About three weeks ago, in response to my rather animated public denunciation of a presentation of Don Patton, some folk who attended Patton's presentations at Bullard High School expressed some interest in learning what the textbooks actually teach where evolution and natural selection are concerned. I promised to answer questions about the text and my curriculum, so you can expect to see many of these posts over the next week or so.
A correspondent, referencing a paper of mine*, writes:
“In the paper you state the general definition of evolution to be "change over time". This sounds to me like any form that changes/mutates (not sure if I'm using the right terms) to another similar form of equal complexity (micro-evolution), i.e., Darwin's finches, as reported by Peter and Rosemary Grant, qualifies under the general definition of evolution. Is there a different definition for the situation where one form, the coelocanth, mutates/changes into a land animal (macro-evolution)? Or is this still under the general definition of evolution?”
There are at least three potential pitfalls here, and none of them are religious in origin.
PITFALL #1: WHAT EVOLVES?
First of all, it is not an individual’s form that changes, as the brief ‘the coelocanth...changes into a land animal” would suggest. Rather, it is the frequency of alleles within a population that changes. Individuals don’t evolve; populations do, and it is truly amazing how many educated people routinely confuse changes in an individual’s form during its life (development) with changes in a population’s genetic makeup (evolution).
This is a prevalent misconception that works much mischief. For example, in the rather disappointingly-staged Ivan Reitman ‘comedy’ Evolution (it’s not all that funny, either), a whole batch of organisms changes right before our eyes, supposedly morphing in the span of a few hours from simple to complex life forms.
Similarly, as part of the Pokemon craze that peaked a few years back, a character such as ‘Pikachu’ is said to ‘evolve’ into ‘Raichu’—and pretty much instantly! The popular culture, in other words, routinely confuses evolution with metamorphosis, an amazing distortion when you think about it, but one that it is routinely accepted by both proponents and detractors of evolution alike. It’s difficult for me to overstate how much harm is done by this trope. It would be like a physics teacher having to explain, on a daily basis, that gravity is not magnetism, and it could only prosper if there was widespread ignorance about one or the other.
PITFALL #2: DOES EVOLUTION IMPLY COMPLEXITY?
“This sounds to me like any form that changes/mutates (not sure if I'm using the right terms) to another similar form of equal complexity (micro-evolution)...”
The notion of complexity is almost always misleading when considering individual cases of evolution. In the first place, what measure of complexity would you use? In the second place, regardless of which metric chosen, there is no reason to assume that evolution necessarily promotes any particular outcome where complexity is concerned.
True, populations may acquire adaptations rendering their members more fit in a given environment, but does that make the population as a whole more complex than the ancestral population from which it sprang? By no means. The ancestral population might’ve been exquisitely well-adapted to its past environment, much more so than the newly tinkered-with daughter population which is but recently responding to environmental change. In and of itself, evolution does not imply complexity.
In fact, in and of itself, evolution does not even imply speciation (the production of new species)! Evolution is best thought of as a tree with many nodes, rather than a 'ladder of progress' leading ever-upward.
The truth is that biologists don't use the terms ‘micro-evolution’ and ‘macro-evolution’ all that much, and when we do, we don’t use them in the way that the professional creationists do. The latter typically use ‘micro-evolution’ to describe the undeniable genetic changes that occur within populations, but ‘macro-evolution’ to refer to speciation events, which they seem eager to deny.
Now, this leads to an entire can of worms which is in fact religiously motivated, so I will save discussion of the alleged ‘micro/macro’ distinction for another time, but the key point is that, being undirected, evolution itself can not be said to promote complexity, nor necessarily to be in any way progressive.
PITFALL #3: IS THERE A ‘BAIT-AND-SWITCH’?
Is there a different definition for the situation where one form, the coelocanth, mutates/changes into a land animal (macro-evolution)? Or is this still under the general definition of evolution?”
A minor quibble: coelocanths and other crossoptygerian fish are not believed to be ancestral to land animals. But, yes, whether we are talking about changes that occur in a single generation or changes that accrue over many generations, we are still talking about a ‘change over time’ in a population of organisms. Unlike the people in Darwin’s day, we now know that what changes is the frequency of alleles in a population, and so the more precise genetic definition of evolution is still in play, as well.
