Stuff like this drives me crazy:
BUENOS AIRES (AFP) – Scientists have found fossil remains of an omnivorous dinosaur in Argentina -- a missing link to the carnivores, a researcher said Monday. "It is an omnivore -- in other words it ate everything (plants and meat) -- which is the missing link between carnivorous dinosaurs and giant four-footed herbivores," said Oscar Alcober, also director of the Natural Sciences Museum in San Juan, 1,200 kilometers (745 miles) west of Buenos Aires. "This is a very important piece of the puzzle on the origin of dinosaurs," said Alcober.
Well, with all apologies to Dr. Alcober, while it may well be important---it's certainly fascinating---it is almost certainly not a 'missing link' in the sense the general public recognizes. The term 'missing link' is almost useless to science these days, and really almost the moment it was first proposed. It's not a term that the paleontologists typically use themselves. The actual PLoS article (summarized on-line here) of Martinez and Alcober referenced in the news item is entitled "A Basal Sauropodomorph (Dinosauria: Saurischia) from the Ischigualasto Formation (Triassic, Carnian) and the Early Evolution of Sauropodomorpha." Do you see anything in there about a 'missing link'? No? Well, what are the conclusions made by Martinez and Alcober? They write:
"We regard Panphagia as the most basal sauropodomorph, which shares the following apomorphies with Saturnalia and more derived sauropodomorphs: basally constricted crowns; lanceolate crowns; teeth of the anterior quarter of the dentary higher than the others; and short posterolateral flange of distal tibia. The presence of Panphagia at the base of the early Carnian Ischigualasto Formation suggests an earlier origin of Sauropodomorpha during the Middle Triassic."
Well, gosh, that conclusion just reeks of 'missing links', doesn't it? In fact, if we compare the rather breathless claim of Alcomber cited in the Yahoo! Science News above, with the rather tightly-focused conclusion from PLoS, we might well get the impression they aren't talking about the same thing at all? What, a layperson might wonder, is the source of all this double talk?
Well, the primary source of this confusion is the radical conceptual disconnect between the actual science of evolution and the popular (mis)conception of evolution. Biologists visualize evolution as a process by which populations acquire adaptations in response to local environmental change. Individuals don't evolve, populations do, and what constitutes fitness is typically situation-dependent. Evolution doesn't make creatures that are more 'fit' in some cosmic sense than those creatures that went on. Therefore, our ancestors are not necessarily any more primitive or any less well-adapted to their past environment than we are adapted for the world we live in today. We are not necessarily an improvement, and we certainly can't regard ourselves as the object of evolution based on the evidence available to us. As Gould has said, Homo sapiens is an entity, not a tendency.
Contrast that, though, with the popular image of evolution, which amounts to a paradigm of progress: 'lower' life forms rising through time to become 'higher' forms of life, culminating with (who else) 'the glory, jest and riddle of the world', ourselves. So ingrained is this image that endless variants are a regular feature of editorial cartoons:
This is just one of many examples. Why do people keep reading evolution as a principle of progress, when it manifestly isn't? Probably because they want to regard evolution favorably, and because treating evolution as 'progressive' essentially recasts it as an appealing (albeit long-discredited) way of looking at nature, Aristole's scala naturae:
So, the 'missing link' is really like a rung in the ladder shown abpve, a previously-unfilled-in piece of the puzzle, which is imagined (incorrectly) to be linear and progressive. Wonderful, except it is entirely misleading. Properly speaking, 'missing links' is a gloss for a term which is actually useful and not all that controversial within science---transitional forms. And even here the term is widely misunderstood. Alcomber and his colleagues have doubtless found an example of a fossil which has transitional features, but no scientist is saying that this particular creature, or even the population from which this fossil is found, is actually ancestral to present-day populations, or that any living organism is its lineal descendant. And yet that is almost certainly the mental image many people supply when this term ('missing link') is invoked!
Stuff like this drives me crazy:
It's early Saturday morning. Me spouse, who is currently on the coast, woke me up a few minutes ago with a call from her hotel room and now I'm awake (sigh). I didn't really feel like blogging at all, but since I'm up anyway...
