Every so often, the Evolution News site run by the Discovery Institute brings in an expert to explain why the adaptations in organisms cannot be explained by natural evolutionary processes. I was about to discuss the argument of one of these experts, when another, even-more-impressive expert showed up. For this post, I’ll discuss the arguments of the first one, the medical oncologist Dr. Stephen Iacoboni. In the next part, I will consider those of the particle physicist Dr. Eric Hedin, who is also Professor and Chair of the Department of Chemistry, Physics and Engineering at Biola University.
I do not doubt that Dr. Iacoboni is an “award-winning cancer researcher”. But somehow these impressive credentials do not carry over into a discussion of natural selection.
Dr. Iacoboni has written two articles at Evolution News, the first A New Look at Natural Selection on April 18, and the second Natural selection subtracts, it doesn’t add – and that matters on May 16. The latter is decorated with the dramatic image of a constipated Polar Bear.
Iacoboni argues that all of the natural world, including all aspects of each organism’s environment, are designed, and it is this design that causes organisms to have adaptations. So has the ability of natural selection to increase the adaptive information in the genomes of living organisms been decisively refuted by his argument? Let’s see … (but no prize for guessing that my answer is going to be “no”).
Dr. Iacoboni’s post (here) brings up examples of adaptations that seem to him to have no possible antecedent. Then he hints at his refutation:
There really is no reasonable way to believe that all of those trillions and trillions of modifications occurred randomly and without a designer.
It has been said many times before but it is certainly worth repeating: Natural selection creates nothing. It only subtracts.
With that, he mentions his alternative explanation for the evolution of adaptations: that all of every environment is designed, as everything in the universe is designed, and that these environments force the organisms’ phenotypes to fit them. He promises more on that in future posts. Leaving the rest of the universe aside, let’s consider the point that evolution “only subtracts”.
Why evolution adds as well as subtracts
Natural selection typically changes the gene frequencies in a population. Can this “create”? It can change the genotype of typical members of a population. If 1% of the copies at a locus are allele A, and the rest allele a, then we expect 0.0001 (that is, 1/100 of 1%) of the individuals in the population to have genotype AA, and 0.0198 of the individuals to have genotype Aa. The rest (98.01%) are aa. Once natural selection has changed the frequency of the A alele to bring it from 1% up to 99%, it is now the AA homozygote that makes up most of the population, with Aa having risen to near 50% and then fallen back to 0.0198. aa will now be the genotype that has a frequency of 0.0001.
A typical creationist response is that these frequency changes don’t matter: “new information” comes into the population only by mutation. That is typical Creationist Information Theory. No actual specialist in information theory would take that seriously. Information theory calculates information using probabilities, not just the fact that both 0s and 1s can occur. A gambler would not take the theory seriously either, if you told them that it doesn’t matter whether you win 99% of the time or 1% of the time, all that matters is that sometimes you win. Though they would suddenly get very interested in making a few private bets with you.
Similarly, when a detective is trying to discover who killed Professor Fudge in the library of the manor house, we will not be very satisfied when the detective simply presents us with a list of everyone who was in the house at the time. We want him to subtract all the ones who didn’t commit the crime.
But when the differences in fitness are differences in viability (survival probability), don’t the deaths of members of the less-fit genotypes simply harm the population, without helping it? If you know anything about population biology, you know that almost all populations have an excess of offspring. Their numbers rise until they run into shortages of resources, such as food or nesting places. And if natural selection kills off members of some genotypes, the population tends to recover, though now with a changed genetic composition. So merely subtracting can be effective in changing the genetics of the population.
Genuinely new genotypes
Looking at more than one locus in the genome, we can see that natural selection really can result in new combinations of alleles. Suppose that we look at two loci, one with alleles A and a, and the other with alleles B and b. If A is rare, with a frequency of 0.001, and if B is also rare, with a frequency of 0.0001, then there may be no genotypes in the population that contain both A and B.
If both are favored by natural selection, as each rises in gene frequency at its locus, sooner or later mating and recombination will bring them into the same individual, and into the same haploid gamete. Initially, we had no AB gametes; now we have them.
With more than two loci, the effect is even greater. When the favored alleles at many loci are all rare, it is unlikely that they can all be found in one individual. That changes dramatically as they all rise in gene frequency.
Frequencies matter, and natural selection can change them. That can result in bringing together new combinations of alleles in the genome. You’d never know that from Iacoboni’s dismissal of natural selection.
The ghost of Edward Blyth
Actually, interestingly enough, Iacoboni does think that natural selection is a real phenomenon.
Reducing this argument to more tangible physical terms, it seems that Darwin was unwilling to acknowledge that the fix for conscious selection was already embedded in an environment which had the innate ability to nurture creatures with capabilities suited to it. It is actually very important to be able to extract oxygen out of water if you are going to be a fish or a mollusk or a crustacean. It is actually important to have flippers and not fingers if you are going to be a marine mammal or penguin. It is important to have thick fur and to store fat if you are going to live in the snow. If you want to fly above it all you better have hollow bones and extremely strong pectoral muscles. If you want to burrow below the fray, you better have proper claws for digging. And if you are a pine tree, you need to have antifreeze in your needles if you are rooted beyond certain latitudes or elevations.
Yes, indeed, natural selection is true. But that selection is not accomplished in the oxymoronic fashion of the inanimate acting with purpose. It is instead that the environment itself was designed with purpose so that it had the transcendent ability to nurture the arrival and survival of purpose-driven organisms on our glorious blue planet.
A somewhat similar argument was made by Edward Blyth, in articles in 1835-1837. Blyth was an English ornithologist who worked mostly in India. Charles Darwin corresponded with him and valued his expertise on the birds of India. Blyth did not argue that natural selection brought about evolutionary change, but rather that it forced organisms to conform to their archetypes, keeping them precisely adapted and not allowing them to change away from that. (It has been suggested that Darwin got natural selection from Blyth’s articles, but the dates of the discussion of it in Darwin’s notebooks disprove this).
Iacoboni goes farther than Blyth – he sees the environment as causing the “survival” of “purpose-driven organisms” but their “arrival” as well. So the environment drives the process, and the biological process is “survival” of better-adapted organisms. But he doesn’t call that “natural selection”. Thus he has refuted natural selection while invoking it. All natural selection can do is “subtract”, but if the organism is not well-adapted to its niche, it gets subtracted.
Iacoboni is a teleologist, who sees the whole universe as designed. To him it is that “telos” that brings about the change, and natural selection is just a fancy and misleading name for the grubby processes doing the dirty work.