CUTTING TO THE CHASE.....

Via James McGrath, this is a pithy summary of the real problem in attempting to discuss climate change science with a lot of folk....

No wonder NCSE has found it necessary to broaden the scope of their watchful eye, and create a clearinghouse for climate change education.

I mean, a lot of times the same fella who's arguing that climate change is a hoax, doesn't even believe that the data from 400,000-year-old ice cores is even 40,000 years old....because they think the Earth is, at most, about 10,000 years old. One set of denials supports another.

Now, it was possible once to be a science teacher and hold a fairly conservative assessment of climate change. Prior to the last two IPCC Reports, an instructor could argue with some credibility that while there seemed to be a recent warming trend in global climate, that the book was still out on whether human activity was a major factor in promoting this trend, and that more research was needed. I can say this with some authority, because as recently as 2005 this was the stance I took in my classes. I did not at any point want to overstate the science, and I was in no hurry to add any more potentially controversial material to a curriculum that already includes a healthy dose of sex, evolution and bioethical dilemmas.

But after the Fourth Assessment (2007), it was pretty clear that there was a scientific consensus. No scientific body of national or international standing dissents with the last IPCC Report. In June of 2007, the American Association of Petroleum Geologists, the last major holdout, replaced an earlier statement rejecting anthropogenic climate change with a non-committal position that reflected the views of a majority of its 30,000-odd members, most of whom have substantial experiencing working in the private sector for energy companies. AAPG's non-committal position, while a positive development, is still an outlier: after all, all of the G-8 nations scientific academies had previously endorsed, without reservation, the Third Assessment back in 2001.

So, now, I'm whistling a different tune. Ironically, while the state of the science in support of anthropogenic climate change is more settled that ever, public support for the science is less than when my teaching career began, thanks to a steady drumbeat of misinformation from various quarters, many of whom are pursuing a delaying action in the public square. So, thanks once again for NCSE for providing a framework for science educators to teach their state standards openly without fear of reprisal from those who want to suppress basic, well-established science:

BETTER LIVING THROUGH CHEMISTRY

This....is just amazing.



Back in the day, the Monsanto Corporation sponsored a ride at Disneyland, that ended with a loop song by the Sherman Brothers extolling the brave frontiers of corporate-sponsored chemistry. The ride itself was a hoot and one of my fondest childhood memories. The above video is a virtual recreation of what that ride was like, and I have to tell you, it's not only pretty accurate, it has details that I had forgotten or never personally experienced due to the way the ride evolved. For example, Monsanto eventually quit sponsoring it, and the Disney folk expunged direct reference to the company and its wares from the ride's conclusion.

This no doubt had something to do with message fatigue, but it also has to be noticed that there was a 'sea change' in public attitudes about the discipline of chemistry. In the 1950's, chemistry was seen as a beneficient fountain of modern miracles: WD-40! Nylon! ...and, especially, plastic, PLASTIC, PLASTIC from polymers derived from petroleum.

Then books like Silent Spring entered the public consciousness, and the emerging counter-culture (which Disney resisted for decades) carried with it a largely anti-scientific but emotionally powerful notion of "ecology" that carried with it a negative connotation to the word 'chemical'. Companies like Dow Chemical and Monsanto saw their public image greatly eroded by well-publicized (and, sometime, ill-founded) critiques of pollution and the unintended consequence of exposure to the dreaded 'chemicals.'

But, of course, everything is 'chemistry' in one sense or another. The field of chemistry is simply that branch of physics concerned with discovering and understanding all the different ways that matter and energy can be arranged. There is nothing inherently bad or good about such an enterprise, and it's more than a bit aggravating to see the pseudoscientific movements still with us that take, as a starting point, the position that "chemicals are bad." Only slightly less nauseating is the premise of "unnatural chemicals", as the deadliest chemicals I can think of are those that liberate free oxygen. I'd like to see somebody in the anti-vax movement or the "chemtrail" enthusiasts lambaste oxygen, or, as a kid once allegedly based a science project on, the deadly effects of dihydrogen monoxide (DMO).

WHAT I'VE BEEN DOING WITH MY LIFE (TEACHING)

My blogging has trickled to a stop, in part because I had been wondering if I had anything new to say about the main issues that motivated me to start blogging in the first place. So much has changed in my life, and yet, as far as science education is concerned, so little. Americans are still confused about the difference between science and belief, and a depressingly large number of them neither accept the fact of evolution nor the need to ensure that the theory of evolution by natural selection (TENS) continues to be taught in the public schools.

At the same time, this last semester (and the ensuing six weeks, wherein I taught summer school) has made matters come to a head. It's time for me to start blogging again, even if I don't have any substantial new inroads to report on science education in my area. It's time for me to start doing things like this again, because I am becoming bored with certain aspects of my life, including my work setting. I enjoy teaching, but I am in danger of falling into a rut. I need to make some changes. I need to do more in some areas, but in all frankness I need to give less energy to some of the aspects of teaching that are increasingly robbing me of joy and productiveness. As a friend in high school once said (in a more colorful fashion), you have to make sure the, um, screwing is worth all the...you guessed it....screwing.

So, with that in mind, I've decided to review my own job performance for the last 11 years of teaching biology and other science coursework. What happened? How did I get to Point B from Point A? Most importantly, what has changed, has it changed for the better, and what can I do about it in order to feel useful, productive and (frankly) engaged? I don't want to burn out before I'm 50. Lord knows I see enough colleagues who are just going through the motions after this point, and I would rather do something else with my life than attempt to 'fake the funk' from now until retirement. If I taught for another 11 years, that would be fine, as long as it was as interesting and rewarding as it was prior to 2008.

But I'm getting ahead of myself. The final impetus to publicly return to blogging occurred a few hours ago in my unoccupied classroom, the day after the final session of Summer School ended. I was tidying up the relics of the last few years, including....tests. Lots and lots of tests, written by me, in order to assess student performance in whatever course or courses I was teaching at the time.

That includes, in the order I taught them: Physics, Biology, Earth Science, Chemistry and Environmental Science. All of these were standards-based courses that had a state test to go with them. Three of them (Biology, Chemistry and Physics) count as laboratory science courses on the (a-g) standards for the University of California. All of them count towards my school district's requirement that students have three years of high school science. In each course, every year, I would give 9-12 unit tests which varied considerably in length and difficulty, depending in part on the subject matter, the student population that semester and the intellectual climate of the year in question. Each test typically had two versions to discourage cheating. I rarely reused tests, but typically rewrote them every year, often keeping some of the same assessment items, albeit rearrange and rewritten. Thus, each test represents a substantial investment of time in writing, and (especially in the case of Biology and Physics) rewriting.