Just for kicks, here's a segment of video I shot the previous Saturday when we got a three-day weekend together: while spelunking, I did a bit of plunking with some draperies on the first landing of Moaning Caverns. Please note that these are the only formations that visitors are permitted to touch, and that our tour guide previously drew my attention to the sonic possibilities during our descent.
My plan, frankly, is to eventually loop some of these sounds and use them on a song I've written called 'Endangered Species'. That will have to be some months from now at the earliest, however, as my current CD project is already spoken for.
I get lots of mail from both my district and my union (the Fresno Teacher's Association, or FTA), and a lot of it is about what they feel the other is doing wrong. I try to take all of this stuff with a grain of salt, recognizing that from time to time parties on either side tend to exaggerate for rhetorical effect.
However, a recent informational flier from FTA contains a few sentences from its President that just ring so true with me based on recent experience:
"In an era of one-size-fits-all curriculum, we are told by (the district) to individualize the material to fit our students' diverse needs. This is extremely difficult since we work in a district that doesn't provide any materials past what the grade level child would need. Many teachers have 5 or 6 different student ability levels in their class and must rely on their ingenuity to create supplemental materials to fill the curriculum void. This takes a huge amount of prep time; something that is seemingly overlooked by District administrators who feel the path to succes lies in the endless studying of data. However, no time is given to do anything with the information gleaned from the data. When the meetings are over, teachers are often assigned menial assessment tasks, or "homework". The combination of the meetings and "homework" interfere with the time to prepare good lessons."
This is painfully true for me. The district requires all Biology teachers to use the same text. Ostensibly the reasons for this are costs and equity issues, as when a student transfers from one school within the district to another. Now, I have no desire to use another text. I think our text is excellent. I just don't believe the district's main interest in these matters is equity for the students. It's about pushing for equality of outcome instead. A uniform text makes standardized assessments within the district more significant statistically, or at least easier to justify in the public square. It is well-known that the district would like to see the pacing guides already inplemented be used not merely to guide, but to direct the pace of instruction. Again, a 'one-size-serves-all' mentality not only at odds with the best practice of instructors, but on a potential collision course when issues of equity are raised.
Now, negotiating between two values with competing claims is a part of life. Think, for example, about the difference between 'fairness' and 'justice'. But, in a better world, administration and labor would share the risks and opportunities where these things are concerned. Instead, management wants standardization of curriculum and equality of outcomes and they'll attempt to hold the teacher responsible no matter what the result. If I depart from the district script in an attempt to better teach or re-teach a core concept to struggling students, I get flak. On the other hand, if I plow ahead regardless of what's in the student's best interests--which inevitably raises the failure rate---I get flak.
More comically, for the last several years the pressure to ratchet up benchmark performances to prepare for standardized tests has become all-consuming, the number one thing we hear from administration. Teach the standards! Take the benchmarks! Evaluate the data! Follow the pacing guide! The mere suggestion that I would like a little more time before I administer the test led to anonymous 'hints' in my mailbox and a supposed 'non-evaluative' visit from an administrator. But just last week, that same administrator approached me about the staggering increase in student failure rates last semester, which I blogged about previously. Again, this was an informal meeting, but the message was pretty clear: administration is worried that I might be failing too many kids and they want me to justify my practice---even though the way I'm teaching hasn't changed. It's the expectations of students that have become increasingly unrealistic.
As this article demonstrates, it is precisely the practice of the public schools that feeds these unrealistic expectations. Teachers, administrators and school districts are threatened with 'real-world' consequences for failure on standardized tests, and so we have responded by increasingly making those tests the primary focus of education. Yet these tests have virtually no effect on most student's grades, which paradoxically emphasize effort over outcome precisely because of the difficulty we have in defending any sort of objective standard for achievement. All new teachers are not very subtly advised to make sure that it is possible for students of below-average ability to earn an above-average grade based on effort.
