Petitions and politics in science

In a recent discussion on a listserv for physics teachers, someone strongly recommended the book The Politically Incorrect Guide to Science by Tom Bethell, saying that it exposed how mainstream science was suppressing some ideas for non-science reasons, in particular how the great weaknesses of evolutionary theory were being hidden.

I had not read this book myself but these kinds of arguments are familiar to me and Bethell had written an article describing his own book. It struck me as extraordinarily shallow, rehashing arguments that have long been discredited, and invoking misleading (and old) chestnuts about evolution occurring only by chance, and missing transitional forms, etc. In fact, he seemed to have drawn his arguments against evolution from the playbook of the intelligent design creationists, in particular Jonathan Wells’ book Icons of Evolution.

He even made the argument that the only thing that has been seen is ‘microevolution’ (small changes within species) and not macroevolution (change from one species to another). But the distinction drawn between micro- and macroevolution is untenable, since it has long been realized that there is a large overlap between varieties within species and between species as a whole, making the drawing of such distinctions difficult. Darwin himself pointed this out in his On the Origin of Species (chapter II), where he emphasized how difficult it was for even experts to classify whether animals were varieties within a single species or different species.

It is amazing that in this day and age people like Bethell still bring up Haeckel’s embryos. Modern biologists don’t take Haeckel’s misleading sketches seriously anymore since his theory was discredited more than a hundred years ago and only intelligent design creationists (IDC) keep bringing it up repeatedly to argue that scientists falsify things in order to buttress the case for evolution. In the documentary A Flock of Dodos IDC advocate John Calvert talks about how biology textbooks use Haeckel’s figures to mislead children but when asked to show this, thumbs through some textbooks and cannot find any examples. He had simply accepted this folklore uncritically. What use Haeckel has now is purely pedagogical.

The Haeckel case is analogous to someone finding that the Bohr model of the atom is still being taught in middle school science textbooks, “discovering” that Bohr’s model violates Maxwell’s laws of electromagnetism, and thus concluding that quantum mechanics is wrong and that children are being misled into accepting it. Quantum mechanics has come a long way since the Bohr atom and does not depend on it, just like evolutionary biology and Haeckel’s embryos. To keep bringing it up is a sign of desperation

Bethell’s argument about the fact that no one has seen half-bats and that therefore step-by-step evolution could not have occurred, reminds me of those people who say that it is absurd that an electron can go through two slits or that twins age differently based on their speeds. After all, has anyone actually SEEN an electron go through two slits? Has anyone actually SEEN twins age differently? If we haven’t seen such things directly, they must not occur, right? I have described earlier how incomplete the fossil record is, because fossilization is extremely unlikely, and how arguments that depend on the existence of gaps in the fossil record can never be satisfied because new gaps can always be created.

As I have said in this series on evolution, to really appreciate the theory one has to get beyond the simple minded rhetoric of the kind that Bethell indulges in and look at the underlying details and the mathematics. The question of whether evolution is a “fact” is a red herring. “Theory” and “fact” are fluid terms in science. What is true is that the fully developed theory of evolution, known as the neo-Darwinian synthesis, is the most productive and useful theory in biology today, and forms the basis of almost all research in that field.

People who dislike the theory of evolution often point to the petition that the Discovery Institute (DI), the main driver of Intelligent Design Creationism (IDC), put out signed by 700 people that says: “We are skeptical of claims for the ability of random mutation and natural selection to account for the complexity of life. Careful examination of the evidence for Darwinian theory should be encouraged.” Such people cite this as evidence that the theory is weak and then ask: “Why are so many scientists jumping off the evolution band wagon?”

But scientists are taught to be skeptical and to examine carefully the evidence for any theory. And if a theory (like evolution) challenges their religious beliefs, they are likely to be even more skeptical of it. That is a natural human tendency. It does not take any effort for a mathematician or physicist or philosopher to say she is skeptical of evolution, just as it does not cost any biologist anything to say that he is skeptical of the big-bang. After all, in each case, they are not personally working with that theory and are unlikely to know anything about it in any detail and thus can let other factors have a greater influence. As of the time when there were 400 people who had signed on, about 80% were not even biologists. (The story of one religious scientist who signed on to the Discovery Institute statement and only later realized what was going on can be read here.)

Another problem with the petition wording is that although Darwin proposed the mutation and natural selection mechanism, developments since then have added other mechanisms such as gene flow and genetic drift, so even a biologist who sees no problem with evolution would agree that mutation and natural selection alone are not sufficient.