For example, here is a shot that shows collated copies of the Physics tests that I wrote between the fall of 2000 and the spring of 2003, three years of refinement to teach the state standards in Physics. My degree is in the Natural Sciences. It's supposed to be a teaching degree, which means that I had a year of undergraduate physics coursework, plus an astronomy class. I was initially hired to teach sections of Physics and Biology with my degree, which was supposed to qualify me to teach any introductory science class in the state of California. (This was before NCLB became the be-all and end-all of teacher evaluations in this state). Anyway, if you click on the image, you'll see three years worth of the tests of which I'm bothering to keep a few copies. This does not represent all the tests I wrote, just a sample arranged in order to give me an idea what I did when, and (hopefully) help me learn from the experience.


In any and all cases, far more tests were thrown away than were ever kept. As I type this, I need to take some of these piles out to the recycling bins. By the way, the different colors serve two purposes: first, they allow me to distinguish tests within the same year from one another; second, they allow me (and my students) to distinguish at a glance which version of the test they are taking. Each clipped pile actually contains at least two different versions, sometimes (as with a semester final) three. So the above shot, just of Physics tests, actually represents about fifty (!) separate tests. This is just skimming the cream. The rest.....


....into the trash. If you do a little math, you'll recognize that this represents about 16 tests a year. When I began my teaching career, I had a little scheme all mapped out: two regular tests per each quarter, and a final, for a total of six per semester, twelve per academic year. Keep in mind that every time I'm writing a test, I'm writing at least two versions, so it's really 24 per year.

Now, I'm not claiming that each and every one of these tests is an original pearl, full-blown from the head of Zeus. In fact, after the first year, I began recycling questions. The rewriting process is an editing process. Over time, some questions seem more pertinent to the way that I actually teach, or do a better job of encapsulating some key concept and/or state standard. Also, one realizes as you go that you can do things with a test besides assess content knowledge. You can assess effort and obtain documentation about student choices. Over time, I reformatted my tests to improve their readability. I added questions with embedded graphics: charts, maps, and other images. I fussed continually not only with the general length of the test, but the relative emphasis of the various sections. From the very beginning, I have held that a simple, straightforward multiple-choice exam graded by a SCANTRON was not 'the level playing field' desired. There are always a certain number of students who are good at taking such tests, prepared or otherwise. So I would always add other types of assessments.

As you develop assessments, the inner dialogue begins: Lengthen or trim this section? Could this be reworded for clarity? Is there a concept that I am not covering well? Why do students consistently bomb this question? Should I be concerned that most don't get this question, or not? Should I reorder the section? What items to place on an answer sheet?

Hopefully the point is clear. When you rewrite tests, you are engaged in a process of assessment: assessing the course as you teach it, assessing the state standards, comparing what you've taught with what you want them to know and (sigh) what the state expects that they will know, as encompassed in the standards. If every teacher was writing and rewriting their own tests all the time in this sort of process, there would be little need for additional reflection on their own practice. This is a point that many people who are critical of 'teaching to the test' seem to miss. If you write your own tests, then teaching to the tests that you write is not mindless, but inherently self-reflective. Self-assessment through continual reinvention of your student's assessments in light of what your are teaching is far more revealing than any contrived activity mandated, top-down, by whatever hierarchy you are in, precisely because it is authentic.

The short version: While I know that there are many teachers who use the tests from the textbooks, and who simply recycle their tests from year to year, I'm not one of those people. It is those teachers whose 'teaching to the test' tends to be mindless. For me, it comes down to this: which is more likely to be an accurate and fair assessment? Drawing up a list of questions that you want to be answered, and drilling the answers into students? Or, teaching what is needed for conceptual understanding, and then crafting the assessment based upon the most recently-completed rounds of instruction?

I think you know how I would answer that question. It is an irony, then, that I have become disillusioned with the 'standards-based' reform movement's emphasis on testing. My teaching career began as these reforms were being implemented, and initially I felt I was very well aligned with that movement. The truth is, I was and remain a believer in the high-stakes test. After all, when I began my career, I intended to have 12 of them per year. Each test would take up an entire instructional period. I would give additional time at lunch and after school for those who needed it on exam days. Every test would be prepared with a Study Guide given out 2-3 days in advance of the exam date. I would almost always have a Study Session based on that Study Guide after school the day before the scheduled exam, and shamelessly bribe students to attend that Study Session. My internal logic came down to this: since my approach to writing exams involved multiple parts and continual self-assessment, I was heavily invested in the tests. Therefore, I wanted my students to be heavily invested in them. Not only did I weight them heavily, but I used significant time in the school year to prepare and administer them.

That is not, however, what most of my colleagues do. They don't invest much time in preparing or administering tests. They build what are, in my opinion, low-quality assessments that are intended to be administered in half a period, and they do so by "cutting-and-pasting" pre-fabricated questions, almost all of them multiple-choice, from the textbook or associated materials. The attitude seems to be: "Professionals have already developed questions for us to use, so why reinvent the wheel?"

Well. Duh. In order to be creative, authentic professionals yourselves. This is not to say that my colleagues aren't professionals, or shouldn't be treated as such, or that I have nothing to learn from them. Quite the contrary. I genuinely feel that in the first 6-7 years of teaching, that my colleagues were superior to me in some aspects of instruction, most notably setting up and evaluating labs and other classroom activities. I learned much that was valuable by observing them. I know that in such aspects I can still profit immensely from the experience of other veteran teachers.

I have yet, however to find another high school teacher whose tests struck me as either skilled or thoughtful. I am particularly put off by questions from the textbooks, which are invariably simplistic and misleading. And I find myself continually out of step with the agenda of most administrators and many teachers, because of the different ways in which I and others "script" the course, or as we often say, curricular sequence.

My colleagues at Bullard and throughout much of the educational system, most of them are doing their best to teach the students they are given with a series of scripts which were largely crafted for them: state standards, pacing guides, benchmark exams and departmental assessments (more on that stuff later). I, on the other hand, want to write my own script. I want the freedom to satisfy the standards following a curricular sequence that reflects my own continual self-assessment. That is what I used to do most of the time prior to the fall of 2008, and what I would prefer to do now. In my next post, I will explain why the intellectual climate within my district and my state is discouraging to me, and why I am ready to break with my past practice.

ON THE RADIO!

You can check out my gig with Alan Autry here:

http://www.940kyno.com/index.php?c=28

TALK RADIO . . . AND ARSENIC

Hello, people who care about science education! I hope you are well and enjoying the buildup to the holiday season.

