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How to lie about radiometric dating, evolution, and even nuclear physics

Have you heard the one about the live snail with a carbon-14 age of 3000 years? Or the lava erupted in 1800 in Hawaii with a potassium-argon age in the millions? It’s all true, true I tell you. But does this signify a major problem with radiometric dating?

Spoiler: no.

I don’t know who first dug up these examples, but they were popularised by the creationist comic-book writer Jack Chick, in a publication called “Big Daddy”. The first page, available here if you’re lucky (the links to Chick Publications only seem to work at random), shows a well-primed creationist student arguing with a singularly ill-informed biology professor. The professor has been leading such a sheltered life that he’s never met these creationist arguments before. And he doesn’t understand anything about evolution or dating of rocks or embryology or indeed anything else. Surprise! the student wins! A skilled cartoonist, Jack Chick manages to squeeze the largest number of fallacies into the smallest number of words. There is a crib sheet at the end of this post, listing all the fallacies I spotted myself; I just reached double figures but there may be more.

Evoa

dating

gillarch

vestigial

Of course, it doesn’t help that the Professor doesn’t know anything about whale ancestors:

WhaleAncestors

Or that the student is allowed to make the most absurd statements unchallenged, on the basis of a video by Kent Hovind:

evoc

But there’s more! At the end of page 1, which is also the end of your free sample I’m afraid, the student converts the Professor by pointing out that no one has ever actually seen gluons:

Gluons

Gluons2

But fear not; an answer is at hand, in the very next frame:

Gluons3
So Jesus must be the force that holds the atomic nucleus together. Convinced by this reasoning, the Professor accepts Jesus, announces that as a result he can no longer teach evolution, and is sacked.

Jack Chick, by the way, has just published another comic book at the age of 92. In it, a bright young man from a good Christian (i.e. creationist) home is seduced by Satan into believing in evolution, and when we last see him is heading straight for damnation. In the words of one of Satan’s many horned helpers, “Joe trusted evolution, not God, and became a jobless party animal.” And a criminal and a drug addict, and covered himself with tattoos, and died and went to hell. Tragic, and so easily avoidable.

I never managed to get to Page 13 of Big Daddy, which is what we really need; link (if it works for you) here. It didn’t work for me, but you’ll find a description of the contents by someone called Honus at talkorigins, and I’ve seen some of the relevant cartoons reproduced elsewhere. So you can either take Honus’s and my word for it, or go online to Chick Publications and buy 25 copies (minimum purchase) of the tract, which I am not about to do.

The really remarkable thing about the tract is that it actually gives the primary literature references to the results that is discussing. And the briefest perusal of this primary literature will show why the papers that Chick refers to, far from undermining radiometric dating, actually reinforce it.

That snail was not 3000 years old, but that really was its apparent radiocarbon age, because it was exchanging calcium carbonate in its shell with mineral calcium carbonate. And that makes all the difference, so you need to take such features of the environment into account.

Many readers will be familiar with the principle of carbon-14 dating. Carbon-14 decays with a half-life of 5730 years. Nonetheless, the fraction of carbon-14 in the atmosphere stays roughly constant (or did before we started adding to it by nuclear weapons testing, and diluting it with carbon dioxide from fossil fuels). That is because the upper atmosphere is bombarded with cosmic rays, which cause nuclear reactions that convert nitrogen-14 (stable) to carbon-14. Mixing distributes this radiocarbon through the atmosphere, where it is taken up by plants and, in due course, animals. As long as you are alive, you are part of the circulating pool of carbon, but as soon as you die, the carbon-14 in your body starts decaying. Of course, cosmic ray intensity is not really constant over a long period, but we can calibrate carbon-14 dates by comparison with carbon in tree rings (dendrochronology). The tree ring correction is small for most purposes, but matters for things like precise dating of Egyptian dynasties.

The point, of course, is that the carbon in the lettuce being fed to the snails is part of the general pool, but the carbon in calcium carbonate minerals is radiochemically dead, having been out of circulation for a long time. What the paper really showed was that the snail exchanges carbonate in its shell with carbonate from dissolved minerals, giving a spurious depletion of radiocarbon in the snail. You will find the story in Science, 1963, p. 637 (paywall, sorry, but summary here).

What about these rocks in Hawaii? Here again the paper is behind a pay wall, but if you follow this link it will take you to the title and abstract, which is all you need. In fact, the title alone is all you need: “Radiogenic helium and argon in ultramafic inclusions from Hawaii”. Inclusions. And in case that’s not clear enough, the abstract tells you that the work is all about the dating of xenoliths. Xeno- foreign, as in xenophobia; lith rock, as in monolith. Look at the paper in more detail, if you can get access to it, and you will find that the excess argon is only found in bubbles of fluid within the rock, that bits of rock that aren’t bubbly don’t show any, and that there is circumstantial evidence that the argon comes from deep within the Earth’s mantle, not radioactive decay in the lava itself.

