thinkevolution.net

“Are there any technological advances that have been made because of a belief in evolution?”

So asks an essay published by Answers in Genesis, an organization promoting their soon-to-open Creation Museum. The museum directly challenges modern scientific understanding, so Answers in Genesis is justifiably concerned that the enterprise may be seen as “anti-science.” Their response to this concern includes the same empty rhetoric that evolution-deniers have been trotting out for ages: evolution isn’t relevant, because none of the scientific technologies of our time have anything to do with evolution.

Nonsense, of course. In medicine alone, the case for the importance of evolution has been made again, again, again and again. But why not have another go at it? This week in PNAS, researchers describe how they tracked the evolution of a deadly Staphylococcus bacterial strain in a single patient using genomics technology. The problem of antibiotic resistance and how it evolves is old news, but unfortunately it remains both grave and immediate. But that’s what’s so exciting about this article, which demonstrates a method of identifying adaptations in bacterial strains evolving in real time in real patients. By characterizing the pathogen as it mutated, these scientists were able to determine which new changes increased its lethality. Now, other Staphylococcus strains can be screened in other patients to predict how they will respond to antibiotic therapies, potentially increasing patient survivorship and constraining evolution of antibiotic resistance.

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Evolutionary biologist Michael Lynch has published a paper in PNAS this month in which he takes to task scientists in general, and evolutionary biologists in particular, for interpreting “virtually every aspect of biodiversity in adaptive terms.” His language is aggressive: he throws around words like “untenable” and likens the tendency of biologists to dramatize the power of natural selection to the invocation of an intelligent designer. At the end, he writes, “This tone of dissent is not meant to be disrespectful.” Given that he has specifically criticized some of his colleagues, it’s inevitable that some will be offended. But I love this paper, I’m thrilled it’s out there, and I hope it’s making a big splash.

For those interested in my wee little opinion, here’s why:

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Today’s cover story in Salon is an interview with biologist Lewis Wolpert, who argues that the propensity for religious belief is wired into our biology and is an evolutionary product of natural selection.

Wolpert is an atheist. He theorizes that the ability of early humans to understand causality—pounding this nut with this rock will break it open—enabled tool-making, which was an evolutionarily successful strategy. And thus the establishment of this causal worldview necessitated an explanation for everything:

Salon: So once you have an understanding of cause and effect, then ignorance is no longer tolerable? You want to explain everything.

Wolpert: Exactly. You know, we cannot tolerate not knowing the causes of things that affect our lives.

There’s a fairly logical flow of reason to this theory, and I’m all for thought experiments. But is this science? Perhaps Wolpert doesn’t claim any particular authority for this argument. But wait, right there in the title of his new book, Wolpert hauls in the “evolutionary explanation” juggernaut: Six Impossible Things Before Breakfast: the Evolutionary Origins of Belief. The problem here is that Wolpert’s ideas may be reasoned, but they are not evidenced. Science is an evidence-based discipline. The fact that Wolpert is an eminent (developmental) biologist may only exacerbate the problem, since so much authority is accorded to scientists. You know, because their discipline is so evidentiary.

Well, despite his training and esteemed contributions to science, perhaps Wolpert has relaxed his criteria for discerning facts. But what’s this about lack of evidence for qi, the energy manipulated by acupuncturists?

Salon: Maybe the scientific instruments that we have at our disposal just can’t detect anything about qi.

Wolpert: Sorry. When they invented qi, how in the hell did they know what an energy field was? They hardly had a concept of energy. I mean, if you go back and look at their evidence, I’m afraid it was a nice set of ideas, but I’m terribly sorry, evidence matters. And that’s what causal beliefs are really about. If we believe that something has a particular cause, we should be looking for the evidence.

So evidence does matter. But so, apparently, does hubris:

Wolpert: My argument is that causal understanding gave rise to toolmaking; that was the evolutionary advantage. It’s toolmaking that’s really driven human evolution. This is not widely accepted, I’m afraid, but there’s no question about it. It’s tools that really made us human. They may even have given rise to language.

