Philip Kitcher and I discuss “scientism”

May 30, 2012 • 6:09 am

Philip Kitcher is the John Dewey Professor of Philosophy at Columbia University in New York, specializing in the history of science. He also holds a chair in Contemporary Civilization and teaches courses on James Joyce. Philip is a past president of the American Philosophical Association and was the first recipient of its Prometheus Prize for achievements in the philosophy of science.  Along with Dan Dennett, he’s one of the two philosophers of science I find consistently cogent, readable, and thought-provoking.

In a recent issue of The New Republic (TNR), Philip wrote a critique of scientists’ unwarranted denigration of the humanities and unjustified extension into that sphere: “The trouble with scientism: why history and the humanities are also a form of knowledge.“ I posted some criticisms of that piece on this site, and there ensued an email exchange between us.  We realized that while we agree on most things, there were still a few points to iron out.  Philip then sent me the following mini-essay with permission to post it here. My own response follows his.

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WHAT RESISTING SCIENTISM IS NOT

Philip Kitcher

My essay, “The Trouble with Scientism”, has aroused a number of responses. It has made me some unlikely allies, and, at the same time, has apparently frustrated some people whom I take to be my intellectual kin.  So perhaps it is worth explaining just what I said and what I didn’t say.

One of the things I didn’t mention was religion.  Oddly, though, some of my readers have supposed that, in defending the humanities and the arts, I was making a space for “special ways of knowing”, hence, perhaps, for special ways of religious knowing.  This is puzzling: why should anyone think that the areas of human inquiry whose virtues I sing are routes to knowledge of gods, spirits, or any other sort of transcendent realm?    It is not as though my writings have been entirely silent about the supernatural.  The last chapter of Living with Darwin argues that areas of the humanities and social sciences (whose contributions “The Trouble with Scientism” champions) play an important role in debunking the thought that any of the world’s religions provides knowledge of any supernatural being.  I do hold open the possibility that future inquiry might eventually disclose something we might recognize as “transcendent” – I don’t think it likely, but inquiry has surprised us before – although allowing that is consistent with my certainty that no extant religion tells us anything about the subject.  Unlike some contemporary atheists, I recognize the contributions of those religions that are not primarily doctrinal, but founded in commitment to important values (see my essays “Challenges for Secularism” and “Militant Modern Atheism”).  Nothing in my defense of the humanities contradicts any of these positions, nor, for that matter, supports them further.

I also didn’t mention any particular targets – and this has induced the thought that I am attacking a straw man.    In fact, scientism is alive and well and living all over the place (talk to any random sample of scientists or readers of science books for a general audience, and you’ll find some champions of the positions “The Trouble with Scientism” attributes).  But perhaps it’s easier to name names.    Despite my enormous admiration for E.O. Wilson as an advocate of sane conservation policies, and especially as the premier scholar of all time on the social insects, his writings, from Sociobiology on frequently defend scientism.    Similarly, a philosopher I greatly like and respect, Alex Rosenberg, has devoted a recent book (The Atheist’s Guide to Reality) to an explicit defense of scientism.

My intellectual ally Jerry Coyne develops a related objection. Allegedly my defense of humanities and the social sciences succeeds, to the extent it does, because the areas I point to deploy “the scientific method”. (People like Rosenberg and Wilson probably disagree: they think these areas would be radically improved if they got scientific.)    Much depends on what Jerry thinks this problematic phrase means. One possibility is to say that the method involves using uncontroversial human capacities: perception, memory, inference.   f that’s the view, the notion of “science” is so thin that the declaration that “science” is the only way of knowing is trivial – surely all human knowledge is obtained by using the capacities human beings have, and Coyne and I agree on the list.  A slightly more ambitious view is that the scientific method consists in framing hypotheses and testing them against evidence.  Depending on your ideas about what a hypothesis is, and what counts as evidence, you could see historians, anthropologists, and even dramatists, painters, and composers as doing this. My view is that, if you stretch the notion of hypothesis-testing in this way, the thesis again becomes trivial. If you don’t, you debar important modes of human knowledge.

During the past few decades the detailed study of different areas of natural science has convinced historians and philosophers of science that any common “method” is extremely thin.  The methodology practitioners acquire is very different in particle physics or genetics or earth science or psychology.   If you add cultural anthropology, social history, econometrics and creative writing to the mix, the idea of some shared “method” (one discovered in the seventeenth century??) is strained indeed. Introducing some allegedly universal “scientific method” that covers all respectable inquiry is simply a way of muddying the issues.