Yes, that's irony for you: teachers are evaluated largely on the outcome of a standardized test, while the students themselves largely get through not on the basis of any sort of objective, standardized outcome, but by whether they come to class regularly and do the work. But that is a minimal standard for participation, not meeting any bar for excellence! No one would say that a teacher is excellent simply because they never took sick days and put in their forty hours every week. Why would we want students to believe that constitutes any sort of real-world performance standard?
On an earlier post, a commenter took me to task for not coughing up a reply to a request for some snippets of my CD project. I hope he or she will accept my belated apology and enjoy this little snippet of an audio from a recent recording session. This features Blake Jones, a Fresno-area musician who is laying down a few hot theremin licks while listening to the playback of a track entitled 'Little Wars':
Blake practices his own band of pop with his band, the Trike Shop. You can read more about Blake's music here!
Posted by Scott Hatfield . . . . at 11:34 PM
Simon Conway-Morris, eminent paleontologist, is a theist, and he's got (ahem) a few bones to grind with evolutionary biologists who think that they have buried God. And he has his critics, who think that his God is already all-but-buried. Meanwhile, in the middle, here I sit, profoundly unimpressed by either side's choice of target.
You might think I regard Conway-Morris as a sympathetic figure and a fellow-traveler, given that I am one of the so-called "God-botherers" in my private life. Conway-Morris has written an article for the Guardian that takes non-believers in his field to task, and PZ Mwa-ha-ha, as you might expect, has a detailed takedown here.
That Conway-Morris is motivated by theism is not immediately obvious from his tortured prose, but essentially he argues that the massively-convergent nature of much evolution argues against the radically-contingent view promoted by the late Stephen Jay Gould, particularly in his book Wonderful Life, which contains this memorable passage:
Run the tape again, and let the tiny twig of Homo sapiens expire in Africa. Other hominids may have stood on the threshold of what we know as human possibilities, but many sensible scenarios would never generate our level of mentality. Run the tape again, and this time Neanderthal perishes in Europe and Homo erectus in Asia (as they did in our world). The sole surviving human stock, Homo erectus in Africa, stumbles along for a while, even prospers, but does not speciate and therefore remains stable. A mutated virus then wipes Homo erectus out, or a change in climate reconverts Africa into inhospitable forest. One little twig on the mammalian branch, a lineage with interesting possibilities that were never realized, joins the vast majority of species in extinction. So what? Most possibilities are never realized, and who will ever know the difference? Arguments of this form lead me to the conclusion that biology's most profound insight into human nature, status, and potential lies in the simple phrase, the embodiment of contingency: Homo sapiens is an entity, not a tendency.
Now part of C-M's animus at Gould's point of view is personal, rather than professional. Many years ago Gould publicized examples of work by C-M and other paleontologists studying the Burgess Shale rather broadly because they seemed to lend support to Gould's views on contingency, particularly with regards to exotic fossils like Anomalocaris or Hallucigenia. As it turns out, the interpretation that Gould favored on the basis of C-M's earlier work turned out to be troubled, and was eventually repudiated by C-M himself. I'm not an amateur psychiatrist, and neither was the late Gould, but in a debate available on-line the latter pointedly criticized C-M in personal terms, as follows:
Conway Morris has chosen, less in this article than in his book, to be imperiously dismissive of my ideas, as if no sensible or experienced person could ever advocate such prejudiced nonsense. But he never tells us that Wonderful Life treats him, in his radical days as a graduate student, as an intellectual hero. I developed my views on contingency and the expanded range of Burgess diversity directly from Conway Morris's work and explicit claims, and I both acknowledged my debt and praised him unstintingly in my book....Conway Morris is certainly free to change his mind, as he has done. Indeed, such flexibility can only be viewed as admirable in science. But it is a bit unseemly never to state that you once held radically different opinions and to brand as benighted, in some obvious and permanent sense, a colleague who holds the views you once espoused. I do therefore object to Conway Morris's strategy of working out his own ontogenetic issues at my expense.
