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February 23, 2015

A Prohibited Animal

According to Karl R. Popper, in comparing two competing theories, the one that forbids more occurrences in the natural world—that lists more possible refutations—is superior to one that forbids fewer. (1)

In Chapter Thirteen of Cancer Selection I describe three separate and distinct refutations of my proposed fundamental amendment to the neo-Darwinian theory of evolution. In one refutation I describe an imaginary animal, one that possesses a constellation of particular characteristics, each one of which can be found in abundance in Nature, and assert that such an animal cannot exist; find one forbidden specimen and my theory is refuted.

My prohibited animal is not narrowly defined. It could be marine, terrestrial or amphibian. It could subsist on any imaginable diet. It could be predator or prey. It could breed, raise its young, move about and generally behave in any way imaginable. But it must possess—or it must not possess—the following specific characteristics:

This animal must:

Weigh at least one kilogram at maturity.

Remain a juvenile for at least six months.

Consist, at maturity, of at least thirty different kinds of cells.

Have a central nervous system, including a brain.

Possess a circulatory system complete with a heart.

But it must not:

Have non-cellular outer covering, or pigmentation in its exposed cells; its external flesh must be soft, hairless and transparent.

Array masses of post-mitotic cells so that they shield dividing cells from extra-terrestrial radiation.

Possess the ability to destroy routinely cells already transformed to the cancer state.

Severely limit mitosis. Eutely is prohibited as is the predominance, as in modern insects, of post-mitotic cells throughout the soma .

Finally, to eliminate habitat selection or daily vertical migration as a means of minimizing exposure to extra-terrestrial carcinogenic radiation, this creature must:

Be exposed to direct sunlight for at least eight hours a day while a juvenile and as an adult.


One possible reaction to this proposed refutation might read like this: "The possibility of refutation means your theory meets a criterion for considering it 'scientific,' not that it is correct. All you are doing is presenting evidence that the complex animals, all the Bilatertians, prominently display characteristics that could have protected them from cancer and that colonial animals, the Cnidaria and Porifera, do not. At best you will convince us that complex animals experienced, over evolutionary time, lots of lethal juvenile cancer and the colonials did not. Yet you claim your idea is a fundamental and necessary amendment to evolutionary theory when all it does is say something about the likely occurrence of juvenile lethal cancer in the past. Even if you are correct, your idea is of minor interest to evolutionary biologists."   

Such a reaction has no validity. It means the commentator profoundly misapprehends my theory. It's an opinion that requires one to ignore, as I write in the opening paragraph of my peer-reviewed Journal of Theoretical Biology 1983 Letter that " ... all selected defenses against cancer would have enhanced the ability of the genomes to create organisms in which the genetic program is expressed with great fidelity in all somatic cells."

Anyone who refuses to accept that claim, which is the core of my theory and the basis for my insistence that it constitutes an absolutely essential revision to conventional neo-Darwinism has an obligation to either point to a flaw in its logic or identify physical phenomena that refute it. As for potential refutation, I wrote in Chapter Thirteen as the first of three refutations: describe a morphophysiological character or mechanism in any juvenile Bilaterian that would protect it from cancer death but that would not also—despite the "carcinogens are mutagens" conclusion reached by Ames et al (2)—enhance precise expression of the development program in individual somatic cells.

Serious critics refute theories. Un-serious critics claim that they understand the theory and its author does not. 


1. "... if the class of potential falsifiers of one theory is 'larger' than that of another, there will be more opportunities for the first theory to be refuted by experience; thus compared with the second theory, the first theory is said to be 'falsifiable in a larger degree.' This also means that the first theory says more about the world of experience than the second theory, for it rules out a larger class of basic statements. ... Thus it can be said that the amount of empirical information conveyed by a theory, or its empirical content, increases with the degree of its falsifiability. "The Logic of Scientific Discovery" Harper Torchbooks, New York, 1959. (pp112-113). 

2. Ames BN, Durston WE, Yamasaki E, Lee FD. Carcinogens are mutagens: a simple test system combining liver homogenates for activation and bacteria for detection. Proc Natl Acad Sci U S A. 1973 Aug;70(8):2281–2285.

Comments and questions to the author ... are welcomed here.

At this site you will find links to additional material including my original Letters to the Journal of Theoretical Biology and  the 1992 Nature review of my book.

Copyright © 2015 by James Graham

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