Anomalies happen all the time in geology. They are, in the original sense of the expression, exceptions that prove the rule; if there were no rule, we would not consider them exceptional. Uranium-lead and potassium-argon dates of rocks usually agree, but not if the rock has been so strongly heated that argon gas can escape. Whole rock dates can be misleading, as in the example of the Hawaiian volcano, if the rock has been contaminated from some source, in this case fluid from the mantle. So far from undermining the method, these anomalies add further information about the sample. In much the same way, radiocarbon dates will be anomalous if some of the carbon comes from inorganic sources, as in the case discussed above, and the anomaly might even be used to tell us something about the specimen’s history and diet.

Now here’s the bit that I really don’t understand. What is going on in Jack Chick’s mind, when he gives us this stuff? I assume that he is an honest person of goodwill, who is doing his best. He really believes that because I and most readers here accept the fact of evolution, we are going to be punished in hell for ever. Being a kindly man, he really doesn’t want that to happen, so he is doing his very best to convince us of the error of our ways.

So why does he do it by pointing us towards papers that say the very opposite of what he says they say? I can only speculate that this is the result of what psychologists call confirmation bias, which leads to interpreting new information, however perversely, in a way that supports what you already think. And when we come to creationism, the motivation for bias is extreme. Remember that we are talking about people who really believe (a) that if you don’t accept salvation through Jesus you are going to go to hell, and (b) that the doctrine of salvation through Jesus only makes sense if the biblical Fall is a historical fact. The papers I’ve mentioned above show that under certain rather special circumstances, radiometric dating will give you the wrong answer unless you take those circumstances into account. Young Earth creationists, knowing that their entire worldview depends on refuting radiometric dating, pounce on these examples as evidence that the method is unreliable. Which of course it is, if you don’t do it right. So what?

All of which gives me uncomfortable pause for two reasons. If creationists are so blinded by confirmation bias, what hope is there of reasoning with them? And if I see my intellectual opponents displaying confirmation bias, completely oblivious to what they are doing, what makes me think that I am any different?

h/t Sensuous Curmudgeon for tip-off about Jack Chick’s latest. Whale ancestors illustrated (Ambulocetus and Pakicetus) copyright JGM Thewissen; may be reproduced for non-commercial educational purposes.

IncredibleCrib sheet: Definition as obfuscation. Misdefinition of science to exclude all indirect inference (although even Young Earth creationists accept the fact of an Ice Age on geological evidence). Macroevolution, if the word means anything, means major change, and this takes more time than we have been watching. So of course we’ve never seen it. Similar fossils do indeed imply similar ages, but the order of these ages has been known for nearly 200 years on the basis of stratigraphy, and absolute ages established for over 100 years now by radiometric dating. Polystrate fossils were explained in 1868; the explanation is much the same today. New Scientist really did point out in 1997 that it is silly to carry on using Haeckel’s highly questionable drawings, as some still do, when we now have a much more detailed information. But, as explained in Alice Roberts’s Incredible Unlikeliness of Being and many other places, the gill folds on the human embryo really are homologous to the folds on that of a fish. They just develop rather differently, explaining such oddities as the tortuous path of our vagus nerves. As for the whale’s pelvis having “nothing to do with walking on land”, by 1999 we already had extensive series of fossils linking whales to their terrestrial ancestors; there is an excellent review here by one of the scientists involved in Evolution Education and Outreach (free download), and whales evolution also features in an excellent video here . The development of secondary functions (exaptation) is commonplace. Thus mammals’ ear bones are vestigial relics of reptiles’ rear jawbones. Creationists often argue, as here, that natural selection can only remove, and not add. This riddle was solved 120 years ago, with the discovery of mutation. Mutations supply novelty; selection winnows it. Creationists agree in explaining away pre-modern human fossils, such as Lucy and numerous others already known by 1999, as being either apes, or humans. Unfortunately, they can never agree on which is which. And, something that I think believers in particular should find offensive, the theological absurdities of the final frame.

Darwin vs today’s creationists; Eugenie Scott in Glasgow

GenieIntro

Lady Hope; Darwin on religion; varieties of creationism; creationist activity in UK; Petition 1530; Intelligent Design and the varieties of creationism; the eye; continental drift and biogeography; Mendelian inheritance; ancestry of whales; varieties of creationism; the “missing link”; Q&A

This is my personal selection from the talk that Genie gave to the Glasgow Skeptics on Monday February 15, as best I recall it. I thank her for a copy of her slides, and any misinterpretation is entirely my own fault (I have added some comments of my own in parentheses).

the title of the talk was: “What Would Darwin Say to Today’s Creationists?” The answer is just this:

Haven’t you been paying attention during the last 156 years?