As it so happens, I will be back on the Alan Autry radio program (1300 KYNO) on between 11:00 and 12:00 on Tuesday morning, Dec. 21st. Regular readers of my blog may recall my first steps into this arena, and the considerable amount of traffic and comments it generated....so it will be interesting to see if this will be more of the same. I kind of doubt it, because just today Autry has announced that he will be stepping down from the program to pursue other interests. Here's hoping that his decision will not impact my understandable desire to spread a little science mojo!


Speaking of which . . .






I've been asked to address the exciting recent finding of bacteria in Mono Lake which are not only able to tolerate that body of water's extreme salinity, but which (evidence suggests) may be able to substitute arsenic (As) for phosphorus (P) in the building of the macromolecules of the cell.

It has been shown that these bacteria, when removed from the lake, continue to grow (at a reduced rate) on media that contains arsenic, but with virtually no phosphorus. This may mean that these bacteria have worked out the trick of making arsenolipids rather than phospholipids, AT(As) instead of ATP, and perhaps even incorporate arsenate groups into their DNA rather than phosphate groups.

If so, these remarkable bacteria may be evidence of how some sorts of bacteria flourished in extreme environments in the early Earth's oceans, or how alien lifeforms on other worlds might be able to use a different chemistry. NASA, which paid for the research, is understandably keen to emphasize that point.

Or maybe not. Notice the qualifiers? As often happens in science, media accounts tend to overstate the certainty of the finding and its implications. There are other possible explanations for the data produced by Felisa Wolfe-Simon and her team, and there has been sufficient heat generated over this that Science magazine has taken the rare step of making a current article available free to the public for a few weeks here.

Could be a lively discussion with the Mayor, and it certainly intrigues me as a high school science teacher, as this is something happening in our neck of the woods, and a topic of discussion in the popular culture. It's just the kind of thing that science teachers should be prepared to briefly discuss with students who are understandably intrigued by the fact it was found nearby, and that it might have a bearing on things like the origin of life either on Earth, or on outer space. It doesn't hurt that Wolfe-Simon sees the value of promoting her own research interests: her web site is a hoot.

And you know, it is fascinating to learn about the diversity of microbes and their adaptations to extreme environments. Wolfe-Simon's work is a logical extension of recent work that established the fact that microbes are involved in the cycling of arsenic in these soda lakes. You can read about that here.

RED HOT CHILI PEPPERS!

Too awesome not to share. Jorge Cham has a wonderful comic strip about grad school called Ph.D, and he often has extended strips that discuss the state of research programs in the sciences, as when he talks about cancer or the Large Hadron Collider at CERN.

But he has outdone himself here, showing a real-life grad student doing genetic research on pepper plants at New Mexico State University:

PHD Tales from the Road - NMSU's Chile Pepper Institute from PHD Comics on Vimeo.

By the way, my alma mater (CSU Fresno) has a research program involving pepper genetics as well:

AWED BY THE GALAPAGOS

The Fresno Bee approached me a little over a month ago with the idea of doing an article about my Galapagos experiences.

That article ran in Saturday's Bee and can be viewed on-line here.

The article itself is a pastiche of quotes either collected by the reporter, Ron Orozco, or edited from observations that they asked me to submit. There were some formatting problems with the Bee article that were corrected on-line, but the paper has more still shots from video taken by yours truly. Overall, I was happy with the article.

If this is your first time visiting my blog, well, I haven't been posting a lot lately but there is lots of back material. I'm interested in promoting science education, and I hope you'll take a look at any categories that interests you. My Galapagos trip has caused me to more tightly focus my blogging on ways that promote local science education, and I have another blog to support that effort, here.

IN WHICH I DEPART

To my Colleagues, Friends and Family:

As you may know, I am taking coursework in the Galapagos, a chain of volcanic islands in the South Pacific about 600 miles off the coast of Ecuador. It is remote, but to biologists, a celebrated location due to its association with Darwin's theory of evolution. To a high school teacher like myself this represents a major investment in my own practice, and a once-in-a-lifetime sort of experience that I hope to bring back to the classroom. Without exaggeration, it represents the greatest adventure I have ever embarked on.

It is also the longest (10 days) that I have ever been away from my family in Fresno, and the furthest that I have ever traveled in my life. For someone who spent part of his childhood in Panama and another chunk in Alaska, that's saying something.

I am aware that many people have contributed to this project in one way or another, whether by a donation, thoughtful advice or encouragement. I am deeply grateful for all the support I have received, but I especially want to thank my wife, our kids and the rest of our family for helping me out. I couldn't have done it without their encouragement.

On a practical note, I leave in about seven hours from Fresno and should arrive in Ecuador sometime on the evening of the 29th. I hope to return to Fresno no later than Friday, July 9th. During much of the trip I will be in areas in which access to the Internet does not exist and cellular phones will not work. If I get access, I will try to let people know what is going on, but the reality is that I will be incommunicado 98-99 percent of the time.

Please know, however, that you will be in my thoughts and that I hope to have many adventures worth recounting.

HOLDING MY HAND OUT

Well, it has come to this at last. As you may be aware, I am planning on taking coursework in the Galapagos Islands in July. This is part of a program in which I will earn units in both the Geology and Biology of the Galapagos. Beyond making what is in effect the biological equivalent of a pilgrimage, I am hoping that what I see and experience will make me a more effective instructor in Biology, particularly as regarding evolution and natural selection.

I don't intend to stop there, however. I want to be able to document my voyage of discovery and bring into the classroom---not just my own future classes, but to the Central Valley as a whole. As you may be aware, where I teach is not exactly the most progressive place in these United States, and (despite pretty fair standards and the presence of NCSE up in Oakland) evolution education in my own County is pretty woeful.

That brings me to this project:

Evolution isn't something that's confined
to exotic locations!

Isolating mechanisms, changing environments, patterns of selection and diversification are going on throughout the world, including the Central Valley. I want to bring an awareness of what's happening right here to my students, so that they can see evolution at work in their parks, their orchards, their forests and even their urban settings.

What , for example, could possibly be more motivating to students that to learn that real-life examples of natural selection in action are be studied just a few miles away from where I teach, in Millerton Lake?

Photo: Katie Peichel, Pam Colosimo, and David Kingsley (HHMI and Stanford University)

Outstanding research by David Kingsley and his associates has documented how genetic changes in stickleback fish in different environments have led to recent speciation events in populations that became isolated when global sea levels fell during the last Ice Age. Placed in refugia that lacked the predators experienced by marine populations, the pressures to maintain the dorsal spines that give these fish their name was relaxed, and the energetic costs of maintaining these spines asserted themselves.

