Evolution from Space: a theory of cosmic creationism by Sir Fred Hoyle and Chandra Wickramasinghe, Touchstone Books, Simon & Schuster, NYC, 1981. ISBN 0-671-49263-2
[This review was written September 4th, 1990. Since then, some scientists have claimed to find fossil bacteria on meteorites from Mars. While other scientists dispute this, it's at least possible pro-panspermatic evidence. We have not found bacteria in cometary dust, but then we haven't looked carefully. As of 2011, people are still actively wondering about life on Mars or in the oceans of Europa, Callisto, Titan, or Enceladus.]
This strange book builds on three other books by the same authors, Lifecloud, Diseases from Space, and Space Travellers: The Bringers of Life. You may remember Fred Hoyle as the man who championed the Steady State theory of the universe. He is an established member of the scientific community, justly famous for working out the astrophysics of stellar fusion and predicting the cosmic abundances of the elements.
He seems to use this solid reputation as a base from which to challenge conventional science. The Steady State theory was sort of like that, though it was quite a serious contender in its day (and even now Hoyle maintains that quasars are not as distant as people think, so the evidence for Big Bang is not a strong as it seems). He also has maintained that ice ages advance and retreat much faster than people suppose.
Another maverick theory he supports, together with Wickramasinghe, is panspermia. For those who may not have heard of it, panspermia is the idea that life started on Earth from spores of bacteria or other microbes falling in from space. They agree with this and thinks it is still happening.
They believe there is a steady rain of bacteria, viruses, plasmids, and other microbial forms, possibly even including insect eggs, falling on Earth. This rain of alien organisms is supposed to introduce new genes into Terrestrial evolution, and to account for sudden changes in the evolutionary record. The spores come from cometary debris, and comets are supposed to be inhabited by these microbes.
How do the comets come to be infested? H & W believe that space at large has been seeded by some intelligence or other. And who is it and where did it come from? They don't know, and admit it, though in Chapter 9 they propose that the only rational view is that the seeding intelligence was produced by a previous intelligence, and so on back forever, converging to God as a mathematical limit, identifying God with the universe. A sort of Steady State Theology.
Well, on the whole, I remain unconvinced. What they do show is that panspermia is possible. Panspermia started as a theory put forward by Svante August Arrhenius, in 1907. When the sterilizing effects of radiation and vaccuum were discovered, people tended to dismiss panspermia on the grounds that microbes could not survive the trip.
H & W cite latter data showing that several known species of bacteria can survive indefinite exposure to radiation and vaccuum, and that such bacteria can land gently enough on Earth to survive. They claim the radiation and vaccuum resistance is evidence that bacteria are adapted to space.
This is all well and good, provided the bacteria are already out there. At least their theory is testable. They say the surface of Mars should have lots of dormant bacteria. Dust samples from passing comets could also confirm or refute the theory, as could general sampling of micrometeors. (Though this last is not very easy, since the micrometeor and the space probe tend to have very different velocities. Any bacterial passengers would be smashed unless caught gently.)
They also cite some high-altitude balloon experiments that caught surprising numbers of normally terrestrial bacteria in the upper atmosphere. But I don't think we know enough about weather and turbulence to say these bugs weren't kicked up from below, rather than drifting down from above.
But why should we bother with panspermia? What's wrong with supposing life arose on Earth? Well, Hoyle and Wickramasinghe are creationists, just as it says in their subtitle. They are almost certainly not Biblical literalists; in fact, they appear to be philosophical pantheists. But they have this in common with conventional creationists: they believe Darwinian evolutionary theory to be an inadequate explanation.
In fact, perhaps because criticism is easier than solution, I found their critique of Darwinism more interesting than their case for panspermia. See the next section.
Like conventional creationists, H & W believe conventional Darwinism is an inadequate theory for the production of Earth's biota. They have much more in common, too. I have read a lot of creationist literature, one way and another, and I can see the overlap plainly. Like conventional creationists, H & W complain of the reception they get (roundly ignored, rather than ridiculed or persecuted). They castigate the scientific community for intellectual laziness and stuffiness, and they explore the psychological reasons for resorting to Darwinism despite its manifest inadequacy.
H & W also use many of the same arguments that conventional creationists do, though with their own new wrinkles. For one, when creationists discuss the origin of life, they often calculate the odds on producing some short gene or simple protein by sheer chance. They make generous concessions for the speed and abundance of the random generation process, even for the required fidelity. Still, the answer always comes out to one chance in ten to the something horrid. H & W make similar calculations with similar results.
These calculations should certainly give a conventional Darwinian pause, but I never felt they were exactly the right calculation. They tell you how unlikely any one origin of life is, but how many origins are there? If there are enough possible origins, then the conventional view is quite adequate. H & W at least address this problem, though they don't think much of it:
The tactic is to argue that although the chance of arriving at the biochemical system of life as we know it is admitted to be utterly minescule, there is in Nature such an enormous number of other chemical systems which could also support life that any old planet like the Earth would inevitably arrive sooner or later at one or another of them.