Jerry also overlooks a major contribution to knowledge furnished by the social sciences, the humanities and the arts.   Knowledge is sometimes advanced not by arriving at some new true statement, but by reframing concepts.   As my essay argues, particular kinds of history and anthropology are very good at generating this sort of cognitive advance (besides the people I mention, think of Levi-Strauss, Clifford Geertz, Natalie Zemon Davis, and Carlo Ginzburg). The same can be said for poetry, drama, fiction, visual art, and music. The great artists teach us to see the world differently, to divide it up in new ways.  That sometimes has profound consequences for our ways of living (witness my opening example) – and it sometimes affects the ways in which the sciences are practiced.

Perhaps in 2012, it’s worth ending with a recommendation, especially for those associated with the University of Chicago. This year is the fiftieth anniversary of a book that celebrated the role of history to change images, a book that also argued for the importance of reconceptualization and recategorization (sometimes stimulated by the arts, humanities, and social sciences) at moments of large scientific change. Thomas Kuhn’s Structure of Scientific Revolutions is both a sensitive discussion of the achievements of the sciences, and a powerful antidote to the oversimplifications that fuel scientism.  Its lessons have, apparently, still not been thoroughly learned.

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JERRY’S RESPONSE

Let me first apologize if I gave the impression that Philip was, by critiquing scientism, somehow promoting religion as an alternate “way of knowing.” Philip makes clear in his essay that he doesn’t believe that, and has always pointed out the deficiencies of faith in that respect. He is, I think, an unbeliever himself.  The reason I went after religion in my original piece was not to criticize Philip, but because the “scientism” card is played much more often by religious people than by philosophers or scholars in the humanities.  Nearly all of the attacks on scientism I have seen have one intent: by showing that science has its limits, and grapples with questions inappropriate to the discipline—the so-called “why” questions—this validates the idea that there is another way of answering those questions. That way is, of course, religion.  But religion never has and never will answer those “why” questions, because there’s no way of checking whether any answer is correct.  But that is my bete noire, not Philip’s.

So let us take up the areas where, according to Philip, scientism truly does reign: in the attitude of scientists toward the social sciences and the humanities—especially the arts.  He gives some names of those who are guilty of this practice: Alex Rosenberg and Ed Wilson. While I agree with Philip about Wilson, who once said that evolutionary biology would ingest all of the humanities, I also tend to agree with most of what Alex says.  He states his views strongly and forcefully, and when you do that about things like free will you’re bound to suffer. But I don’t find Rosenberg’s writings invidious, nor do I see him as completely dismissing the value of the humanities. (It’s been a while since I read his latest book,The Atheist’s Guide to Reality, so I may have forgotten).  But in my experience (granted, this is anecdotal), many scientists do recognize the value of the humanities, and certainly appreciate the endeavors of historians, Biblical scholars, and archaeologists. In general, I find scientists are more conversant about art, music, and literature than most humanities scholars are about science. And many scientists love the arts; it should be obvious from this website that I am among them.

Further, I don’t see, as apparently Philip does, a wholesale drive on the part of scientists to wrest money from the already-impoverished humanities.  But then Philip and I have had different experiences.

And I agree with Philip that yes, some spheres of the humanities, namely the social sciences, do give us a way to find knowledge.  They do it by using the same techniques as do “real” scientists: observation, experimentation, testing of hypothesis and predictions, rational inquiry, and doubt. In fact, I have long called things like social science, history, Biblical scholarship (as opposed to theology), and archaeology “science broadly conceived.” In fact, I have said that even things like car mechanics and plumbing could be considered forms of science, for when fixing electrical problems or finding leaks, mechanics and plumbers use scientific inquiry.

Philip objects to my extension of science, saying:

One possibility is to say that the method involves using uncontroversial human capacities: perception, memory, inference.  If that’s the view, the notion of “science” is so thin that the declaration that “science” is the only way of knowing is trivial – surely all human knowledge is obtained by using the capacities human beings have, and Coyne and I agree on the list.

Well, I’m happy to reframe things like archaeology, history, and detection of leaks as “the use of secular reason,” and reserve the label “science” for “things done by scientists.” It doesn’t matter to me.  What is important is to draw a distinction between those ways of knowing that employ secular reason and the tools of science (the ones I’ve listed) and those “ways of knowing” that rely only on revelation, dogma and authority—i.e., superstition and religion.  It’s important to realize that religious people often claim that their methods are also ways of knowing, providing a portion of “all human knowledge” via “the capacities human beings have.”  In that sense, Philip is wrongly implying that I include religion as a form of “science.” After all, revelation involves perception, memory, and inference, too.