That's the sort of connection I want to help foster, but to make that connection especially vivid we need to relate our surroundings to the familiar example of the Galapagos, the "workshop of Nature" found in our textbooks. Doing that means creating specific content, hopefully vivid and memorable, that brings the Galapagos to the Valley---so that we can then discover the connection, in effect Finding OUR Galapagos.

That, at least, is my vision. But, I have to confess, I am going to need to some help. The expenses associated with this venture go well beyond what most individuals, including public school teachers, can easily meet out of pocket. Stepping up and making the commitment to further my education as a science teacher has been a significant investment undertaken without any institutional support, and since beginning this effort I have encountered significant unexpected expenses. To do this thing right, with the highest quality, is going to require additional support.

I am therefore asking people to contribute by clicking on the PayPal button on the sidebar of this blog, or on the blog Finding OUR Galapagos. This will allow you to make a donation to this effort. No contribution is too small to assist my colleagues and I, and you can believe me when I say that it will be well-spent, bringing high-quality science education to biology students in the Central Valley.

Thank you, in advance, for helping out as you are able.

Thank you, in advance, for helping out as you are able.

SCIENCE...OR NOT? A TALK BY RAY HALL

This talk should be right up my alley.


Many Cafe Scientifique talks are aimed at sharing the actual research of a scientist in our community with the general public. As such, they are fascinating but unlikely to become part of a high school science class. But Dr. Ray Hall's talk is part of the warp and woof of every science curriculum worthy of its name. I might even have something to contribute to this topic meself. After all, I have to teach some aspects of this in order to be effective.

This will take place Monday evening, at Lucy's Lair, starting at 6:30 PM. If you love science, and you will be in the Fresno County area tomorrow night, why not join us?

****UPDATE*****

Sadly, this is not about Dr. Hall's talk, which was excellent, or about Cafe Scientifique, which offers free science content for laypeople and is thus aces in my book.

It's about a comment left on this blog. I've traced it to one Dennis Markuze, who also goes by the name David Mabus and is a well-known Internet troll, banned at various sites (including YouTube) and who is obviously delusional. I don't mean the ordinary garden-variety delusions of (raises guilty hand) of people of faith, or even the somewhat harder-to-defend tropes of young earth creationism or climate change denial.

No, I mean truly deluded, truly in need of medical attention. The fellow believes, for example, that reptilian space aliens inhabit the Denver Airport:



No. Not joking. So apparently I shouldn't take the comments personally. He does this to anyone and everyone he thinks needs to hear about his 'discoveries.' So, with all respect to Dr. Hall, who maintained that the demarcation problem reveals a fuzzy boundary, I don't need any particular philosophy of science to determine that Mr. Markuze is beyond the pale.

YOU'VE BEEN WARNED

Have you ever wondered what a Flash-based, ironically-modern 'explanation' of science would look and sound like? What would a science documentary by Xuxa be like? Click at your peril.

THREE POINTS FOR VOX

The ever-fulminous Vox Day generously peels off a fairly long blog post in response to a comment that I left on his blog. Here's the original comment:

I invite you to read the state science standards for high school biology in California. You'll find those on pages 51-56 of this PDF file. It's true that evolution is in there, but there is absolutely no requirement to teach 'scientific history.' I admit that I give one lecture on Mendel and his experiments when I teach genetics, and one lecture on Darwin's voyage of the Beagle and how that (and the thought of others, like Malthus) influenced his thought.

Other than that, the other 178-days of instruction are pretty much the concepts and facts that you can see on the standards, which are in fact voluminous. I can't speak for PZ and Dawkins, but I assure you that I care very much about the fact that there is less time for experiments and far too much time spent prepping for the standardized tests which, under NCLB, are used by the states and the fed to rate schools.

By the way, if your looking for a way to improve science ed, then please join me in rejecting the OBAMA administration proposal to tie teacher evaluations more closely to testing. A rare offer for you and I to unite in a criticism of the present administration!

Again, check out what we actually have to teach. There's a lot to cram in 180 days, and to do it, we typically are sacrificing labs, especially the highly-instructive but time-consuming ones that take weeks to complete.

Vox's reply is interesting and wide-ranging. I can only touch on a few points (in fact, three) that might be said to fall in my area of knowledge. Vox writes:

I'm curious to know how Scott would prefer to see teachers evaluated.

This is a thorny question, in that there are political realities at work. Most teachers are affiliated with teacher's unions which tend to resist objective measures tied to student performance on standardized tests, for reasons that Vox acknowledges. Unfortunately, many unions tend to resist objective measures in general, and many educational professionals in administration and in government are so wedded to 'standards-based reform' that considering a different approach is unlikely to occur during my teaching career. I'm not punting, you understand, just acknowledging that there are practical reasons why we have the impasse that presently exists in terms of assessing instructor performance.

Having said that....I believe in assessments that focus on content, instructional practice and classroom management skills that research shows are effective and appropriate to grade level.

What makes an effective instructor? The answer to that question would have to be somewhat different for middle school and high school science instructors than, say, an elementary teacher.

Toward that end, I am in favor of developing a class of true 'master teachers' who not only have years of teaching experience, but who have demonstrated mastery of the entire curriculum within their bailiwick. For example, I have complete confidence that someone like myself could master all of the middle school and high school science standards. Why? Oh, because I've taught them all. That should be, at a bare minimum, a requirement for any individual assessing instructional performance in a standards-based course: intimate, first-hand knowledge of the standards and how to teach them.

Without any false modesty, really, people like me don't just fall off the turnip truck. There are very few people in the state of California who can say, as I can, that they have taught all four standards-based courses (Biology, Chemistry, Earth Science and Physics) multiple times. So there wouldn't be a huge number of people, initially, who would have that sort of background that (as a first step) would be essential to evaluate other standards-based instructors.

People who do have those skills, however, should be able to directly evaluate instruction. Evaluation should employ a mixture of observations, student assessments and feedback for the instructor. Districts should decide individually what the best mix is, in concert with community leaders. The process for implementing assessment should be negotiated into their collective bargaining agreements, so that individual instructors could not automatically hide behind the blanket of their union, but would have to go through a process to justify their individual practice.

Yes, it's another layer of bureaucracy, but it's a local bureaucracy I envision, not a state or federal body. And, if implemented properly, it would be a vehicle for promoting and recognizing teacher excellence as well as identifying low-performing instructors. Because the carrot that would make the stick go would be to tie performance to salary, rather than seniority.

Notice that I'm not proposing anything that would be easy, or likely to happen any time soon. I'm just describing what I think would be a better way to do things.