But, at this point, an unbiased observer might not only wonder when one definition might be preferred over another, they would also wonder if there might be times when one definition is intended, and the other inferred? Or, even more sinisterly, if there might be times where evidence for one definition is misrepresented as evidence for the other—a ‘bait-and-switch’?
Many creationists are convinced that the latter is the case, because there is direct experimental evidence for the latter in contemporary populations, but none (for obvious reasons) from populations past. These creationists often adopt the pose of scientific purist, as if they have discovered some horrible methodological flaw in evolutionary biology, as if (gasp!) drawing inferences was inherently unscientific. They would have you believe that ‘microevolution’ (which they accept) is an example of proven‘operational science’ whereas ‘macroevolution’ is unproven ‘origins science.’
Again, we can discuss the particulars of that distinction at a later date. The point I just want to address is that some creationists imply that biologists are either playing a ‘shell game’ with the word ‘evolution’ in order to deceive the faithful, or that evolutionary biologists are inattentive to important distinctions where that word is concerned. In other words, we’re either lying or blind, which is not a terribly helpful stance.
For my part, I am sure that much of the problem here lies not with the science, but with how the science is presented in the popular culture. My curriculum tries to address that by being very intentional. The first definition is used when presenting the historical context in which Darwin first developed his theory, and when I give it I tell students they will eventually be responsible for a second definition which was developed in part to test the original theory. Later on, when I give the second definition, I remind students of the earlier definition and point out that what makes a theory scientific is that it can be modified or rejected in the light of new data, and that includes how words are defined.
That’s not ‘bait-and-switch.’ That’s the way science works. After all, Aristotle thought there were two forces in the universe: ‘gravity’ (the tendency of heavy objects to fall) and ‘levity’ (the tendency of light objects to rise). No contemporary physicist would be accused of ‘bait-and-switch’ just because they didn’t use Aristotle’s definition of gravity.
* I'm going to put this paper on the Net as a PDF file later this week.
UPDATE: The paper, "Show Me A Walking Fish and We'll Talk", is now available as a PDF file here. However, I should note that there is a misleading passage at the end that implies that crossoptygerian fish like coelocanths are ancestral to modern tetrapods. This is probably not the case! Rather, coelocanths and other creatures show transitional features such as choane which are believed to be derived from a common ancestor to other transitional forms, such as Tiktaalik.
5/17/2008
QUESTIONS FROM THE GALLERY
A VOTE FOR REDEMPTION
Back in March, I cast a brief vote in favor of a talented guy with a problem. The guy was a former #1 draft pick of the Tampa Bay Devil Rays. The problem: life-threatening substance abuse. My vote of confidence: I selected the undrafted outfielder to my fantasy baseball team, but my selection reflects more than mere enthusiasm for his skills. It is a modest prayer on my part in favor of the possibility of redemption.
As I type this, in a major-league career spanning 132 games, the 26-year-old, addiction-plagued Josh Hamilton is hitting exactly .300 with 29 HR and 96 RBI over 470 at-bats. And it hasn’t even gotten that hot in Arlington. There’s been only one day so far where the high there hit the 90's (May 10th). As someone whose parents live a quarter-mile away from the Rangers facility, believe me, in July, in August, the ball is going to carry. As a fan, I like Hamilton's chances as a hitter.
Sobriety is the issue. Hamilton has been clean for nearly three years now. But all of this can come unraveled at any time. I loved the man in the orange jump suit, Ken Caminiti. He was a man's man, an incredible teammate, and a professing Christian---and he's dead now.
Eric Show was a brilliant, accomplished fellow: the Padres all-time winningest starting pitcher, the holder of a degree in physics, an accomplished jazz guitarist----and he's dead, too. Don't kid yourself: drug addiction can wreck your life, no matter how smart you are, no matter how much you're loved by others. Wine is a mocker, strong drink is raging, and the cocktail of addiction mixes even less well with the high that attends celebrity.
Still, as I follow Hamilton from afar, I'm rooting for him. Not so much that he would have another multi-homer game, but that he would have one more day of sobriety. And then another. And then another. Every day that happens, he's an All-Star in my book.