Here are a few quotes showing that theologians and believers really do think that religion can uncover objective truths about nature—often in the same way as science:

“The second mistake is about religion. The question of truth is as central to its concern as it is in science. Religious belief can guide one in life or strengthen one at the approach of death, but unless it is actually true it can do neither of these things and so would amount to no more than an illusionary exercise in comforting fantasy. . . .”

“Both science and religion are part of the great human quest for truthful understanding. . . . The claim will be that both are seeking truth through the attainment of well-motivated beliefs.” —two above quotes from John Polkinghorne

“On the contrary, religion is about the deepest of all realities. . . religion, to anyone who takes it seriously, is about what is Most Real.” –John Haught

“Both [science and theology] continue in the quest for truth.  Both continue to make claims and argue for them. A kind of alliance of stubborn truth-seeking is formed here.”   —Anna Case-Winters

“Just as scientific instruments are tested before being used in a laboratory, this ‘instrument’ for detecting the presence and activity of the Spirit of God might be validated for future first-order research on spiritual subjects.  Thus we could have scientific evidence for the reliability of religious experience.”—Nancey Murphey

It’s important, then, to realize that the faithful, both regular believers and theologians, often claim that faith is indeed a way of knowing—and one comparable to science. But their methods differ from those of historians, philosophers, archaeologists, and scientists. The “methods” of faith are not reliable ways to gain knowledge.

But I digress.  Like me, Philip doesn’t define science in either of his pieces. It’s hard for me to do that, since I see science as essentially continuous with things like history and archaeology.  I see science not as an area of inquiry that depends on a prescribed “scientific method”: as Philip and others note, there is no one “scientific method.” Science can proceed via induction or deduction, experiment or observation, or any manner of rational inquiry that produces reliable (i.e. generally verifiable and reproducible) knowledge. I prefer to think of science as an attitude rather than a method: a respect for the truth about nature and a determination to wrest that truth from obscurity by using methods that, according to most rational people, reveal what’s out there.

Philip makes much of the different ways that different sciences approach “truth.”  I agree that there is such diversity, but it means little to me so long as those methods respect honest inquiry, doubt, and the susceptibility of provisional “truths” to replication by independent observers. I don’t see what that has to do with scientism.

I want to make just two other points. First, Philip complained to me, in our email exchange, that I had neglected his emphasis on the value of the humanities in “formulating concepts”—presumably scientific ones.  As he said, concepts and hypotheses do not originate de novo, but always in a social milieu. And perhaps some of those concepts were helped along by things like the arts (Philip mentions “poetry, drama, fiction, visual art” and music”).  Sadly, he doesn’t provide a single scientific concept that was formulated with the inspiration of the arts, but I’m prepared to believe that they could be, at least in principle.  Suppose Kekulé had hit on the structure of the benzene ring by looking at a painting of a ring of monkeys holding onto each other’s tails, instead of, as the story goes, seeing that image in a dream. Then yes, the arts would have helped with concept formation.  Or suppose that Darwin, inspired by the beauty of the landscape during his famous carriage ride, came up with his “principle of divergence” (I’m making that up). Then science would again have been promoted by non-scientific ruminations.

But so what?  Those ruminations must still be tested by empirical observation, reason, and experiment.  “Concept formation” is not a way of knowing, but a way of stimulating the confection of hypotheses. Those hypotheses become knowledge only when one applies the methods of science or secular reason.

In the opening example of his TNR essay, Philip uses the bombing of Dresden as an example of how the humanities (moral philosophy) lead to some kind of “knowledge.”  But, I submit, realizing that bombing Dresden was immoral is not knowledge in any scientific sense (or even the car-mechanic sense), but a subjective judgment. Sam Harris nonwithstanding, I don’t think there’s any such thing as an objective morality: there are only things that conform to a morality that rests on subjective values (in Sam’s case, it is good to maximize well being). So no, it was not objectively immoral to bomb Dresden: it was immoral if you accept the premise—as nearly all of us do—that it is usually wrong to inflict unnecessary death and injury on innocent civilians in wartime (there is still the question of the inevitable and unplanned collateral damage that occurs in any war). Morality is not the same thing as the knowledge that science produces, though science can of course inform morality (e.g., finding out when fetuses appear to be sentient), and philosophy can help us arrive at sound moral conclusions (e.g., morality cannot come from God unless you believe that anything God deems as moral, however repugnant, is moral).