Vox also writes:

But I'm sure Scott also realizes that for every good science teacher who wants to push his students and expose them to actually learning how to utilize the scientific method, there are several who would spend the entire school day haranguing their students on anything from Marxism and patriarchal oppression to Genesis and Scientology if given the opportunity.

I hear these urban legends too, but I have yet to personally encounter a science instructor who does anything like what Vox is describing. Even the creationists in the science teacher ranks (and there are many, sigh) spend virtually all of their time doing their job, which is actually teaching science. (The Freshwater case is sensational, but hardly typical of creationist science teachers in my experience.)

The thing is, the opportunity to spend significant instructional time pursuing your agenda can only come at the expense of covering the standards. And, the reality is, we don't have that much time. I have an earlier post this month that explains, in mind-numbing detail, exactly why we don't have that much time.

Finally, Vox writes, with respect to a California State Standard in Biology:

"8. Evolution is the result of genetic changes that occur in constantly changing environments. As a basis for understanding this concept: a. Students know how natural selection determines the differential survival of groups of organisms."

I should, of course, be very interested to know how they know that, given that even Richard Dawkins has now admitted that the science is still unsettled on whether Darwin was fundamentally wrong about the very core of his so-called "dangerous idea".

Vox, sorry, but you're misreading this. All the standard is saying, evolution (defined as genetic change in populations) happens, and that natural selection operates on those genetically-changing populations. These are facts. It is a trivial exercise to show that populations change genetically, and that in some environments some changes offer advantages, and others don't. Natural selection has been observed repeatedly in nature selecting for some groups, and against others, and in many cases it is possible to assess the relative contribution of selection with other forces. Consider, for example, this PNAS paper on Drosophila speciation in microclimates associated with canyons.

Keep in mind that 'evolution' and 'natural selection' are facts, whereas TENS is a proposed relationship tying such facts together in an explanatory framework to account for, among other things, the diversity of life. Please recall that, like all scientific theories, TENS is never 'proved'. Theories never become facts; instead, they are vehicles that drive scientific research, adopted because they are useful and productive, held provisionally until an improved model comes along. An improved model could be either a tweaked version of the present model, or else it could be a superior alternative that proposes an entirely different mechanism.

I am sure that you appreciate that, where biologists are concerned, we are more likely to regard the former as probable. That is what makes some of the hemming and hawing by the likes of a Richard Dawkins somewhat poignant. As an ultra-Darwinist, Dawkins has long argued that TENS is the be-all and end-all of biology, and his acknowledgment that there is a limit to the confidence we can place in such claims is certainly food for thought.

But, Vox, that has nothing to do with the standards I teach. The State of California is taking a position with the scientific consensus, that evolution occurs and that natural selection can cause evolution. These are well-established positions. The State of California takes no position on the less-established, technically interesting but not-all-that-critical question of the relative importance of natural selection in accounting for every known instance of diversification.

Richard Dawkins may be personally invested in that question, but I can honestly tell you that I am not, and I have yet to personally meet any biologist terribly invested in that point of view, or anyone who denies that processes other than natural selection can lead to speciation. I suspect, in fact, that Dawkins's caveats indicate his desire not to place himself inadvertently at odds with the emerging field of evo-devo. If so, he's being smart, because evo-devo is a happening field that is providing us clues to previously-unsuspected genetic mechanisms that certainly stand to enrich the now decades-old "modern" synthesis.

As always, Vox, I appreciate not only the traffic from your site, but the flow of ideas from your head.

DOWN THE STRETCH

...of the academic year, that is, for us California high school teachers.

I haven't posted much lately. There's a reason for that.

It's called the CST's. (California State Tests) These are those all-important content-area tests that are used to evaluate school performance and---if some people at the federal level 'Racing To The Top' had their way---to evaluate individual teachers.

I won't bore you with the reasons why teachers as a group don't care for the latter proposal. The point is, like it or not, we are getting closer to the 'drill-and-kill' part of the educational process. Beginning on Monday, I have five days of instruction left before Spring Break.

That gets me started on my unit on evolution right before Holy Week. (Yes, the irony is apparent.)

Anyway, after I return on April 6th, I have at that point about nine days to complete that unit. The CST's for my district begin on the 20th, and during that time frame I'll have perhaps 4-5 days to review everything that's been covered up to this point.

And you know what? This is going to sound sad, but I am actually thrilled. This is the first year that I know that I'll have a meaningful chunk of time to prep for the test where my Biology classes are concerned. The state standards in this area are long, multifaceted and nigh-impossible to cram into the chunk of instructional time we are given. Why do I say that? Well, in the first place, in order to learn biology you need a certain amount of basic chemistry. Students in California, in particular, are supposed to learn the following in eighth grade:
In a perfect world, students retain all this information. In this perfect world, students also recall what they learned about ecosystems and food chains in the fourth grade, photosynthesis and cellular respiration in the fifth grade, plate tectonics in the sixth grade and evolution and cellular structure in the seventh grade.

But guess what? This perfect world doesn't exist, and the majority of my students are unable to correctly answer questions about what they were supposed to have learned in science in K-8, particularly Grades 4-6. Why? Because there is really no mechanism to ensure that California public schools throughly cover their own standards.

This speaks volumes about what passes for science education in the lower grades, which increasingly have been evaluated on just two things: language arts and math scores, to the point where K-8 science education is actually at risk. Read this 2007 article from the SF Chronicle by Natalie Asimov and reflect on this: as bad as things are described in this piece, this was from three years ago and nothing has changed during that time. If anything, the situation has become more acute.

Perhaps in response to that, the Obama Administration has made a proposal that the current federal guidelines be tweaked to allow states to start using assessments other than language arts and math to evaluate the progress of public schools:



Mr. President, that's music to this teacher's ears---but even if this gains bipartisan approval, it will probably be another two years before we see any implementation. There's no real help on the horizon yet.

Oh, and in addition to all that, there are things that students need which are not explicitly in the standards. Take, for example, ions---which, in case you don't know, are atoms or molecules which are not electrically-neutral, but which have an overall charge. (Here's hoping everyone knew that)

It turns out that the concept of an ion does not appear in the K-8 science standards. It is barely even hinted at in the biology standards. But, if you don't know about ions, you can't explain acids or bases. You can't explain ionic bonding, nor can you be said to really understand covalent bonding, since it involves the sharing of charged particles to complete energy levels in the various atoms. So you can't really be said to understand hardly anything that's happening at the molecular level. You can't explain the sodium-potassium pump that is such a big part of an organism's energy budget. You can't explain why nerves fire, or muscles twitch, or hearts beat.

