MISSING LINKS, OR MISSING THE POINT?

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!

ROCK MUSIC FOR US NIGHT OWLS

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.

COMPETING AGENDAS

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?