5/15/2008
UCMP GOING TO COURT
What a travesty, and (one hopes) one that will be recognized as an empty, baseless claim, as I've written about before, here and here.
At issue: whether or not the UCMP 'Understanding Evolution' site can mention that some people, some religions, don't have a huge bone to pick with evolution. This is what the legal eagles are slavering about.
As I said over at PZ Mwahaha's, there's potentially more at stake here than academic freedom in the universities. If the court rules that the UCMP site is protected because of academic freedom, but does not spell out that the complaint has no merit in and of itself, then people like Larry Caldwell will continue to argue that public school teachers like myself are violating the Establishment Clause.
Why will the carnival of suits behind this action attempt to go after teachers like me? Because teachers like me:
1) direct students to the UCMP site or to NCSE, and encourage students to use these sites as resources in writing essays;
2) show the PBS documentary series 'Evolution' to their class;
3) point out that (gasp!) the author of their textbook is an observant Catholic, or that John Paul II remarked that evolution is more than a hypothesis
Remember, this bunch of clowns are fellow travelers of those folk who declined to interview Ken Miller for their film 'Expelled' because they felt it would CONFUSE people. They are happy with a state of affairs in which science is portrayed as religion's implacable foe, delighted in fact, and some of them are willing to go to court to make sure that fiction is preserved at all costs.
5/14/2008
IMPLODED
There are about 40 million evangelical Christians in the United States.
So far, in four weeks the film ‘Expelled’ has taken in a robust $7,235,324, or about 18 cents for each evangelical. Since a typical matinee ticket is $7.00 or more, even if all the box office was due to evangelicals, less than 1 in 40 evangelicals has bothered to go see this in the theatres. And this is after they offered a significant inducement to churches and schools to attend.
It's kind of a shame. I was planning on taking a group of Bullard kids to see it, but the theatre that was close to our high school dropped it after two weeks in favor of Iron Man. And why not? That film made more money than the ID-friendly film in its opening minute.
It seems fair to guess that "Expelled' will need the DVD market to turn a profit!
5/11/2008
WHAT GOES AROUND
When I was a college student, I sung in a lot of college choirs, and it was a great experience. Some of the highlights include performances back in the 1980's with the Fresno Philharmonic: Beethoven's 9th, Mahler's 2nd, Verdi's Te Deum and a concert with Dave Brubeck. Good times.
I also remember more typical concerts in the old Wahlberg Recital Hall (now rarely used by groups on campus). Selections from 'The Rake's Progress', Stravinsky's only opera. Schoenberg's 'Friede Auf de Erde', Mozart's Vesperae Solemnes de Confessore, Faure's Requiem and....a piece by Leonard Bernstein.
Anyway, my son is in a pretty fine choral program at Fresno City College and on Sunday afternoon (after Mother's Day brunch) I attended a performance of Philharmonic in which singers from FCC and CSU Fresno performed Bernstein's Chichester Psalms. The picture in the post is from the Wikipedia article, which observes (correctly) the notorious challenges posed by the tenor part in the first movement. Good thing my son is a bass!
Anyway, it was a tremendous concert. It was a great thrill to hear the thing performed with an orchestra live, and it was especially meaningful knowing that my son and I have a connection that transcends our generations by both having sung it. The accompaniment, this time, was dynamic. When I was learning the thing many moons ago, I had listened to a reasonably good recording on an LP in the old CSU Fresno library (CD's hadn't been invented yet!), where all the turntables seemed to hum at 60 Hertz, but the brilliance of the orchestral effects (and the obvious debts to Mahler's symphonies) were much better appreciated in person.
The previous conductor, Raymond Harvey, did much to raise the technical competence of the orchestra and the present maestro, Theodore Kuchar, is a real gem. The Phil musicians of my acquaintance rave about his energy, attitude, ability to communicate and technique and the local patrons like the fact that he actively sells the Phil to the community in a variety of ways. I can say in all honesty that a production three years ago of Mahler's 2nd easily eclipsed the version I was a part of two decades ago in several facets, and the orchestra (while always in full-blown fundraising mode) seems in better shape than it has been in several years.