So, the bottom line is this: I lose at least 2-3 weeks at the beginning of each year in Biology classes making sure that the critical knowledge from previous grade levels needed to teach the Biology standards is retaught. And, throughout the year, I'm going to have to spend significant amounts of time recapitulating what is assumed to be prior knowledge, but often isn't. My guess is that I lose another 2-3 weeks of instructional time to such concerns between the first day of school and the testing window.

One more thing: when I teach the Evolution portion of the Biology standards, I often encounter another problem. Most of the science instructional minutes in K-8 is taught by teachers who do not have any commitment to teaching science, much less a degree as required by NCLB for high school instructors. The vast majority of middle-school 'science teachers' in this state hired before 1996 do not, in fact, have a science or technical degree. They have been 'grandfathered' in by various means. That doesn't mean that most of them aren't reasonably competent: most are...until it comes to something that is potentially divisive, like evolution.

Please don't act shocked when I remark that, regardless of what the standards say should be taught at the various grade levels, that evolution is typically either not taught or taught poorly. Evolution is explicitly covered in the seventh grade standards, and while the word does not appear in K-6 standards, it is clear that there are items in there intended to set the foundation for future science courses. The Grade 2 standards talk about how fossils provide evidence about the Earth's past history, the Grade 3 standards reference extinction and how some extinct organisms resemble living species, etc.

If you are an otherwise-exemplary K-6 instructor who privately holds creationist views, you would probably understand that it is inappropriate and possibly illegal to teach your personal views as science. But, since your school site is not going to be evaluated by its science test scores, there is very little pressure on you to teach every science standard. How tempting it would be simply not to cover a topic that is potentially divisive and which makes you personally uncomfortable? Far easier, in fact, just to deemphasize or even scratch those lessons in particular to carve out more instructional time for the language arts and math lessons whose outcomes will be used to assess your school site performance!

Well, I'm in the high schools. I pick up the pieces on what students know and don't know, and it's my job to 'modify and adjust' instruction to fit the needs of students so that they will be able to achieve on this year's science test. So I'll do my job. But, given all the extra time lost, one would think that we be given as much time as possible to prepare and give the dreaded state tests at the very end of the school year, maximizing our instructional time.

Nope. Here's the current school calendar for my district:



We have 180 instructional days. But the CST window begins on April 19th, and the AP testing window on the 3rd of May. In practice, districts will not schedule CST testing and AP testing at the same time. So the real deadline for the CST's is the last day of the testing window that doesn't overlap the AP window.

There are 30 instructional days following the last day of CST testing at my school site. The CST's at my school site are spread out over four days over two weeks. So that is a total of 34 instructional days not available to prepare for the CST's, or 18.8 percent of the school year. Couple that with the four weeks of instruction sacrificed during the year to reteach previous standards, and that leaves just 70 percent of the academic year to prepare for 100 percent of the standards.

So that's why I feel like I'm in a 'stretch drive.' I have a limited opportunity window to prep for the CST's, and I have to bear down and make sure I give myself the time to do it. And, like I say, I'm thrilled to have more time in the past. Will this allow my students to do significantly better on the test? Who knows, but I am going to be working like nobody's business under the assumption that they can do better.

THE SECOND LAW

I have a correspondent who has brought up that old argument about evolution violating the 2nd Law. I am sorry to say that when I was young and uneducated, I knew just enough about entropy that the argument sounded plausible and science-y.

But here's what I think these days, with Wikipedia citations embedded.


Entropy is a measurement of a system's disorder, and can often be treated as a loss of information. I assume that you will agree, however, that living things on Earth are highly organized and contain much information, at least when compared with naturally-occurring inanimate objects? That is, the fact that life exists and is seemingly complex seems to violate the 2nd Law, which is an expression of entropy? At the very least, we certainly require some explanation for life's complexity!

Please notice that I have said nothing so far about evolution. It is not evolution itself that seems to violates the 2nd Law, it is merely that fact that life is complex and enduring.

Many people often assume that evolution especially violates the 2nd Law, because they assume that evolution's most likely result is greater complexity. This assumption turns out not to be correct. Evolution itself is simply populations changing over time. Sometimes the result might be more complex, some time less so. So, again, there is nothing that specifically ties evolution to a violation of the 2nd Law. This is just an assumption in the creationist literature that has not been critically examined.

So, since evolution itself doesn't necessarily contradict the 2nd Law, what does? Again, it is simply the apparent complexity of living things, diversifying over time and seemingly able to resist the universal tendency to disorder. It is the very fact of life's properties that seem to violate this law, and while evolution is naturally advanced by scientists as a explanation for life's properties, it is not evolution itself that appears to violate the law.

In fact, since mutations are 'errors' or 'mistakes', they can be thought of as a means by which information is lost. This isn't always the case, but there can be no denying that gene sequences are not perfectly copied, and that information is lost, entirely in keeping with the 2nd Law. Evolutionary biologists will tell you, however, that these mutations form part of the pool of variation on which Darwin's principle of natural selection is able to act. In that sense, evolution not only does not violate the 2nd Law, it is in a sense dependent upon it.

The question then becomes what is the source of the original order. Interestingly enough, the 2nd Law says nothing about that. Christians naturally assume that the source of the Universe's original order is the Creator, but it is important to remember that we Christians only 'know' this by faith, and that the 2nd Law is not really a theological construct that points to any faith, much less Christianity. It is simply a generalization that systems tend to disorder, and in particular that the universe is becoming less ordered all the time. Properly speaking, the 2nd Law is not a law about the Earth, or our solar system, but about the Universe as a whole.


What, then, is the source of the local tendency for living things to diversify and become more complex? The answer is simple: a surplus of free energy, most of it provided by the sun, which on the average bathes every acre in North America with about 4 megawatts of energy per hour. This is far more energy than living things can actually use, but even at 100:1 exchange rate, we are talking 40 kilowatts per hour per acre. This is more than enough energy to drive what Schrodinger called the 'negentropy', the situation of apparently-decreasing entropy.

This decrease, of course, is an illusion. Things here on Earth still fall apart, and in order to provide us with surplus energy, the Sun is busy fusing hydrogen to form helium. At some point billions of years in the future, the Sun will run out of hydrogen and other light atoms to 'burn' as fuel. At that point, the 'party' on Earth will be over, and, in fact, the solar system will largely cease to exist. So, as the saying goes, someone has to pay for that party eventually. But it is the Universe as a whole that gets the bill, not just the inhabitants of our local system. Remember: the 2nd Law is properly speaking about the Universe as a whole. A local system can experience a temporary decrease in entropy due to the availability of surplus free energy, but in the long run the total entropy of the system must increase.

