 (1972).

"The people who introduced it have fallen in love with their own beautiful math" Ayala said. "They've forgotten that it isn't necessarily reality."

Ayala has forgotten that the neutral theory is based on reality, not math. King and Jukes (1996) used no math. My 1966 outline was based on the simplistic statement that "the changes produced in proteins by mutations will in some cases destroy their essential functions but in other cases the change allows the protein molecule to continue to serve its purpose."

(Ayala) "The molecular clock concept should still hold. The time spans . . . are so huge that a little wobble doesn't mean that much." Neither Jukes nor Kimura concedes even that much."

Incorrect. I have drawn attention to this point: J. Mol. Evol. 20 87-98, 1987. I said, "The molecular evolutionary clock tends to persist, despite great variations in its rate of keeping time."

Summary: Gillespie emerges from this article as a hero who has been mistreated by an intolerant and belligerent Kimura. Kimura's hostility is said to be based on a cultural difference ("In Japanese society, that's very insulting"). The article contains a number of errors, as listed above, some by its author and others occurring in the quotations she has reported in interviews. The people she interviewed, of course, may have been misquoted. The concluding paragraph in King and Jukes is recommended as an exposition of the neutral theory.

From these considerations it is not difficult to conclude that the stream of spontaneous alterations in DNA, continuously fed into the genetic pool, should include far more acceptable changes that are neutral than changes that are adaptive. Protein molecules are subjected to incessant probing as a result of point mutation and other DNA alterations. The genome becomes virtually saturated with such changes as are not thrown off through natural selection. We conclude that most proteins contain regions where substitutions of many amino acids can be made without producing appreciable changes in protein function. The principal evidence for this is the astounding variability in primary structure of homologous proteins from various species, and the rapid rate at which molecular changes accumulate in evolution.

No mention is made in the article of James Crow, Noboru Sueoka, and Ernst Freese, who helped found the neutral theory, although this was explained in Jukes 1991).


March 19, 1992




This page was written by Michael Dietrich. It was last updated on May 16, 2004.