Jeffrey Shallit
Department of Computer Science
University of Waterloo
Waterloo, Ontario, Canada, N2L 3G1.
E-mail:
Review by
Jeffrey Shallit
Department of Computer Science
University of Waterloo
Waterloo, Ontario, Canada, N2L 3G1.
E-mail:
David Humphreys is a professor emeritus of chemistry at McMaster University. I recently purchased this videotape at the annual meeting of the Canadian Scientific and Christian Affiliation held at the University of Waterloo.
In a Scottish accent and with good humour, Humphreys mixes flashy chemical experiments (making nylon, exploding a mixture of hydrogen and oxygen, mixing hydrogen peroxide and blood, burning phosphorus in oxygen, etc.) with the argument from design and some explicitly evangelical commentary. He is assisted by a tall blond undergraduate named Doris who appears to be somewhat embarrassed by the whole affair.
Humphreys draws a distinction between the order that can be found in snowflakes and crystals, and natural beauty such as sand ripples, with more complicated order. Snowflakes and crystals, Humphreys says, can be explained by natural causes. But, he claims, "there is a kind of order not well explained by natural causes." In analogy, he points to Mt. Rushmore. Anyone seeing this, he claims, would wonder who made it. Common sense, Humphreys argues, would tell you that such a formation could not be made by natural causes.
After Humphreys made a similar claim in a lecture at the University of Waterloo on July 12, 1996, I pointed out that in New Hampshire one can find the famous rock formation "The Old Man of the Mountain", which closely resembles a carved face of a man. How can one distinguish between such a formation -- which Humphreys concedes was formed by purely natural causes -- and Mt. Rushmore? What test would one use? Humphreys had no good answer then, but he continues to use the analogy in his videotape.
Humphreys argues that the molecules of life give scientific evidence for the existence of a Creator: "the nature of life at the molecular level, at the the cellular level, the level we're going to explore it, it shows the kind of order that gives clear testimony to an intelligent creator."
Humphreys finds photosynthesis amazing: the sun "gives energy at just the right frequency to be absorbed by the chlorophyll in those green leaves." Of course, he has it exactly backwards. Chlorophyll evolved to take advantage of the sun's emission spectrum, not the other way around [5]. He does not mention that there are several kinds of chlorophyll, such as chlorophyll a, b, and c, which have different absorption spectra, nor the fact that other photosensitive molecules, such as carotenoids and xanthophylls, absorb frequencies of light not handled by chlorophyll. Nor does he mention that chlorophyll precursors, such as porphyrins, can be synthesized in Urey-Miller type experiments.
Humphreys is also awestruck by DNA: "All that information, all that special order, is one of the things that points to an intelligent creator..." Once again, Humphreys appeals to the common sense of the viewer: "You know from experience that messages always have an intelligent cause... It's by looking for a meaningful message, it's by looking for information that we can tell whether something's come from blind forces, from natural causes, or whether it's come from an intelligent, creative designer."
But Humphreys seems to contradict himself later in the video, when he asks, "Have you ever wondered how that little firefly managed to flash its message in the forest, in the night sky?" If fireflies send messages with their flashing lights, are they "intelligent"? Is the message the product of their intelligent mind, or is God manipulating the lights in real time? Or is the firefly's message a good counterexample to the claim that every message implies an intelligent creator?
Humphreys also appears to subscribe to genetic determinism: "There are all kinds of differences in size between people and all that's contained in the DNA molecule... the DNA molecule is the molecule that puts together a message that spells out you -- all the characteristics you show were in that message..." This demonstrates a very naive understanding of biology. Size differences clearly have a genetic component, but environment plays a large role. Even genetically identical animals will grow to different sizes if one is deprived of essential nutrients. It is simply not true that "all that's contained in the DNA molecule".
Humphreys finds perfection in nature even when it's not there: "Babies come complete with 110,000 designer genes, all organized and in the right place." Has he never heard of fatal genetic diseases such as Tay-Sachs? A child with Tay-Sachs develops normally at first, but eventually, as fat deposits accumulate in the brain, he dies a horrible death, usually by age five. Indeed, the average person has something like five potentially lethal alleles, but they are not fatal because they are expressed heterozygously. So to claim that every gene is "in the right place" is a gross exaggeration.