Since life is flourishing here in that window of time in which there is a surplus of free energy from the sun, how life diversifies and changes over time does not violate the 2nd Law.

MYERS MIFFED, MILLER MOCKED

An article over at PZ Mwahaha's details his disappointment with another bout of one-dimensional reportage (featuring Ken Miller) allegedly at the expense of the godless.

I can't blame him for feeling that way, after being gulled by the makers of 'Expelled.' When are we science communicators going to learn to insist upon complete copies of all the raw footage and binding agreements not to misrepresent their views with creative editing before signing up for these affairs?

Anyway, I think this mess is overblown, with the perception of intellectual dishonesty such articles promote being more odious than the very real differences in worldviews between Dr. Myers and Dr. Miller.

Look. Based on several years of observation, Ken Miller is hands down the best pro-evolution debater in North America. It really isn't even close.

At the same time, based on several years of observation, PZ is for my money the most entertaining and trenchant critic of creationists in North America.*

Both are invaluable resources for me personally, and I value them for different reasons. It's a shame that we keep having this tactical debate with respect to how atheists should comport themselves.

I personally think that Ken Miller has no business complaining about the godless's desire not to be marginalized, ignored or pilloried unfairly. I'm a theist, but it is no sweat off my back if some atheists happen to be vocal in their non-belief. I don't see how it helps the scientific enterprise one bit to discourage constitutionally-protected speech.

On the flip side, I also think that many of of the commenters at Pharyngula are clueless when they attempt to argue that Miller is intellectually dishonest simply because he doesn't share some of their premises. Guys and gals, seriously. The Ken Miller I know is not your enemy, because he would never attempt to put his version of 'Darwin's God' into the public schools.

By the way, it is likely every year more people read what Miller and his colleague Joe Levine have written about evolution than any other author, living or dead---and there is nothing in their texts at all about religion one way or the other.

*****UPDATE******

Jerry Coyne was similarly a casualty of the same one-dimensional reportage. He writes thoughtfully about the whole affair here. I find myself pretty much in agreement with him the whole way, including his criticism of an argument Miller makes regarding amputees included in the original article. While I am not an atheist, I don't think a concern for 'free will' trumps human suffering. The problem of evil (theodicy) is dicier than that, and I think Miller's views as presented in the article are wanting. They are certainly going to provide more fodder for Miller's critics.

*(Sorry, Abby, but you finish a close second with your version of bitter LOLspeak)

RISK INTELLIGENCE?

Not sure precisely what this means, but PZ directed me to this interesting site which attempts to measure what they call 'risk intelligence.' I scored pretty darn high (95 out of 100):




My 'calibration curve' (in gold) mirrors pretty closely a simple linear function (purple) related to the confidence actually felt by respondents to various questions. I don't think it means that I'm smarter than anyone else, but it does suggest that I have some awareness when it comes to thinking about my own thinking process. I find that comforting, somehow. Check it out: it's simple, quick, free and thought-provoking.

THE ONION: DEFENDERS OF SCIENCE TV?

Oh. This is funny, but my goodness, only barely satire.

I've had many conversations with colleagues over the last five years or so about this, and even made this point when I appeared on Alan Autry's radio show a while back, that the quality of science programming on cable is not what is should be.

For example, the version of 'Planet Earth' that aired on the 'Science Channel' with narration by Sigourney Weaver is full of amazing eye candy, but very little science. It seems that the cable programmers wanted to put in more commercials, and the easiest way to do that was to trim all that pesky David Attenborough narration about science that's in the original out. The 11 original BBC programs track in at 550 minutes, whereas the version American audiences saw had 7-10 minutes less per episode. What a travesty.

I can honestly say that programs on the History Channel like "How The Earth Was Made" are better than a lot of stuff on the former Discovery Channel, which routinely repackages foreign footage to make repetitive, low-content junk. Hey, watch this animation for the eighth time in an half-hour program!

GRIST FOR THE MILL

A family member sends me a link to this news story about a marvelous creature, the sea slug Elysia chlorotica:

I know, it looks like a leaf. But, actually, its a mollusc, specifically a gastropod, like the snails and slugs you might find in your garden. This particular slug's green color is derived from the fact that it sucks up up intertidal algae as a food source and actually incorporates some of the captured chloroplasts into its own cells. The significance of the news item is that scientists from the University of South Florida have shown that the slug has acquired the genes to manufacture its own chlorophyll, a pigment required for photosynthesis. That is a little mind-blowing, and the best guess put forward to how this happened is a process (horizontal gene transfer) usually associated with bacteria.

Most of us have grown up knowing that plants do photosynthesis, and animals eat the plants. Plants are said to be autotrophs ('self-feeders') since they make their own food, while organisms like ourselves are described as heterotrophs ('other-feeders') since we eat the plants or some other creature higher up in the food chain based on the plants.

But the skimpy MSNBC article I was originally sent is a little breathless* when it describes the creature as 'half-plant, half-animal.' I (ahem) 'fished' around for other news coverage , and while this article is better on the science, it still uses the (misleading) 'part animal, part plant' tagline.

In the first place, algae are not plants, anymore than mushrooms are plants. While photosynthetic like plants (which are multicellular), algae as a group are simpler, the vast majority unicellular and found in aquatic environments. Algae are actually a very diverse group, more so than the plants, with many important biochemical differences, and phylogenetic studies reveals that the common ancestor of today's land plants and modern-day algae lived nearly 500 million years ago. Bottom line: algae are similar to plants in some ways, but different in others and they are not all that closely related.

In the second place, it would be just as clumsy to describe the sea slug Elysia chlorotica as 'half-animal, half-algae' . Elysia chlorotia is still a sea slug, it is still a mollusc, it is still 100 percent animal. How can I say that? Because, morphologically and behaviorally it is still defined in those terms: it is a heterotrophic, ingestive, predatory.

People will no doubt wonder if all these distinctions matter. After all, doesn't the sea slug have some algae genes? There is a subtle point that needs to be acknowledged, however. While properly speaking genes from algae could be called 'algae genes', there is nothing inherently 'algae-ish' about the genes. Genes are simply instructions to build proteins, and the fact that a sea slug appears to have acquired a recipe for building something exotic doesn't mean that it's now anything other than a sea slug.

After all, you and I both have fifty percent of the same genes as a banana. That doesn't make us 'half-person, half-plant'.

Now, some (often creationists) have suggested that the fact of horizontal gene transfer is a blow to the old 'tree of life' image in biology, that there might be something fundamentally wrong with the notion of common descent. Please. We can still draw phylogenetic trees, we just have to add some horizontal nodes to our branching diagrams:


All this does is establish another mechanism for the generation of genetic diversity in populations. If it is to be of value to any population, the incorporation of new genes must somehow enhance fitness. Natural selection will still be involved, and if the venerable image of a tree can not always be mapped exclusively to "vertical" branches, oh well. Evolution still happens!