Lady Hope and the myth of deathbed conversion

The first thing that would surprise Darwin if he could come back to life today would be the legend of his death-bed confession, to a certain Lady Hope, of reversion to Christianity and renunciation of evolution. Lady Hope is real enough. An evangelist and temperance crusader, she was a colleague of the philanthropist James Fegan, who ran a mission to London’s street urchins. Fegan corresponded with Darwin, who in 1880 gave him permission to use the reading room at Downe House for his work, and it seems plausible that Darwin and Lady Hope might have met around then.

In 1915, we have Lady Hope being reported at a Baptist revival meeting as having said that she spoke with Darwin in his death bed, and that Darwin had confessed to a love of scripture, and to regretting things he had said when younger. More specifically, that as a young man with unformed ideas he had thrown out suggestions that to his surprise spread like wildfire. (I note that Darwin in his autobiography confessed to an initial love of Paley’s natural theology, and in The Descent of Man to surprise at the speed with which evolution had been accepted, and remarks of this kind may be the seed of Lady Hope’s account.) In 1915, Lady Hope was over 70, so knowing how memories are reworked, and how stories grow in the telling, we can see how the totally false story that we have today could have arisen without conscious mendacity.

Darwin’s religious views

As for Darwin’s own views, he referred to belief in the punishment of unbelievers as “a damnable doctrine”, and may well have turned away from the idea of a benign deity after the death of his dear daughter Annie. (However, if I understand his Autobiography correctly, he continued to regard “this immense and wonderful Universe” as more than the product of mere chance[1], and eventually retreated into agnosticism only because he regarded the matter as beyond human understanding; I have discussed this here, and how more sophisticated modern creationists misdescribe his views here) .

Young Earth and other varieties of creationism

Crossbedding

The Cococino sandstone layer, showing the cross-bedded structure.  This, when examined together with small-scale and granular texture, identifies it as a wind-swept dune deposit.

Darwin, who was a geologist before he became a naturalist, would be very puzzled by Young Earth creationism, since in his time the Churches accepted (and churchman geologists contributed to) the geological column and the implication of many millions of years. Young Earth creationism and “creation science”, as a claimant to speak for mainstream Christianity, only arose in the mid-20th century. “Creation science” needs to account for the plain facts of geology, and does so in extraordinary ways, asserting for example that the entire Colorado Plateau, successive strata with a depth of over a mile, were laid down and drained within a year by the waters of Noah’s Flood. Hence creationists’ obsession with the Coconino Sandstone, whose texture and cross-bedded structure (as known since before 1945; see here and references therein) are characteristic of a wind-blown desert dune, and their extraordinary attempts to rationalise the claim that it was laid down under water.

Creationism is invariably associated with religion, and with those schools of religious thought that place great emphasis on the sanctity of a particular text. (Since such texts are ancient, they could hardly do other than adopt a creationist viewpoint.) Darwin probably never considered Islamic creationism, Turkey (despite still being a great European power) being seen as remote and exotic. Acceptance of evolution seems to vary widely throughout what one might call the Muslim world, but is a worryingly low 35% in Turkey. Turkey is home to the prolific publicist Adnan Oktar (Harun Yahya), publisher of the Atlas of Creation, which attempts to deny that evolution has occurred by comparing present-day forms with fossils. The Atlas’s scientific methodology, however, leaves much to be desired. Its “caddis fly” image is a photograph, not of an insect, but of a fishing lure. (I fear the problem of Muslim creationism may be deep-seated and widespread. I have written about the emerging alliance between Intelligent Design creationism and conservative Islam in Scotland, while in 1985, the then nominally secularist Turkish Government invited the Institute for Creation Research to help draft the school curriculum.) In the UK, according to a Theos/Comres 2009 survey, only 37% of those surveyed said that humans are the result of purely naturalistic evolution, 28% said we are the result of evolution according to God’s plan, 11% believed in evolution guided by divine intervention, and only 17% embrace separate creation. (The authors of the Theos report on the survey, themselves, describe evolution as “uncontestable”[2].)

There are varieties of creationism. Young Earth creationists accept biblical chronology, and think that present and extinct species coexisted. Old Earth creationists accept versions of the scientifically agreed chronological sequence, but regard each stage as a separate phase of the Creator’s activity. Guided evolution accepts common descent, but treats successive changes as the result of divine intervention (perhaps by intervention at the molecular level). Intelligent Design considers mutation as a random process, and, neglecting the role of selection, improperly infers that it cannot generate meaningful novelty. (In the US, Intelligent Design advocates are generally Old Earth creationists, but in the UK leadership and allies are more often believers in a young earth.)