This argument is the veriest nonsense, and if it is to be imbibed at all it must be swallowed with a jorum of strong ale. The two commonest molecules in the universe are hydrogen, H2, and carbon monoxide, CO. Joining these two gives formaldehyde, H2CO, and joining six formaldehyde molecules into a suitable structure gives glucose. Thus the basic way in which terrestrial biology obtains energy, through the fermentation of glucose, is not a mere face in the crowd.... The use of glucose is a highway. Nor is there a profusion of chemical systems in which glucose can be used, otherwise chemists would long ago have found at least some of them. And if obtaining energy from glucose were such an easy matter it would long since have been found possible to circumvent the very complex sequence of reactions whereby the energy is actually yielded in terrestrial biology. So far from there being very many indistinguishable chemical possibilities, it seems that we have an exceedingly distinguishable system, at best. [p 28]
I wish I could be sure that chemists had been looking at all hard for alternative ways to ferment glucose. Nor am I pleased with rhetorical devices like "veriest nonsense" and the "jorum of ale." But the idea of the argument looks sound: look for a fundamental biological process that has a good chance of being unique or optimal and estimate its a priori probability. I would like to see it more carefully executed, if that is in fact possible.
Another line of reasoning common to H & W and conventional creationists is based on the lack of intermediate forms. New species, higher taxa, and new features often appear abruptly in the fossil record. The creationist contention is, of course, that these gaps are evidence of God's (or the Panspermia Agency's) intervention.
Conventional Darwinians are particularly sensitive on this front at the moment, because there is division in their own ranks over the issue. On the one hand is the standard "gradualist" view, according to which the intermediate forms existed but simply weren't fossilized or haven't been discovered yet. On the other hand is the "punctuated equilibrium" school, which holds that the fossil record is complete enough now to demonstrate that there must have been these sudden changes. Of course, they mean a few millenia when they say "sudden," not a single generation. There are also many subsidiary arguments about the alleged incompleteness of the fossil record, and how sudden is "sudden," and, interestingly, accusations that the punctuationists are playing into the hands of the creationists.
H & W add a new feature by getting quantitative about it:
Man diverged from the gorilla about seven million years ago, and in that time only a single neutral mutation has appeared to make a difference between the alpha-globin chains of gorilla and man. If we take the average generation time of our human ancestors to have been twenty-five years, and the average generation time of gorilla ancestors to have been ten years, the sum of the number of human generations and gorilla generations that have occurred since the divergence seven million years ago is about one million.
If the alpha-globin chain had only a single permitted neutral amino acid variation, ... the chance of a DNA copying error causing a change of any particular amino acid would be about one in a million generations. In the case of the alpha chain there are probably some twenty to thirty neutral changes possible, however, and any one of them might have happened in the total of one million generations since man and gorilla diverged on the ancestral tree. The chance of a copying error is therefore some twenty to thirty times smaller than we have just calculated, about one in twenty to thirty million per generation.
This is a very slow rate. Yet it is only this very slow mutation rate that Darwinism has to work with. It is not only inadequate to explain the evolutionary changes that have occurred, sometimes over quite short intervals for both plants and animals, it is woefully inadequate. [p18]
A quick trip to the Encyclopedia of Science and Technology confirms the accuracy of this estimated mutation rate. The human haploid genome has about ten billion nucleotides in it. At the mutation rate given by H & W, there should be about 300 mutations per generation. Over a million generations, that's 300 million mutations. The various species of great ape differ from humans by about 1% of their DNA, chimps being closest; that amounts to about 100 million differences. Gorillas might easily have three times that. In any case, they are in the same range.
H & W then demonstrate the "woeful inadequacy" of such a mutation rate by calculating the average number of generations it would take to mutate one protein into another, assuming only ten crucial amino acids in its sequence. It's about 10 to the 19th generations; Earth is only about 10 to the 8th seconds old. Yet presumably a great many highly apt proteins have been introduced from somewhere. A conventional Darwinian would presumably invoke some other form of mutation (though I don't know what that form would be) or claim a huge variety of viable possibilities. A conventional creationist would invoke God. H & W invoke the Panspermia Agency. Acts of faith, all three, so far as I can see.
I will point out that, if the mutation rate is indeed this slow, it is inadequate for both gradualist and punctuationist evolutionary theories. Both depend on the natural selection of variations to drive evolutionary engine; they merely disagree over the range of speeds at which this engine runs. Hoyle & Wickramasinghe claim the engine is much too weak to drive life as far as it is observed to have gone.
A comment about mutations:
They seem to forget that there are many mutations that do occur that are basically meaningless. For example, there is a small probability that blue eyes will crop up in any brown-eyed population. Other relatively harmless mutations happen all the time. Other not-so-harmless, but common mutations happen. Juvenile Diabetes crops up suddenly in a family, other things like cross-eyedness, propensity to heart disease, and so on.
It's difficult to perceive an unexpected redhead as a "mutation," but they do happen.
I'm sorry if I gave the impression that Hoyle and Wickramasinghe don't know about neutral mutations. They certainly do. When H & W made their calculation of the base mutation rate and the resulting time needed to produce a given enzyme, they explicitly discussed the fact that the difference between mammalian globulins are all probably neutral mutations. That was just one example; they mention neutral mutations several places in their discussion.
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