That's just the tip of an iceberg of emnity, but those who want more in that department can do their own research. Anyway, this essay is a brief response to PZ's critique of C-M's Guardian piece. PZ's critique has three parts: he thinks C-M writes poorly, he thinks C-M's evocation of 'convergence' as something like an explanatory principle within evolution is overblown and he has a low opinion of C-M's motives, which he reads as being all but indistinguishable from garden-variety creationism. I'll try to tackle all those points. Leave now if you're squeamish!
First of all, having read 'Life's Solution', I have to agree that in terms of style, Conway-Morris's prose often leaves much to be desired. He seems at times to write for an audience of precisely one, routinely confusing density of sentence structure with erudition. The following parody exaggerates but a little:
To wit, a certain grandeur in some of the book's baroque opacities melds an aside, however witty, with that which follows, which does not seem to.
So, I can't blame PZ for faulting C-M there. If anything, the Guardian article is in greater need of an editor.
As for C-M playing coy about his beliefs, this is also true. Time and time again I attempted to get some sense of how C-M might've felt that the results that he ascribes to convergence might've been 'built-in' to the whole system. Other than brief riffs repudiating the obvious inadequacies of garden-variety creationism, C-M says nothing you can hang your hat on. Allusions to cosmic 'fine-tuning' arguments which could be interpreted as pointing towards a certain general outcome are 'balanced' by C-M's repeated assertion that the initial conditions favoring the Metazoa are (unlike the prokaryotes) unlikely.
Finally, I find it more than a little odd that any Darwinian would believe that the case for God's demise is made one way or another by the observation that Darwin got some pretty important things right. The cutting remarks at the expense of folk like Richard Dawkins, which are also found in 'Life's Solution', largely detract from whatever scientific merit C-M's line of argument might otherwise carry. They rather smell of some mixture of professional envy and personal animus, as with C-M's running feud with Gould.
To summarize, I find C-M's prose style obnoxious and even deliberately obsfucatory, his rhetoric unhelpful and his general approach unsatisfying. PZ's critique is a marvel of clarity and brutal honesty by comparison.
But there is a point to be made here: namely, we simply don't know enough about the probability of evolving systems to draw any particular conclusions about Gould's 'tape of life'. There is simply not enough evidence to conclude, as Gould did, that if we rerun that tape, we would get a completely different outcome. Nor is there enough evidence to go with C-M, who would have us believe that life, even intelligent life after our own fashion, is reasonably convergent given the appropriate initial conditions, albeit rare. With apologies to Huxley (who I am pretty sure would agree with me), I will remain agnostic on such propositions at the present time.
I've just returned from a three-day Valentine's getaway with my wife.
Who else did you think would agree to share that much time with me? We went up to see some of California's Gold Rush towns: Columbia, Sutter Creek, Angel's Camp, Jackson, Sonora. We wandered historical exhibits, shopped, ran threw several showers with giddy laughter, and coughed up more money than I care to admit (well, more than my wife cares to admit) at a couple of casinos.
As I accepted the gaming losses without protest, my dear wife also catered to my interests without asking. She let me pop off the road in a driving rain to take pictures of a towering slate roadcut one day, and on another let me pop down to a trail that was dotted with discarded bits of unpolished marble and dolomite. I bought some new fossils from Russ Shoemaker at his store in Angels Camp, 'Stories in Stone.' I also went up and down all 234 steps, many in a tight spiral staircase, in Moaning Caverns, and (with great difficulty) soldiered through a chapter with much math in Martin Nowak's 'Evolutionary Dynamics'.
We stayed at a pair of bed-and-breakfast's, with the last one (The Foxes Inn) especially charming, cozy and pampering.
We stayed in the 'Honeymoon Suite', pictured on the right.
Their breakfast was outstanding in terms of presentation, variety, flavor and wholesomeness. I want to go back just to have more of their justifiably-famous oatmeal, and (frankly) just to put all thoughts of work and worry out of my mind.
It was a wonderful, head-clearing three days. I'll be posting pictures and videos of this soon enough!