Creationism in the UK and its opponents; the current Petition

Creationist bodies are very active within the UK. Creation Ministers International has a UK branch (which caused furore by sending a speaker to the publicly funded St Peter’s Academy in Exeter, a mistake by the school that will not be repeated). There is Truth in Science (which sent copies of the creationist pseudo-text book, Explore Evolution, to every school in the UK), and others. Various bodies, such as Skeptics, Humanists, and the British Centre for Science Education, actively work to restrict their influence, and the Scottish Secular Society’s Public Petition PE01530 (with which regular readers will be very familiar) aims to keep creationism from being presented as valid in schools.

The eye, continental drift and biogeography, Mendelian inheritance, the ancestry of whales, and the mythical missing link

GenieEyeDarwin would have been very interested in the direction of creationism in the UK, and the revival of the design argument, which he regarded as refuted by natural selection. When he considered the eye as a structure that at first appeared too complex to have arisen naturally, he pointed out that it could have arisen from a photosensitive spot, through a directional cavity, to an enclosed structure whose fluid would concentrate the light, and eventually, via the development of the enclosing membrane into a lens, to the complexity of the mammalian eye in its present form. We now know that all these imagined stages are actually evident in molluscs.

He would have been delighted by continental drift, which solves long-standing puzzles in biogeography. Biogeography is one of the most convincing arguments in favour of evolution. It explains, as separate creation can not, why the flora and fauna of continental islands are closely related to those of the adjoining land mass, while those of oceanic islands are restricted and exotic. And yet, how come there were marsupials in Australia and in South America, but nowhere else? (North American marsupials crossed from the south, after the relatively recent closure of the isthmus between the two continents). We now know that marsupials appeared when present-day Australia, Antarctica, and South America were joined together in the supercontinent of Gondwanaland, allowing migration of marsupials from their original South American home, and indeed marsupial fossils have been discovered in Antarctica.

He would also have been delighted to learn of Mendelian genetics, which solve the “dilution problem”. Under blending inheritance, a favourable variation would appear in less intense form in the offspring of the favoured individual, but genetic inheritance avoids this. Instead of the character being passed on with half the intensity, it is passed on with the same intensity to half the offspring.

Darwin was ridiculed (still is, by particularly ignorant creationists; see here) for speculating that the behaviour of a bear swimming with his mouth open to catch prey was a clue to the ancestry of whales, which clearly are mammals. Yet within the past 40 years, we have accumulated detailed fossil knowledge (free access review article, from which the image below is taken, here)  of all the intermediate stages linking present-day whales to their even-toed terrestrial ancestors. This is part of a general phenomenon. Darwin famously lamented the gaps

https://i2.wp.com/static-content.springer.com/image/art%3A10.1007%2Fs12052-009-0135-2/MediaObjects/12052_2009_135_Fig27_HTML.gif

Whale evolution ;the first 10 million years

 

in the fossil record, and present-day creationists echo these laments, as if they were still warranted. Thus they commonly repeat a remark made some decades ago, to the effect that all known human ancestral fossils would fit onto a small table. Not any more. The human fossil record is now so rich, that we have more specimens of the relatively obscure species Homo habilis than we have of Tyrannosaurus rex.

 

Skulls

A sample of the skulls of species intermediate between modern humans and other apes

 

So the scientific record (including much not even touched on here), ever since the publication of On the Origin of Species, has been one of steadily reinforcing the central concepts of common descent, and of natural processes driving evolution.

What, then, would Darwin set to today’s’s creationists? Simply this: “Haven’t you been paying attention during the last 156 years?”

Q&A:

GenieFbImageQ: Is there a risk that so uncompromising a talk would put off those sympathetic to creationism?

AS: I would not give this talk to such an audience. There are those whose identity is bound up with creationist religion, whom I cannot hope to reach; those uncertain, to whom I would present the arguments for evolution; and those, like tonight’s audience, who need no convincing.

Q: Are creationists dishonest?

A: Most ordinary creationists are either misinformed or muddled. The higher echelons go through considerable mental contortions, but I have no reason to doubt their sincerity.

Q: How can we respond to those who consider “Goddiddit” a satisfactory explanation?

A: Science is highly valued socially and culturally. So any ideologue tries to recruit science. Hence “creation science,” and devices like imagining the speed of light to have been much higher in the past, so as to allow light from galaxies billions of light years away to have reached us within 6,000 years. “Creation science” is a procrustean bed, on which all observations are distorted until they fit the initial biblical assumptions.

This is contrary to the key moral value of science which is the admission of fallibility. Science as process depends on critical examination and revisability. We need to impart this, not by telling but by showing, and showing by asking. The dandelions on our lawn have short stems, but those over there have long stems. Why might that be?

1] This idea of overall cosmic design is of course the very opposite of the kind of piecemeal meddling that goes by the name of “Intelligent Design theory” today.

(2] Theos is funded by the Templeton Foundation, making it anathema to some exponents of evolution. I have argued that such doctrinal purity is misguided.)

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