So I don’t see the humanities as of tremendous value in the formation of concepts that lead to real “knowledge,” though they could in principle inspire concepts. It would help if Philip had provided more examples.

Second, what about the arts: music, literature, and painting?  Do those provide “knowledge”? As I’ve said before, they can inspire the acquisition of knowledge, but I don’t see them as ways of knowing in themselves.  The arts are ways of communicating feelings between people, of affirming our common humanity, of making us see things in different ways.  But nobody has satisfied me that the arts actually provide real truths about the world in ways that don’t need verification by empirical observation. This argument has gone on and on, and some will disagree. Some, like Nick Matzke, think that the arts contain “truth” (his example is Handel’s Messiah). Well, perhaps the arts can convey truth that was already known by secular reason, but I’m not yet convinced that they themselves are ways of finding out anything.

In the end, I’m not sure how serious the charge of “scientism” really is. Philip gives few examples, either in his TNR piece or the essay above.  Yes, some scientists occasionally overreach, claiming that, for instance, human social interactions will one day be reducible to molecular motions (they must certainly be consistent with molecular motions, but of course also demand methods of inquiry distinct from those of physics). But my experience is that few scientists are guilty of this. Nor do I see pervasive dismissal of the humanities by scientists, and I certainly don’t hear scientists constantly denigrating archaeology, Biblical scholarship, or history.

I’d prefer to see the word “scientism” quietly shelved, replaced by more specific charges like “scientists sometimes overreach themselves” or “scientists denigrate the value of literature.” Those, at least, are charges that can be documented and discussed using evidence.  The general charge of “scientism,” slippery of definition, can’t be.  And worst of all, that charge is leveled most often by religious people, whose own methods of knowing are wholly incapable of conveying truth. But that is my issue, not Philip’s.

RIP Doc Watson

May 29, 2012 • 5:42 pm

Doc Watson died today in a North Carolina hospital. He was 89, and had recently undergone abdominal surgery.  His real name was Arthel Lane Watson, but I didn’t know that until today. Blind since the age of 1, he was still the master of bluegrass and country guitar, and the Supreme Flatpicker. He had a lovely, mellow voice as well.

I don’t know how many times I’ve listened to his music, but it’s a lot. I’ll miss him, but we’ll always have his music. Here are two pieces. The first is one of his most famous, “Deep River Blues” (this version is from 1991):

And here (from a television documentary) is an impromptu performance of “John Hardy” with Earl Scruggs, who also died this year. There are snippets of two other songs. It must be lovely to have so much talent that you can just sit down and instantly produce music of this quality.

Watson shows his proficiency at flatpicking beginning at about 1:30, and again at about 5:07.

Videos from an ID conference at Biola University

May 29, 2012 • 12:15 pm

UPDATE: Over at Sandwalk, Larry Moran, who has dispatched Jon Wells’s ID-based arguments against “junk DNA” several times (see links below), goes after this latest video.

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Know thine enemies. Uncommon Descent has a collection of videos from an Intelligent Design (ID) conference at Biola University (originally named “The Bible Institute of Los Angeles”), including talks by Jon Wells, John West, David Klinghoffer, and (God help us) Denyse O’Leary. There’s also a panel discussion.  At another site, you can see videos by Casey Luskin and Jay Richards. I believe the conference actually took place in 2010 but the videos have just appeared. I’ll put up just three:

Denyse O’Leary.  Words fail me about this talk, though if you’ve read her you’ll see that she’s exactly what you’d expect: a rambling, incoherent Catholic who is a straight-out creationist. Watch for amusement only, since there’s little substance here.  Note that at 9:15 she says that we know nothing about “stone age man” because all that remains are “a few stones and bones.” She then quotes Chesterton, Hilaire Belloc, and others to show the fallacies of Darwinism. Curiously, though, she acts beleaguered, as if American and Canadian culture were pervaded with strict evolutionary views (as she claims,  “Darwinism is the bedrock of popular culture”), Well, maybe more so in Canada than the U.S., but it’s well known that in the U.S., at least, overt naturalistic evolutionism is accepted by only a minority.

If you manage to make it through the whole talk, you get a Merit Badge for Intestinal Fortitude. With enemies like her, who needs friends?

Jonathan Wells. Wells pairs Dawkins and Collins as misguided proponents of evolution and common ancestry (what a combination!), Wells’s main claim being that nonfunctional parts of DNA (so-called “junk DNA”), do not give evidence for evolution and common ancestry. As he says,   “Much of what they call junk turns out to be functional.” And that’s true, but not all of junk DNA.  Larry Moran has taken on this claim of Wells, and thoroughly debunked it. I needn’t repeat all Moran’s critiques in this post, just go here, here, and here for a comprehensive demolition job.