* There are lots and lots of organisms that are not plants, but can still photosynthesize or which have little photosynthesizers living in them. Euglenoids, for example, are well-known protists that swim, they eat other microorganisms, and turn sunlight into sugars.

SCANDAL? NOT YET

A correspondent asks me privately what I think about the East Anglia email 'scandal'. Here's my reply:

Basically, I can't get excited until a major scientific publication retracts a paper based upon clear evidence of scientific misconduct.

This does happen, even though it leaves the journal with egg on its face. Science and Nature have both famously retracted papers due to fraud in recent years. One case was a high-energy researcher who had been cooking his data for years to make it easier to publish, the other was the string of papers from the South Korean lab involving stem cell research. The latter case was a national scandal for South Korea and a serious blow to embryonic stem cell research, and there were significant pressures in the Korean government and in scientific circles to look the other way and not blow the whistle.

Nevertheless, the whistle was blown, adjudication took place, papers were retracted, careers and research programs were ruined. Both of the lead scientists in question got in big trouble:

Jan Hendrik Schon, who fabricated claims about semiconductors, fled the US to avoid criminal charges. Back in his native Germany, Schon's doctoral degree was revoked and he was essentially prohibited for working with any scientific agency for eight years. He apparently took a job with an engineering firm and is simply trying to disappear from public view.

Meanwhile, Hwang Woo-suk, who fabricated claims about therapeutic cloning, was expelled by his university, defunded by the government, and serving a two-year sentence for embezzlement.

Oh, and did I have to mention that both of these gentlemen's scientific careers are over, finished, kaput? Obviously!

So the stakes are really high for individual researchers involved in scientific fraud. The IPCC reports are not, however, based upon the privately-circulated opinions of a few individuals, but thousands of published papers with multiple authors. To believe that the furor over emails seriously undermines the credibility of climate change modeling by the IPCC seriously overstates the effect of any misconduct and at this time could only be considered premature. If there is scientific misconduct, I am confident it will eventually come out because the innocent associates of any fraud have so much to lose. But this will never take place on the time scale of scandal-mongering news cycles, so chances are most people won't pay attention to whatever the real outcome is unless it can be spun for some other political agenda.

VOX RE-DUX

Everyone's favorite libertarian character (and evolutionary skeptic) Vox Dei is up to his old rhetorical tricks in a recent post, wherein he reviews an article at PhysicsBlog which is turn is based on a paper by Mark Pagel and his colleagues at the University of Reading which was published earlier this month in Nature.

Now, the original paper in question uses phylogenetic trees to compare different models for how speciation occurs, and concludes that : "....it is the natural selection element that has even less reliable scientific evidence to support it than speciation or the concept of evolution itself."

I find this latest offering from Vox to be delightfully 19th century. Vox, you are gloriously, spectacularly wrong in multiple ways on this post. Though, in your favor, you are taking reportage in an on-line 'physics' source at face value, reportage that does a clumsy and misleading job of conceptualizing another discipline.

The big problem here is in the opening paragraph: the Red Queen hypothesis proposed by Leigh Van Valen is not strictly speaking a hypothesis about how speciation occurs, but rather about the way evolutionary arms races shape evolution. Van Valen predicted that speciation should in fact be relatively constant, and that either stasis or anagenesis should be more common than cladogenesis. It is true that Darwin (not necessarily Van Valen) tended to think entirely in terms of gradual change, changes that (in his words) would be 'insensible'. As it turns out, Darwin was wrong on both points. That hardly counts as evidence that natural selection does not occur, or that the former can not lead to new species.

Now, Pagel and company have apparently applied this 'Red Queen hypothesis' rather broadly as a term for a model of speciation, but when I read the description of the model provided in the article, it doesn't sound like a description of Leigh Van Valen's 'evolutionary arms race' promoting stasis and anagenesis over cladogenesis. It sounds like a description of phyletic gradualism, which in its strictest form is not consistent with modern evolutionary theory. So, from my point of view, the article Vox cites has Pagel et al. are said to be making claims against a theoretical model, but one which is something of a 'Straw Man'.

In fairness to Pagel et al, I don't think the reportage is very good at the site Vox cites. Here's another discussion of the same paper. Would you be surprised to learn that they directly cite Pagel, and that Pagel comes to a slightly different conclusion than was previously reported? It turns out that Pagel's group actually endorses the Red Queen hypothesis of constant speciation rates, but proposes a novel reinterpretation of the data uncoupling the former from phyletic gradualism.

Anyway, rapid anagenesis within an isolated lineage can occur as a result of natural selection. As it so happens, just this evening I saw the latest episode of NOVA .


It featured a very straightforward demonstration of natural selection acting on a population of pocket mice, wherein a rare mutation conferring protective coloration in a lava field gradually becomes more widely distributed, as in the case of the peppered moth. You can watch OR download a video about the evolution of pocket mice from HHMI, here:


What makes this example particularly robust is that scientists who studied the pocket mouse populations in nature were able to determine precisely which coding genes (exons) were switched 'on' and 'off' by mutations affecting the action of regulatory genes (introns) to make the change, and how the different lineages flourished in response to different environmental pressures. In other words...natural selection!

The program ('What Darwin Never Knew') takes many of its clearest examples straight from Sean Carroll's book 'The Making of the Fittest'. I might add that the particular set of molecular 'switches' studied in pocket mice appear to be conserved across many taxa, and are typically employed in setting external coloration and pattern. A general discussion of genetic switches can be found in this interactive page from NOVA.

Want more? Check out this interactive series of pages, where you can look for start and stop codons, molecular switches, ancestral and hitchhiking segments of DNA, and other details as you 'Explore a Stretch of Code'. This is a bit older (2001-02) but still very 21st century.

Now, why do I refer joshingly to Vox's post as '19th century'? Because Vox is actually espousing a viewpoint similar to that of Darwin's contemporaries, who were persuaded by the Origin's presentation of evidence for 'descent with modification', but had serious reservations about Darwin's proposed mechanism, natural selection. Today, the situation is notably reversed amongst most creationists, who typically admit natural selection occurs and that evolution of a sort occurs within a lineage (anagenesis), but deny the large-scale 'macroevolutionary' pattern of cladogenesis and the descent from a common ancestor which is implied.

I've posted something similar in the comments section on Vox's blog and emailed him, so it would not be surprising to see the two of us go back and forth on this.