I personally am skeptical of ANY theory in ANY field as being the last word (or the ‘truth’) on the subject because the history of science teaches us that scientific theories have always been provisional. So for me the DI statement itself is nothing more than a platitude. The fundamental issue is whether the biological community feels that evolution is in a crisis, and as far as I am aware, the biological science community does not think so and continues to use that theory as the foundation for their work. So these kinds of statements are just meaningless. When biologists start using alternative theories to generate predictions and start getting positive results, then we can take those other theories seriously.

It is important to realize that despite so many years of pushing intelligent design creationism, the people at the Discovery Institute have not been able to generate even one prediction, let alone do any experiments to investigate their theory. What they are doing is not science, it is lobbying and public relations.

Statements like the ones put out by the Discovery Institute on evolution are, however, useful as indicators of what people desire or yearn for.

For example, I am skeptical of the idea of dark matter as the explanation for the anomalous velocity distribution of stars on the arms of spiral galaxies. Why? Mostly for aesthetic reasons. It seems a bit contrived to me and the idea of huge amounts of matter surrounding us that we cannot detect reminds me uncomfortably of the arguments for the ether before Einstein’s theory showed that the ether was a redundant concept.

I am hoping that a nicer theory than dark matter comes along and I know I am not alone in feeling this way and that other card-carrying physicists share my view. So if someone handed me a petition saying that I was skeptical of the theory of dark matter and would like the evidence for it to be examined carefully, that statement’s content would not be objectionable to me. I would totally agree.

But I would not sign because it is pointless. I have not done any real work to support my misgivings. I have not developed an alternative theory, generated hypotheses, made predictions, or explained any existing data. Physicists who actually work on the spiral galaxy problem (even if they were completely outnumbered by the people who sign a petition dismissing dark matter theory) would be perfectly justified in ignoring me and any other physicists who sign such a petition in the absence of any substantive counter-theory.

What the DI petition on evolution tells us is that there are about 700 people who wish and hope that a theory more congenial to them than evolution comes along. That’s fair enough but hardly major news. They have every right to feel that way and to say so. But it is by no means a measure of the merits of the theory, however many people sign on to it, and it is dishonest of the Discovery Institute to make such a claim.

Bethell’s thesis that the scientific community is conspiring to suppress the truth about the weaknesses of evolution is silly. Given that the US has high levels of religiosity and public skepticism about evolution and widespread unease that evolution is undermining religious beliefs, any scientist who found good evidence for special creation would be deluged with funding from both government and private sources and receive high visibility and acclaim. Furthermore, such a discovery would open up vast new areas of research. In such a climate, why would any scientist not publish findings that provided evidence for special creation?

People like Bethell are trying to achieve by public relations what they cannot do using science. They are not the first to try to do this and will not be the last. But they will fail, just like their predecessors.

POST SCRIPT: The insanity of the employer-based health care system

This question posed at a Democratic presidential candidates forum illustrates perfectly why we need a single-payer, universal health care system.

The story of evolution-20: How selection advantage arises in evolution

In the mathematics of evolutionary change, the selection advantage is a key mathematical quantity that determines the rate at which a favorable mutation spreads through the population. The selection advantage is a quantification of the net result of advantages that a variety of a species gains by virtue of its fertility and fecundity and longevity. As we saw before, even a small selection advantage can lead to rapid spread of the mutation.
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The story of evolution-19: The-Boeing-747-in-the-Junkyard

As I have emphasized repeatedly in this series, the hardest thing to appreciate about evolution is how a cumulative sequence of very tiny changes can lead to big changes. The problem is that our senses can only detect gross differences between organisms and our minds can only comprehend short time scales and to appreciate evolution requires us to overcome those limitations. This is why skeptics need to actually study the details and convince themselves that it works.
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The story of evolution-18: Missing links

About ten years ago, a group of engineering students came into my office. They were taking part in a scavenger hunt during Engineers Week and the one item that was very hard for them to find was a ‘slide rule’. They had little idea of what it was and no idea how it worked or what one even looked like but they knew it was old technology and they figured that I was old enough to possibly own one.

They were partly right. I had once owned a slide rule as a physics undergraduate in Sri Lanka but unfortunately did not have mine anymore.

For those not familiar with slide rules, the standard type looks like a ruler with another sliding ruler attached, and you use it to do complicated calculations. It was the precursor to the handheld calculator but with the arrival of cheap electronic versions of the latter, the slide rule went extinct. I actually owned a more unusual type of slide rule that was cylindrical rather than linear and was like a collapsible telescope. It had the advantage that it was small enough to carry around in your pocket, and being able to whip out a slide rule when the occasion demanded defined the nerds of that time.
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The story of evolution-17: How species diverge

When my daughter was quite young, about five or so, the question of where people came from came up in a mealtime conversation. Naturally we told her that human beings had evolved from ancestors who were monkey-like and then became human-like. She sat there for a while silently digesting this interesting bit of new information and mulling it over in her mind. It seemed clear that she was not at all disgusted or even bothered by the thought that we were related to the monkey family. That kind of revulsion seems to be something that has to be acquired, often nurtured by religions.