I do want to say a few things, though.  First, vestigial genes (or “dead genes” or “junk DNA”) do not have to be without function to give evidence for evolution.  It’s the same, as I emphasized in WEIT, with vestigial traits. Penguins use their flippers (modifications of the wings of their flying ancestors) to “fly” through the water. They’re functional, but that doesn’t mean that penguin flippers provide no evidence for evolution. Ostriches, also flightless, use their wings in threat displays, and supposedly to shield their young from the hot African sun. In the same way, the fact that we have nonfunctional genes, even if they might do something (like regulate other genes), doesn’t mean that those genes don’t given evidence for common ancestry.  They do.  Humans, like other primates (and guinea pigs and vampire bats) have an inactivated GLO gene—the last gene in the pathway for synthesizing vitamin C—and it produces no product. Ergo we, and the other species, can’t make vitamin C.  That’s why sailors got scurvy before they realized that rations of lime juice would prevent it.

Now a creationist like Wells can say, “Well, the dead gene might do something–we just don’t know,” but (though he denies it) that’s a god-of-the-gaps argument, and one that can always be made for junk DNA. But how can he explain this:  the very mutation that inactivates the gene in humans is the same mutation that inactivates it in other primates? That argues not for design, but for common descent.  And this: the more diverged a pair of species is, the more diverged the DNA sequence of junk pseudogenes is.  The sequences of GLO in humans and chimps, for example, are far more similar than those between humans and guinea pigs. Again, only common ancestry—evolution—can explain that.

Finally, as Abbie Smith constantly emphasizes, our genome is full of endogenous retroviruses, the vast majority of which don’t do anything and aren’t thought to do anything. In fact, if they did anything they’d cause disease and cancer. They are the remnants of ancient infections.  And, curiously enough, the chromosomal location of some of these these now-harmless viruses is exactly the same in humans and chimps! How can you explain that except through common descent? ID has no explanation, though I’m sure they could confect an unconvincing one. In that sense IDers operate much like theologians, desperately buttressing a dying paradigm by making stuff up.

Okay, on with Jon:

And, finally, Casey Luskin on “Why the new atheists won’t be appeased.” He presents a rogue’s gallery of accommodationists, including Eugenie Scott, Michael Ruse, and Chris Mooney, and of atheists who criticize accommodationists, including Richard Dawkins, Jason Rosenhouse, P. Z. Myers, Sean Carroll, and me.

His account of the tension between atheists who are accommodationists and those who aren’t is actually pretty accurate, as is his argument that the New Atheists won’t be appeased by any solution that comports science with religion (i.e., NOMA or theistic evolution).  His conclusion? That religious people shouldn’t capitulate to evolution in any way, because it won’t stop the New Atheist war on religion.

Luskin is probably right here. That war won’t stop until people keep religion to themselves and stop trying to force it down the throats of their children and of the rest of society by trying to make their religion into law, social policy, or universal custom. Religion is far more dangerous than creationism for the same reason that influenza is far more dangerous than a sneeze: the former includes the latter, but much other bad stuff as well.

h/t: Michael

Readers’ wildlife photos

May 29, 2012 • 8:00 am

When I opened my email this morning, I found that reader Ivar Husa had sent me a group of wonderful photos of predatory birds. I’ll put up just four of them for now, along with his commentary. Note that the owl photos are hot off the press!

As always, click them to enlarge.

These screech owlet [Megascops] pictures were taken this morning, and the little guys fledged only a few days ago.

The Swainson’s Hawk [Buteo swainsoni] pictures were taken Saturday, and all are of the same bird.  The difference in appearance (color) is attributable to the fact that the upper surfaces were illuminated by direct sunlight, where the lower surfaces by reflection from the ground, which was dry and light brown.

Here is a ferruginous hawk image [Buteo regalis] I took a couple of weeks ago at Malheur National Wildlife Refuge. My favorite picture of the month.

Pictures were taken with a (new as of Thursday!) Canon 5D Mark III camera using a Canon 100-400mm lens.