Another molecule that amazes Humphreys is hemoglobin: "If only chemical forces were at work to form these molecules you wouldn't even have the variety of forms of hemoglobin that we get in different species." On the contrary, natural selection predicts that there will be different varieties of hemoglobin, and the different varieties will be related by descent -- exactly what we see.
This part of the video differs substantially from Humphreys' 1996 talk at Waterloo, where he made several erroneous claims, such as "hemoglobin in all animals is alike". After that talk, I sent him a detailed refutation of several of his claims by e-mail, but Humphreys never responded.
One property of hemoglobin that Humphreys did not mention is its spectacular affinity for carbon monoxide, with the result that humans are easily poisoned by this colourless, odorless gas. Is that an example of good design? On the other hand, if the structure of hemoglobin is viewed as the product of an evolutionary process with "economic" tradeoffs, and one considers that prior to the invention of the internal combustion engine, humans and their ancestors were only rarely exposed to carbon monoxide, the reason for this poor design becomes more explicable.
Humphreys doesn't have much respect for abiogenesis research: "The chance of a particular order arising in any kind of primordial soup ... is so small that we can say it's negligible ... that's the odds of getting a particular arrangement, 10^(-75)." There is no explanation provided for how this number was computed. Besides, an event having small probability does not mean it cannot occur. If one shuffles and randomly deals a deck of 52 cards, the probability that any particular arrangement will be produced is about 10^(-68). Nevertheless, the fact is that every time one deals a deck, some arrangement is produced. Amazing!
Humphreys points to the excess of left-handed amino acids in living systems as good evidence for design. Natural processes alone, he claims, could not possibly result in such a distribution. He seems unaware of the recent results showing naturally-occurring L-biased amino acids in meteorites [2,3,4,6].
In one of the sillier passages of the video, Humphreys criticizes Urey-Miller style abiogenesis research because an intelligent mind -- the investigator -- arranges the environment. What alternative method of exploring abiogenesis would he suggest?
Humphreys alludes favorably to Michael Behe's recent book, Darwin's Black Box and the notion of "irreducible complexity". But he doesn't even get Behe's definition correct. Humphreys calls a system irreducibly complex if "every part must depend on every other part", whereas Behe's definition is that no part can be removed and have the system continue to function. Humphreys claims that "any system which is irreducible complex is a system which is difficult to imagine developing in a step-by-step process". He omits any mention that, in fact, irreducible complexity is no barrier to evolvability, as pointed out by Jerry Coyne in his review of Behe's book [1].
Humphreys implies that seeking a naturalistic explanation for origins is like hunting for a unicorn: "What I'm interested in is demonstrated reality, not mythical beasts, not inventions of the human imagination." But human imagination has created dozens of gods, from Zeus to Jupiter to Odin to Mithra. Presumably Humphreys would dismiss all these as "inventions of the human imagination", but not the particular god he worships.
Finally, Humpheys concludes his video with a call to read the Bible: "Check out the message of God's word." But even if one buys his weak and flawed arguments for intelligent design, Humphreys offers no reason to believe that the Bible is the word of the Creator. Personally, considering diseases such as Tay-Sachs, I find it more plausible that if the Creator exists, he must be a trickster god, not an all-powerful, loving god.
2. Christopher F. Chyba, "A left-handed solar system?", Nature 389 (18 Sep 1997), 234-235.
3. John R. Cronin and Sandra Pizzarello, "Enantiomeric excesses in meteoritic amino acids", Science 275 (14 Feb 1997), 951-955.
4. M. H. Engel and S. A. Macko, "Isotopic evidence for extraterrestrial non-racemic amino acids in the Murchison meteorite", Nature 389 (18 Sep 1997), 265-268.
5. Anthony W. D. Larkum, "The evolution of chlorophylls", in Hugo Scheer, ed., Chlorophylls, CRC Press, 1991, pp. 367-383.
6. I. Peterson, "Left-handed excess in meteorite molecules", Science News 151 (8) (22 Feb 1997), 118.