But something was bothering her and she finally articulated it, asking “But when that happened, wouldn’t the mother monkey notice that her child looked different?”

She had hit upon an issue that many skeptics of evolution raise. They argue that there is a contradiction if we assume that we had evolved from an ancestor species that was so different from us that we could not interbreed with that species. Surely, the argument goes, doesn’t evolution imply that if species A slowly evolves into species B, then there must be a time when the parent is of species A while the child is of species B? Isn’t it a ridiculous notion for parent and child to belong to different species?
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The story of evolution-16: The evolution of the eye

The eye is one organ almost invariably brought out by creationists to argue against evolution. How could something so complex have possibly evolved incrementally, they ask?

Darwin himself suggested the way that the eye could come into being. Due to the fact that eyes don’t fossilize and thus leave a permanent record, it is hard to trace back in time and see the various stages in the evolution of the eye as linear developments. So he looked instead at the eyes of currently existing different organisms at intermediate stages of development, and concluded (On the Origin of Species, 1859, p. 188):

With these facts, here, far too briefly and imperfectly given, which show that there is much graduated diversity in the eyes of living crustaceans, and bearing in mind how small the number of living animals is in proportion to those which have become extinct, I can see no very great difficulty (not more than that in the case of many other creatures) in believing that natural selection has converted the simple apparatus of an optic nerve merely coated with pigment and invested with transparent membrane, into an optical instrument as perfect as is possessed by any member of the great Articulate class.

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The story of evolution-15: How species evolve

The final feature that needs to be addressed is the probability of mutations cumulating to produce new organs and species.

This question lies at the heart of many people’s objections to evolutionary ideas. They cannot envisage how infinitesimal changes, each invisible to the eye, can add up to major changes. That is because they tend to think that the two foundations for this to occur (the occurrence of successful mutations and the mutations then spreading throughout the population) are both highly unlikely, and so that the chance of a whole sequence of such processes occurring must be infinitesimally small.
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The story of evolution-14: How a single mutation spreads everywhere

In the previous post, we saw that if we start with a trait that is present in just 0.1% of the population (i.e., f=0.001), and if this has a small selection advantage of size s=0.01, this will grow to 99.9% (F=0.999) in just under 1,400 generations, which is a very short time on the geological scale.

But in a population of one million, an initial fraction of f=0.001 means that we are starting with about 1000 organisms having the favorable mutation. But it could be argued that new mutations usually start with just a single new kind of organism being produced in one single organism. How does that affect the calculation?

Suppose that you have a population of organisms of size N and they all start out having the same gene at a particular position (called the ‘locus’) on one of the chromosomes that make up the DNA. Now suppose a random mutation occurs in just one organism, the way that it was described in an earlier post in this series describing the shift from violet to UV sensitive sight in some birds. Most of the time, even a favorable mutation will disappear because of random chance because (say) that mutated organism died before it produced any offspring or it did produce a few and that particular gene was not inherited. But on occasion that mutation will spread. How likely is it that such a single mutation will spread to every single organism (i.e., become ‘fixed’ in the population)?
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The story of evolution-13: Differential rates of survival

Of the three stages of natural selection outlined before, the only one that occurs purely by chance is the first one, that of the occurrence of mutations. I discussed how although the chances of producing a favorable mutation by changes in any individual site in the DNA (called ‘point mutations’) on an individual member of the species is very small, when the number of individuals in a species and the long times available for the changes to occur are factored into the calculation, the result is that such mutations are not only likely, they are almost inevitable to occur and furthermore are likely to occur many times.
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The story of evolution-12: Population genetics and the Hardy-Weinberg law

In the previous post, I discussed the puzzle posed by a naïve understanding of Mendelian genetics, which was that one might expect that organisms that displayed recessive gene traits would slowly disappear in a population while those with dominant gene traits would grow in number. But if that were true that would prevent new mutations from gaining a foothold in the population and growing in number, if it happened to be a recessive trait.

The crucial work that formed the breakthrough that revived the theory of natural selection was done in 1908 by G. H. Hardy (a Cambridge University mathematician and author of a fascinating book A Mathematician’s Apology) and Wilhelm Weinberg (a German physician), working independently. What is nice is that the result is quite simple to derive, and surprising.
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