IDiots once again justify their name

May 29, 2012 • 5:07 am

They go after me a lot at the Uncommon Descent website, a vehicle for intelligent design [ID] creationism, and I usually ignore them.  But their latest tirade is so ludicrously ignorant that I have to single it out. Here it is in full:

What a thicket of ignorance we must chop through here!  My response is fivefold:

1.  To change something like a cat into something like a dog through artificial selection involves modifying not just its morphology, but its physiology, its brain, its neurology, and its (hard-wired) behavior.  That would take a gazillion generations of artificial selection.  I have no doubt we could do this had we thousands or tens of thousands of years to do that kind of breeding, but a) we haven’t because b) nobody’s interested in doing that.  Nevertheless (go to #2),

2.  Artificial selection clearly has created forms that, if found in the fossil record, or if you saw them and didn’t know they were products of artificial selection, would clearly be regarded as different species.  Here’s what humans have done to the wild mustard in just a short span of time:

All seven descendant vegetables have the same common ancestor, and were bred for various traits (the odious Brussels sprout, for example, for small unopened heads). Does anybody doubt that if we found fossil impressions of these, or saw them growing as wild plants in nature, they’d be regarded as different species, or even different genera?

And then there are these:

As I document in WEIT, there is much more variation among living breeds of dogs—artificially selected within the past 10,000 years at most—than there is among the wild species of canids in nature.  If dog breeds like the two above were found in the fossil record, they’d be regarded at least as different species, or even different genera (remember that Australopithecus and Homo are different genera).  That’s a remarkable transformation in a short period of time.

Now I don’t regard the different breeds of dogs as biological species in the sense that, by breeding between different pairs (in the case above, mating the small dog to a slightly bigger dog, and its hybrid to an even bigger dog, and so on), you could conceivably mix the genes of any two breeds, and that miscibility is the hallmark of “biological species”. But that’s only because breeders have not selected for reproductive incompatibility between breeds, but for morphological and behavioral differences.  We can’t test the ecological differences between breeds (though a Chihuahua and a mastiff surely are completely isolated sexually), but it would take longer to get reproductive incompatibility via hybrid sterility and inviability, which normally result from the interactions between many genes. Artificial selection doesn’t usually create that kind of extensive genetic change.  Nevertheless (go to #3),

3.  Researchers in the lab have successfully created reproductive isolation between forms (“species,” if you will) via artificial selection.  This has been done in several studies of Drosophila (see my book with Allen Orr, Speciation).  In fact, one experiment by Bill Rice and George Salt produced almost complete ecological isolation between two sublines of a single species (D. melanogaster) within only 30 generations of selection—roughly a year in the lab. That’s remarkable, for, as Rice and Salt say in their paper, “One of the principal difficulties with the study of speciation is that it occurs quite slowly on a microevolutionary scale, despite its apparent rapidity in the fossil record.”

Further, as I also documented in WEIT, botanists have created new plant species in the laboratory through polyploidy, precisely mimicking a process that occurs often in nature. (Anywhere between 2 and 10% of new plant species form through polyploidy, and others arise through diploid hybrid speciation, a process also duplicated in experimental studies of plants). We’ve even made, in the lab, the same species that have arisen in nature, simply by crossing the same two parental species that gave rise to the new polyploid species in the wild.

4.  And, of course, there are all those transitional forms in the fossil record showing that, despite the IDiots’ objections, new genera, families, and even orders have arisen through natural selection. Here’s one such transformation—the evolution of whales from a terrestrial artiodactyl (even-toed ungulate) ancestor:

We have all of those transitional forms, and they occur in the order given.

Here’s a likely starting point, the putative ancestral form Indohyus, a small, deerlike creature with many features that show both semiaquatic behavior and morphological adaptations that could be precursors to those of modern whales,

Artwork by Carl Buell

Here’s one descendant:

Humpback whales

How long did this transformation take? Only eight million years! Remember that humans are only five or six million years removed from our common ancestor with chimps, and the difference between ourselves and chimps (in terms of morphology) is far less than the difference between Indohyus  and modern whales.

And there are, of course, the many transitional fossils between fish and amphibians (e.g., Tiktaalik), between amphibians and reptiles, between reptiles and mammals (the so-called “mammal-like reptiles”), and between reptiles and birds. Oh, and also between hominins in the lineages spanning Australopithecus to modern humans. But IDers don’t like to talk about that transformation.  Yes, Jon Wells and Michael Behe are African apes.

5.  The unknown IDer who wrote the screed above claims that I don’t get to decide what is or is not a serious objection to evolution.  True—I don’t, not by myself.  But the scientific community does, and that community does not include the religiously-motivated proponents of ID.

