Tuesday, February 7, 2012

Doubt and dogmatism in science -- questioning natural selection

Through no fault of his own, a friend of ours finds his written words being used (or rather, abused) by the ID community.  Again.  This has happened to us from time to time as well, so we thought we'd address it here.  Not the actual arguments, which we have no interest in, but the misconstruing of what scientists say, or clearly mean. 

Adam Wilkins, a biologist and long-time very thoughtful editor of BioEssays, a leading biology journal, recently published a well-considered review of a new book by James Shapiro, Evolution: A View from the 21st Century.  Adam reviews the book favorably in general as a thoughtful one that those seriously interested in the nature of evolution should read; but he takes widespread exception to the author's view, taking him to task for writing that natural selection may be less important than most biologists would accept.

Adam is not the first reviewer to take Shapiro to task for this. And, probably because he relegates natural selection to a minor role, Shapiro has been assumed to be an IDer by some, including some people in the ID community.  This right here means there's a problem -- if a biologist can't question accepted wisdom in evolutionary theory, this makes evolutionary theory a dogma, just like ID.  Science should always be questioning itself -- that's how knowledge is built and expanded upon.

But, giving succor to ID is not Shapiro's intention.  This is clear from the 'debate' he has with IDers, which we won't even link to because it's tiresome, and really not much more than a clash of ideologies (you'll find it anyway, if you really must).

But, after this rather fruitless 'debate', Adam, or at least his review, gets pulled into the fray.  Adam's piece was published in Genome Biology and Evolution in January.  And the authors of the post believe it's a gotcha moment, saying that Wilkins admits something that few 'Darwinists' (and yes, that's a slur) will, which is that "a growing body of scientists" are starting to question the "alleged power of Darwin's natural selection to create the world of life that we see."

Yes, Adam does say that there are biologists who feel that the role of n.s. has been overstated (and yes, you've seen that here on MT, in fact).  But, he absolutely does not include the 'therefore' that's implied -- therefore, if n.s. didn't do it, a designer did.  The gotcha quote they pull from the review is this:
…the book’s contention that natural selection’s importance for evolution has been hugely overstated represents a point of view that has a growing set of adherents. (A few months ago, I was amazed to hear it expressed, in the strongest terms, from another highly eminent microbiologist.) My impression is that evolutionary biology is increasingly separating into two camps, divided over just this question. On the one hand are the population geneticists and evolutionary biologists who continue to believe that selection has a ‘creative’ and crucial role in evolution and, on the other, there is a growing body of scientists (largely those who have come into evolution from molecular biology, developmental biology or developmental genetics, and microbiology) who reject it.
Adam's following paragraph draws their scorn. 
The arguments from paleontological evidence for the importance of natural selection largely concern the observed long-term trends of morphological change, which are visible in many lineages. It is hard to imagine what else but natural selection could be responsible for such trends, unless one invokes supernatural or mystical forces such as the long-popular but ultimately discredited force of “orthogenesis.”
Obviously this draws scorn, because invoking the supernatural is exactly what IDers do.  But, equally obviously, to a biologist such as Adam, that's not an explanation.  Adam of course was writing for biologists, and for the overwhelming number of biologists evolution is a fact of life.  He wasn't writing with creationists/IDers in mind.  If he had been, he might have restructured his argument somewhat, but he still wouldn't have hidden the fact that there are disagreements among biologists about the strength or predominance of natural selection as a force in evolution.  The disagreement doesn't make it false.  It makes it science.

For biologists, for whom not a shred of evidence collected in the last 150 years has called into question the idea that all of life descended from a common ancestor that lived nearly 4 billion years ago, this kind of disagreement is arguing around the edges. But for an ID adherent, any kind of disagreement within the fold must mean that, therefore, evolution didn't happen.

