Eric Hedin isn't sure what natural selection does

[Ratchet Gif]
By Arglin Kampling. From Wikimedia, CCA 4.0.
Is this the first GIF we have used?


The ID advocacy site Evolution News has had a series of posts by the physicist Eric Hedin. The theme has been that adaptive information in biological organisms info cannot have been produced by natural processes, because these always degrade information. Hedin is a well-trained physicist. He is currently the Professor of Physics and Astronomy and the Chair of the Department of Chemistry, Physics, and Engineering at Biola University, and he trained in plasma physics at my own university.

With that strong background in physics, we should be able to rely on his statements about the increase of the amount of biological information which is possible owing to ordinary physical and biological processes. Here’s what his says at one point in this recent post at Evolution News):

Could a natural information ratchet exist? Since our goal is to understand whether life is an information ratchet, we first need to examine what kind of mechanism might be required to cause a living system to ratchet up its information content over time. To increase information means to select outcomes that correspond to a greater level of functional or meaningful complexity. The only way for this to happen is if the selection mechanism (in other words, the ratchet) is designed to produce the target outcome, and this means that the mechanism must already contain the information specifying the target. A physical mechanism cannot produce any information beyond what it already contains.

I have complained in a previous post about his statements about conservation of information and about there being no natural process that can account for the information accumulated in living things. Here it is again.

Can it be that Professor Hedin has got his basic science wrong? Say it ain’t so!

Well, it ain’t so in one case. If we have a population that consists of only one individual, and that individual reproduces exclusively clonally, by budding off a single offspring identical to itself, then Hedin is right. There is never any other individual in the population than that offspring, and no opportunity for natural selection to act. If a mutation occurs, the altered genotype is immediately 100% of the population.

Mutation accumulation lines

Geneticists actually use such situations as an experimental design, when they want to see as many as possible of the mutations that occur, both advantageous and deleterious. These one-individual populations are called “mutation accumulation lines”. Of course many species cannot reproduce with only one parent, and cannot reproduce by budding. The closest we can come to a clone in, say, mice, is to have a population of two individuals, who are brother and sister, and mate those every generation. But that allows natural selection to occur for one or two generations for the average mutation. So the spectrum of mutations accumulated in the population is partly biased against deleterious mutants. Which suggests that in all cases other than a clonally-reproducing population of one single individual, there will be some natural selection occurring.

Why Professor Hedin gets it wrong

So when there is, not a single individual, but a population of individuals, then Eric Hedin’s analysis has to ask what the effect of natural selection is, not just what the effect of accumulated mutation is. He sounds as if he is only taking mutation into account.

In his next paragraph, he deals with natural selection:

Darwin’s Proposed “Ratchet”

What about Darwin’s proposed “ratchet” mechanism of natural selection based on survival of the fittest? The mechanism invoked here already contains a high degree of functional complexity (all the complexity residing in a living organism). But what can this “ratchet” do? No more than it was designed to do — namely to reproduce daughter organisms according to its inherent mechanism of reproduction. Variations in the organism’s genome, by any unguided process, may lead to an increase in fitness and therefore survivability. But natural processes cannot produce unnatural results. Selection based on the ratchet mechanism of increased fitness cannot of itself produce novel complex functionality if each successive small change does not give some increased advantage towards survival and reproduction.

(We should note that Darwin never used the word “ratchet”. Daniel Dennett did, in his writings on natural selection.)

Dr. Hedin returns to the role of natural selection in the paragraph following that in his post:

The allure of Darwinism is that it suggests a process by which a population of organisms can ratchet up information and increase organismal functionality. A common misunderstanding of evolution is to assume that it can do more than steadily lock in natural variations that increase survivability. The error is in ascribing to this process the ability to ratchet up the information content of a simple common ancestor until all the complex, functionally coherent species of life on Earth have formed. But as shown in our examination of the functionality of any ratchet mechanism, it cannot produce an outcome beyond what it was designed to achieve. With information as the outcome, the mechanism can only reproduce the level of information it already contains.

Does Hedin think natural selection can increase information?

Now, this is puzzling. In the preceding paragraph it was clearly stated that natural processes could not add meaningful biological information to the organism, unless the process already contains the information. That seems to say that natural processes, including natural selection, cannot possibly increase the specified (adaptive) information. The natural processes can at best transfer information that they already have.

But he does acknowledge that natural selection in a population can “steadily lock in natural variations that increase survivability”. That would involve increasing the specified information in the population. This would seem to completely contradict his own earlier statements. He says that “selection based on the ratchet mechanism of increased fitness cannot of itself produce novel complex functionality if each successive small change does not give some increased advantage towards survival and reproduction”. The later statements say, in effect, that actually natural selection can increase the content of adaptive (specified) information. The implication is that selection can produce increased information content in the genome if each small change on the way does give some increase in fitness. The previous impossibility has turned into a possibility. It is just that natural selection and mutation (and other ordinary evolutionary processes) cannot produce “unnatural” results, really big increases in “complexity”. Hedin continues:

Another Process at Work

Given the obvious, that the complexity of organisms on Earth has increased through time from single-cell archaea to functional multicellular creatures, some process other than a supposed evolutionary information ratchet must have been at work. The genomic information content of the prokaryotic cells descriptive of the earliest life on Earth falls far short of the greater information content and complexity of advanced life. An intelligent mind is the only known source for the necessary input of complex specified information throughout biological history.

Hedin’s actual conclusions

So Professor Hedin has argued, in effect, that:

  1. Natural evolutionary processes cannot increase the adaptive information of a population of organisms, because there is a conservation law preventing that.
  2. … except that they can increase the adaptive information in the population, they just cannot increase it to an “unnatural” extent.
  3. And it is his (unsupported) opionion that the increases of “complexity” in living things involve those kinds of “unnatural” increases.
  4. … and therefore those require Design Intervention.

A promised conservation law that prevents information from being increased by natural selection is described. Then it evaporates and is replaced by Professor Hedin’s personal incredulity.

I would add that the information in the genome does not come from nowhere – the process of natural selection is part of the flow of energy through the biosphere, and is accompanied by an increase of entropy in the whole system, with adaptation capturing energy and slowing the increase of entropy.

Your opinion?

Have I got this wrong? I hope that someone, perhaps Dr. Hedin himself, will let us know.