Further, “what is objectionable to others” is not the criterion for what we consider a serious problem with evolution. When a serious scientist like Steve Gould asserts that the pattern of evolutionary change is jerky rather than gradual, we pay attention.  When religiously-motivated creationists like those at the Discovery Institute argue that major evolutionary transitions can’t occur because we haven’t bred a cat into a dog, we don’t pay attention.  That’s because that argument was already debunked long ago—any natural history museum instantly shows its error.  For the same reasons we don’t need to pay attention to the arguments of Holocaust deniers and flat-earthers.  The people who determine what is a serious objection to a well-founded scientific theory are other scientists, for that’s who we listen to when judging the merit of our own results.

And by “other scientists,” I don’t mean Bible-thumpers with Ph.D.s, like Michael Behe. Their motivation is not the honest pursuit of truth, but the glorification (and verification) of God by debunking His most powerful enemy: natural selection.

Benjamin Carson’s commencement address at Emory

May 28, 2012 • 11:46 am

I’m posting a video that you needn’t watch except for the first couple of minutes, and I do this just to make a record.

A while back I posted an interview with Ben Carson, a famous pediatric neurosurgeon at Johns Hopkins who is also a Seventh Day Adventist and an undiluted ex nihilo creationist.  Emory University in Atlanta, Georgia chose Carson as this year’s commencement speaker, and there was a petition by Emory students and faculty protesting Carson and his stupid views on evolution (and on the supposed immorality of nonbelievers).  He was chosen anyway, of course, and the video below shows his commencement address.  He avoided any real mention of creationism, of course, for that would have been a huge embarrassment to both him and—especially—Emory, though he did refer obliquely to his interview, saying the following starting at 3:07:

“Let me just at the outset say that I know that there was some controversy about my views on creation and somebody thought that I said that evolutionists are not ethical people. Of course I would never  say such a thing and would never believe such a thing nor would anybody with any common sense; so, you know, that’s pretty ridiculous. But any rate, enough said about that.”

You needn’t watch beyond that; his talk is incredibly boring, tedious and trite. It winds up extolling Carson’s own prowess as a surgeon and referring, of all things, to the composition of the National Anthem—our flag was still there! It’s a model of how not to give a commencement address. I bet that Emory still regrets choosing him because of the stream of soothing pablum that issued from his mouth. (Look how bored everyone on the dais looks!)

At any rate, Dr. Carson was not 100% truthful in his disclaimer about the ethics of evolutionary biologists. Look what he did say in his interview:

Ultimately, if you accept the evolutionary theory, you dismiss ethics, you don’t have to abide by a set of moral codes, you determine your own conscience based on your own desires. You have no reason for things such as selfless love, when a father dives in to save his son from drowning. You can trash the Bible as irrelevant, just silly fables, since you believe that it does not conform to scientific thought. You can be like Lucifer, who said, “I will make myself like the Most High.”

Can you prove evolution? No. Can you prove creation? No. Can you use the intellect God has given you to decide whether something is logical or illogical? Yes, absolutely. It all comes down to “faith”–and I don’t have enough to believe in evolution. I’m too logical!

His disclaimer is verging on a lie, for he averred that there is no reason for those who accept evolution to be ethical, and argued that their behavior is based on their “own desires.”  Are those “desires” always consonant with God’s will? I doubt that Carson thinks so. . .

Well, watch if you wish: it’s only marginally more interesting than watching paint dry.

Birds may be paedomorphic dinosaurs

May 28, 2012 • 9:03 am

In the last few decades we’ve realized that birds descended from theropod dinosaurs, and that the evolution of feathers preceded the evolution of flight. Indeed, many biologists still consider birds to be dinosaurs, since the group “dinosaurs” leaves out some of the descendents of dinosaurs—birds. Regardless of whether one adheres to this convention, we know from genetic and fossil evidence that birds are united with reptiles in one group: the Archosauria, which includes the common ancestor of crocodilians and birds, and all the descendants of that ancestor up to and including modern birds and crocodilians. That means that crocodilians are the living reptiles most closely related to birds (if, that is, you don’t consider birds to be reptiles).

Comparing birds with archosaurs, then, can tell us something about the evolutionary changes that produced our feathered comrades.  And this is what was done in a new paper in Nature by Bhart-Anjan Bhullar et al. What they showed is that the evolution of certain features of birds that distinguish them from their reptilian relatives, namely their large heads, eyes, braincase, and beak—probably evolved through paedomorphosis.  Paedomorphosis is the evolutionary process in which a descendant retains the juvenile state of an ancestor, retaining certain juvenile features of the ancestor into adulthood and reproductive age.  Paedomorphosis is one example of heterochrony: the process (discussed by Steve Gould in his book Ontogeny and Phylogeny) whereby evolution operates by changing the timing of development.