We and other biologists don't question that natural selection can occur, or that it does occur, but ask when, where, how, how strongly, and how systematically it occurs--and how we can know which is which.  We ask how it works in general or in specific instances relative to other factors that can lead to differential proliferation of variation, or of the way genetic and other transmissible variation arises and works.  That is totally different from asking whether natural selection or Divine intervention account for life, which is not what legitimate science does.  Science is only one way to know, but it rests on observable causation in the material world only.

We could put this another way.  If it were somehow possible to show--to really show--that Divine intervention were the explanation, or that Jesus was divine, or that Mohammed really did get his inspiration from the Angel Gabriel, or that ants had souls, any sane scientist would love to be the one to do that.  His or her reputation would dwarf even Darwin's!  But that's simply not the message the material world gives us.  Even if natural selection were somehow shown to be totally wrong, it would provide not a scintilla of evidence for creationist explanations.  It would just say we've been accepting an incorrect theory and have more work to do.  That is not a threat to science, even if many scientists do cling too tightly to simple explanations for complex things.

There are separate worldviews operating here, and, even if IDers actually understood the science, their fundamentalist view of the world still prohibits questioning their dogmatic view, creationism.  And this is why something like Adam's review can be taken in vain -- IDers assume that if scientists disagree, that's a crack in the religion of evolution.

But evolution isn't supposed to be a religion.  Scientists are supposed to question what they know.  Jim Shapiro's questioning of the pre-eminence of natural selection in evolution is perfectly valid science, and will either stand the test of time, and questioning by other scientists, or it will fall.  But it doesn't mean he sees the hand of a watchmaker behind every complex living thing.  It means he thinks evolutionary theory hasn't yet explained everything.


Holly Dunsworth said...

This is terrific. So timely in the semester too!

Ken Weiss said...

Well, then, you may like tomorrow's, too:
Called 'Reducible complexity'

Holly Dunsworth said...

I know you'd rather not link the ID posts but would you maybe reconsider?

Anne Buchanan said...

Just because it's you, Holly. Here's the link to the discussion of Adam's review. You can follow links from there.

Hollis said...

Thanks for the very interesting post, especially since I just finished this review by Shapiro on mobile elements and evolution: (http://www.mobilednajournal.com/content/1/1/4)

It seems to me the new thinking is not about the comparative roles of natural selection vs. genetic/epigenetic “innovation”, but rather the nature of the latter. We used to assume that small infrequent changes in DNA were the underlying basis for trait change, that mutations in general would be detrimental. Now we see that there is a much richer store of material to work with, including a lot of “neutral” variation, some of which may be useful in the right place and at the right time. Also, there is enough redundancy and robustness in the information system that some (many?) changes can be accommodated without affecting the phenotype. But in the end, if change results in a lousy phenotype, the organism won’t survive to reproduce, so natural selection still operates.

In the context of the old thinking, variation/innovation were underrated, under-appreciated; maybe natural selection now looks overrated as a result.

Ken Weiss said...

Sounds about right to me. We did a series on life as a polymer phenomenon recently, which was relevant, and GWAS shows the complexity you refer to. As a kind of new twist on old vinegar, tomorrow will further today ('Reducible complexity').

People want simple answers. People cling to old ideas they learned in school, and so on. But we have a wealth of data to support the view you expressed.

Hollis said...

I used to work for one of those people! Actually, it was because he was so vested in the old model that he didn't want to hear the news, whereas I was so excited about the news :) finally had to quit, it was that much of a problem.

Ken Weiss said...

Truth be told (and why not?!), we are senior enough (and tenured) not to have to worry about what others think, so long as they don't feel we misrepresent things out of not understanding them.

We have been funded, and currently are involved in a 'mapping' study that we want to use to document the nature of the complexities. Our views as we express them in MT are born out of experience rather than any kind of a priori ideology or politics: we used to feel these things had more promise than we do now, and experience has led us to think about the nature of uncertainties in science, and ones people simply don't want to face because of the threat to business as usual.

It makes one be accused of being anti-science, when in fact it's the opposite.

Hollis said...

a final (ha!) reply -- go for it! (and keep posting :)

Holly Dunsworth said...

Ditto. :)