The Case of the Living Fossil

"Scientific" creationists are fond of easy examples that seem to contradict evolution: so much the better if they seem to make scientists look silly.

An example that pops up from time to time is a living fresh-water mollusc that radiocarbon dating seemed to show was 2300 years old.

This intrigued me: were the scientists who got that result so incompetent that they didn't notice it? In that case, their technique was probably faulty, too, and there was nothing to explain.

Or were they corrupt and did they try to conceal the absurd result? Why did they fail?

I was very pleased to see that Duane Gish—in a peculiar booklet allegedly written by him but featuring many pictures of him lecturing to an enthralled audience* — actually gave a reference for this claim: Kieth [Keith] and Anderson, in Science, Vol 141, 16 August 1963, pp634-6.

I obtained a copy of the paper, and the answer to my questions is that the scientists were neither knaves nor fools: the result was obtained straightforwardly, and reported clearly:

"Radiocarbon Dating: Fictitious Results with Mollusk Shells

Abstract. Evidence is presented to show that modern mollusk shells from rivers can have anomalous radiocarbon ages, owing mainly to incorporation of inactive (carbon-14-deficient) carbon from humus, probably through the food web, as well as by the pathway of carbon dioxide from humus decay. The resultant effect, in addition to the variable contributions of atmospheric carbon dioxide, fermentative carbon dioxide from bottom muds, and locally, of carbonate carbon from dissolving limestones, makes the initial carbon-14 activity of ancient fresh-water shell indeterminate, but within limits. Consequent errors of shell radio carbon dates may be as large as several thousand years for river shells."

Accurate dates can readily be obtained from wood: a continuous series of tree-rings has been made for the last 3000 years, by matching rings from different trees. It is by comparison with the C!4 from these that the freshwater shellfish were shown to be anomalous, by earlier workers. Keith and Anderson's paper merely investigates the reason for this anomaly, and proposes one mechanism—that the living molluscs had eaten carbon that had been taken out of circulation long before, instead of recently. They conclude:

"It follows that the initial C!4 content of shell specimens and other organic materials originating in rivers and lakes cannot be exactly known or assumed. ... The large and variable effects due to dilution of modern carbon with inactive carbon from the humus and limestone reservoirs will remain indeterminate. Resultant errors in radiocarbon age may be as much as 3000 years for shell samples from rivers and several hundred years for lacustrine [lake] and marine shell samples.

Maximum error is to be expected in shell specimens from animals which lived in humus-laden streams which were actively cutting into old flood plains or old soil profiles."

In other words, this small paper reports on a source of error in radiocarbon dating for a particular group of organisms in a particular habitat, and warns against being led astray by it.

For Gish to present this as evidence that radiocarbon dating is an unreliable method which fools people into believing evolution, is peculiar, to say the least.

It is less so if one regards creationists not as practising science, but as promoting religion. It is in harmony with a mind-set that I call "authoritarian" to suppose that experiments should yield crisp and exact results, with which there may be no dispute, and in this case, that radiocarbon dating should easily yield an accurate (and exact?) age for any material.

• I've lost the name of that booklet, but another in the same format deserves a note of its own: "Big Daddy?" by Jack T Chick, published in 1972 by Chick Publications (P O Bex 662, Chinc, CA 91710) puis it this way: "A living mollusk was tested by carbon-14 and found to be dead for 3000 years! [footnote:] Creation Research Society Journal June 1970" (And what's 700 years between friends?)

In "Big Daddy?" a stereotypically-Jewish-looking evolution lecturer, supported by a class of dirty, hippie-type students, browbeats a handsome, clean-cut, blond, male, Christian student—until our hero wins them all over. Here are the first four frames: "How many of you believe in evolution?" "WE DO SIR!" "Anyone disagree?" "I do Sir!" "You can GET OUT of my class!! After you've apologized to everyone for your rudeness and ignorance we might let you back in!" (Weren't your biology lecturers all just like that?)

We learn that "it's common knowledge!" that science has produced life in the laboratory (until the h. c-c. b. m. C. s. demolishes that in the next frame) but what most astounded me was the revelation that God is the strong nuclear force!

"What" asks the student, "is the binding force of the atom?" The biology lecturer admits his ignorance, and the student tells him "the Bible...says that Christ, the Creator, 'was before all things, and by him all things are held together' Col. 1:17."

Does this mean, I hear you cry, that God came into existence 10°35 seconds after the Big Bang? Probably not. Hearsay stories about cases like this pass into the folklore, they get bandied about and distorted—especially by people who have an interest in the distorted versions—and it's usually impossible to find the original source. This was a pleasing exception.