The classic example of paedomorphosis is the axolotl (Ambystoma mexicanum), a Mexican salamander that becomes sexually mature while retaining the juvenile features that are lost when other salamanders mature, including the gills and the caudal fin along the back:

In the new Nature paper, the authors realized that the juvenile stages of ancient archosaurs resembled the adult stages of birds, their descendants, implying that perhaps the evolution of birds involved a process of heterochrony.  Birds show smaller snouts and bigger eyes and braincases than those of their adult archosaurian relatives, but young archosaurs have the same big heads, big eyes, and short snouts as do adult (and juvenile) birds.

Here’s  figure from the paper showing the difference between juveniles and adults of three living and fossil species: a crocodile (b), a primitive dinosaur (Coelophysis; c), and the famous Archaeopteryx (d; a stem group bird, known in Darwin’s time but now realized to be a transitional form between dinosaurs and birds).  Note the similar change in morphology between adult and juvenile in the alligator and dinosaur, but the general retention of juvenile morphology in Archaeopteryx:

(from the paper): b–d, skulls of selected archosaurs: Alligator 46-day embryo (b, left) and adult (b, right); Coelophysis (primitive dinosaur) juvenile (c, left) and adult (c, right); Archaeopteryx (stem-group bird) juvenile (d, left) and adult (d, right).

To show this pattern statistically, the authors did some fancy manipulations known as Principal-Component Analysis (PCA), parsing out those groups of morphological changes that unite related species. To do this they used both juveniles and adults of ancient archosaurs and theropods, modern birds, and alligators.  I needn’t go into detail, but what they got was confirmation of the impressionistic pattern shown above: archosaurs (including alligators) all undergo elongation of the face, diminution of the eye orbit, and reduction of the neurocranium during development.  Modern birds don’t change nearly so much, and early (fossil) birds change, as expected, in an intermediate way (for example, they undergo a bit of skull elongation). As the authors note:

Evidence for heterochrony is clear. Whereas adults of taxa distantly related to birds (non-eumaniraptorans) cluster together, basally branching bird relatives (eumaniraptorans) cluster with the embryos and youngest juveniles of other non-avian archosaurs (Figs 2 and 3), with the more crownward avialan Confuciusornis [an early bird] nearly identical to embryos and particularly close to the perinate enantiornithine (Figs 3d and 4).

The figure shows the configuration of the embryonic alligator skull, in green, superimposed on the adult alligator skull in red to the left and on the adult skull of the primitive bird Confuciusornis to the right. You can see how much more the the juvenile alligator resembles the adult bird than the juvenile alligator resembles the adult alligator. It’s hard to avoid the conclusion that, during the evolution of birds from their reptilian ancestors, evolution acted to retain the reptilian juvenile skull into adulthood.

Here, by the way, is a wonderful fossil of Confuciusornis, showing its paired tail feathers, and a reconstruction of what the adult looked like:

So maybe birds’ heads evolved simply by stopping the genetic changes that made the heads longer (and the eyes and braincases relatively smaller) during development of their ancestors. Why would evolution act this way? One answer seems obvious: birds need to rely heavily on vision to fly, and they need large brains to harbor the vision centers as well as the neuronal apparatus enabling them to fly.

Note that the postcranial skeleton (the rest of the bird) shows no signs of padeomorphosis. Indeed, some features of the bird body are peramorphic with respect to dinosaurs: that is, they seem to show an extension (rather than a truncation) of development past the adult stage.  The authors say that’s okay because the brain is modular (i.e. genetically independent) of the rest of the skeleton, and can evolve independently, so the paedomorphosis could have involved genetic changes affecting only the skull.  Something similar happened during human evolution: as we can see from our early australopithecine relatives, our postcranial skeletons evolved much faster than our cranium. Lucy, for example (an A. afarensis) has basically an apelike skull sitting atop a skeleton which is much more similar to that of modern humans.

There are other things in the paper that will be of more interest to specialists (e.g., when the various stages of paedomorphic change occurred and what happened with the beak), but I’ve given enough, I think, to show that once more an intriguing evolutionary hypothesis was sitting under our noses all along. Juvenile archosaurs have been around for years, but nobody thought to compare them to early and modern birds.

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Bhullar, B.-A. S., J. Marugan-Lobon, F. Racimo, G. S. Bever, T. B. Rowe, M. A. Norell, and A. Abzhanov. 2012. Birds have paedomorphic dinosaur skulls. Nature, advance online publication, doi:10.1038/nature11146.