No question about it? There must be a great deal of evidence for there to be no question about it… But if there were a great deal of evidence, it would be rather well-accepted, wouldn’t it? Let me be clear: intellectual discourse makes me happy. Let’s talk about the evolution of the psyche. But let’s not imply that it’s science. Evolution is such a fun explanation to invoke, but flinging around adaptive arguments willy-nilly just gets everyone into a lather and makes actual science that much more difficult to integrate into the popular consciousness.

Indeed, it looks like the anti-evolutionists at Uncommon Descent have jumped on the regulatory/coding DNA controversy. Well… no not really. Following the publication of an article in New Scientist that describes levels of divergence in non-coding and coding DNA between placental mammals and marsupial mammals (potentially indicating a predominance of cis-regulatory evolution since placentals and marsupials diverged), Uncommon Descent posted a entry that thoroughly misconstrues the whole situation.

A post at denialism blog tidily explains the whole mess. To sum up: the relative importance of mutations in cis-regulatory regions versus coding DNA is still unresolved. But protein-coding DNA is not the only functional DNA in our genome (or marsupials’ genomes, or anyone else’s), so calling non-coding DNA “junk” is just plain outdated. And grossly misreporting research findings while still making “scientific” arguments really doesn’t make it sound like you know what you’re talking about.

It’s just another mumbity jumbity effort from the ID camp to muddle things up. But the question is whether it’s on purpose or not. Hullabaloo suggests here that it’s an example of plain and simple stupidity. In the post itself, Uncommon Descent doesn’t capitalize on the misrepresentation of the data. But denialism blog points out that ID advocates have some sort of stake in the status of “junk DNA,” so maybe it’s a blundering attempt to twist the facts. The whole situation is rather unclear to me. I’m sure it doesn’t make sense.

For those who are bound and determined to view evolution as scandalous, here is a perfectly legitimate controversy within the discipline that just may be swelling up into a full-scale storm. The issue at hand is whether mutations in cis-regulatory regions (DNA sequences near genes that regulate their expression) or mutations in coding regions (DNA sequences that encode functional molecules) have been more important in generating the phenotypic variation necessary for diversification and adaptation. Of all the different types of DNA that make up genomes, we understand coding DNA the best. So not surprisingly, many of the mutations discovered to produce differences in phenotype—like those known to cause coat color variation in domestic cats and jaguars—have been found in coding DNA.

However, some examples of phenotypic variation map to changes in DNA surrounding the gene of interest, which control not what protein the gene encodes but how much of the protein is produced. A notable example is the bony armor in threespine stickleback fish: the difference between sticklebacks with pronounced armor and those with none has been traced to a cis-regulatory region for the gene Pitx1, a transcription factor involved in skeleton formation. Some “evo-devo” researchers who investigate evolutionary questions using these developmental biology techniques argue that striking changes in morphology, like those in threespine sticklebacks, are, in principle, more likely to be due to cis-regulatory mutations than protein-coding mutations. And thus it follows that cis-regulatory mutations must have been more evolutionarily important than protein-coding mutations in the diversification and adaptation of organismal forms.

The argument for cis-regulatory evolution is not new; this idea has garnered attention and enthusiasm since, for example, Sean Carroll published an article on the evolution of gene regulation in 2000. Criticism for this enthusiasm isn’t new either; in 2005, Jerry Coyne wrote a critical review of another of Carroll’s books, which itself was reported on in this blog. And of course myriad other articles, responses and critiques have filled the peer-reviewed and popular science literature. But the latest effort comes again from Coyne and co-author Hopi Hoekstra, in an article published in Evolution this month. In it, Hoekstra and Coyne argue that while mutation in cis-regulatory regions may be important, we don’t have nearly enough evidence to declare it the predominant vehicle for macroevolutionary change. What do you think?