Science and math in the high schools: what do you need?

High school education makes a difference, but not quite in the way I’d hoped or expected. A recent correlational study looked at the effects of more discipline-specific education at the high school level on grades in college. That is, if a student took heaps of physics as a high school student, how much will it help her in biology, chemistry, and physics? We’d expect that it should help the student perform better in college physics — she has a head start, after all — but one might naively hope that better mastery of a foundational science like physics would also help with chemistry and biology. On the other hand, perhaps bulking up on biology in high school wouldn’t help much at all with physics. Let’s look and find out!

The results are a little disappointing: there isn’t much of a cross-discipline effect at all. You might be a physics wiz in high school, but it doesn’t mean you won’t be floundering in college biology. Here’s the summary chart, which isn’t particularly well-designed, but you can puzzle out the meaning. They looked at performance in three college disciplines, biology, chemistry, and physics, and correlated it with how much high school biology (orange), chemistry (green), and physics (blue) that the students had taken.

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Effect of high-school science and mathematics on college science performance. The more high-school courses a student takes in a given subject, the better the student’s college grade in the same subject will be. The average grade-point increase per year of high-school biology (orange), chemistry (green), and physics (blue) is significant for a college course in the same subject but not for a college course in a different subject. Only high-school mathematics (gray) carries significant cross-subject benefit (e.g., students who take high-school calculus average better grades in college science than those who stop at pre-calculus). Grade points are based on a 100-point grade scale. Error bars represent 2 standard errors of the mean.

Look at the first orange bar. That’s saying that students who had taken a year of biology in high school had a greater than a full grade point advantage over students who had taken no high school biology. A year of high school chemistry gave only a half-point boost in biology, while high school physics only nudged up biology scores a little bit. It’s not just that high school physics is worthless, either — look at the blue bar on the far right. High school physics was as effective at prepping students for college physics as high school biology was at prepping students for college biology. (The middle blue bar for college chemistry is a little troubling: more physics in high school hurts your grade in college chemistry. We shall console ourselves with the immensity of the error bars.)

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Oh, and the gray bars in the graph? That’s math. Math is the #1 most effective preparation for doing well in all sciences, across the board; the more math you can get in high school, the better you’re going to do in any science class you might want to take. Look at those giant gray bars — it makes almost a 2-grade point difference to be all caught up in math before you start college. Parents, if you want your kids to be doctors or rocket scientists, the best thing you can do is make sure they take calculus in high school. Please. Failing to do so doesn’t mean your kid is doomed, but I can see it in the classroom, that students who don’t have the math background have to work twice as hard to keep up as the students who sail in with calculus already under their belt.

It’s why that xkcd cartoon to the right is so perfect. (It’s so good it almost — almost — makes up for this one).

Sadler PM, Tai RH (2007) The Two High-School Pillars Supporting College Science. Science 317(5837)457-458.

A New Human

A few years ago, everyone was in a tizzy over the discovery of Flores Man, curious hominin remains found on an Indonesian island that had a number of astonishing features: they were relatively recent, less than 20,000 years old; they were not modern humans, but of unsettled affinity, with some even arguing that they were like australopithecines; and just as weird, they were tiny, a people only about 3 feet tall with a cranial capacity comparable to a chimpanzee’s. This was sensational. Then on top of that, add more controversy with some people claiming that the investigators had it all wrong, and they were looking at pathological microcephalics from an isolated, inbred population, and then there were all kinds of territorial disputes and political showboating going on, with the specimens taken out of the hands of the discoverers, passed off to a distinguished elderly scientist whose lab damaged them, etc., etc., etc. It was a mess of a story, and the basic scientific issues are still unsettled.

Now the leader of the investigators who found the specimens has written a book, A New Human: The Startling Discovery and Strange Story of the “Hobbits” of Flores, Indonesia(amzn/b&n/abe/pwll), by Mike Morwood and Penny Van Oosterzee. I’m coming to this a bit late — Afarensis reviewed it already this spring — but finally got far enough down in my pile of books to encounter it.

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The Evolving World

Feeling pragmatic? Is your focus entirely practical, on what works and what will get the job done? Are you one of those fighters for evolutionary biology who waves away all the theory and the abstractions and the strange experimental manipulations, and thinks the best argument for evolution is the fact that it works and is important? This book, The Evolving World: Evolution in Everyday Life(amzn/b&n/abe/pwll) by David Mindell, does make you sit down and learn a little history and philosophy to start off, but the focus throughout is on the application of evolution to the real world. It does a fine job of it, too.

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Ever upwards

Of course it would be Phil who would remind me: today is the 38th anniversary of the first manned landing on the moon. I remember lying on my stomach on the floor with my chin in my hands, watching TV in the way only 12 year olds can and which would nowadays leave me wondering if I’ll be able to get up again, the front door open, a summer breeze blowing through the screen, the sound of someone down the street mowing their lawns, and right there in front of me, in this ordinary day in a boring little small town, I saw these grainy echos of a human being stepping onto the moon. We can do that. It was hard, and only a tiny few of us have ever accomplished it, but here in our hands and in our minds we have this amazing power to accomplish astonishing things.

How are we going to accomplish our next miracle, do you think?

Middle World

One of the traditional ways to explain a scientific subject is the historical approach: start at the beginning of the endeavor and explain why people asked the questions they did, how they answered them, and how each answer blossomed into new potential. It’s a popular way of teaching science, too, because it emphasizes the process that leads to new discovery. Middle World: The Restless Heart of Matter and Life(amzn/b&n/abe/pwll), by Mark Haw, exemplifies the technique. Not only is it effective, but this one slim book manages to begin with a simple, curious observation in 1827 and ends up synthesizing many of the major ideas of modern physics, chemistry, and biology!

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Evolution of a sex ratio observed

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If you’ve been reading that fascinating graphic novel, Y: The Last Man(amzn/b&n/abe/pwll), you know the premise: a mysterious disease has swept over the planet and bloodily killed every male mammal except two, a human named Yorick and a monkey named Ampersand. Substantial parts of it are biologically nearly impossible: the wide cross-species susceptibility, the near instantaneous lethality, and the simultaneity of its effect everywhere (there are also all kinds of weird correlations with other sort of magical putative causes, which may be red herrings). On the other hand, the sociological part of the story seems very plausible. There is no feminist utopia, the world goes on in a traumatized and rather complicated way, and the reactions everywhere vary from crazed euphoria to a more common despair. One thing that isn’t at all implausible, and actually has been observed, is a plague that selectively exterminates males.

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Reinventing the worm

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Sometimes, I confess, this whole common descent thing gets in the way and is really annoying. What we’ve learned over the years is that the evolution of life on earth is constrained by historical factors at every turn; every animal bears this wonderfully powerful toolbox of common developmental genes, inherited from pre-Cambrian ancestors, and it’s getting rather predictable that every time you open up some fundamental aspect of developmental pattern formation in a zebrafish, for instance, it is a modified echo of something we also see in a fruit fly. Sometimes you just want to see what evolution would do with a completely different starting point — if you could, as SJ Gould suggested, rewind the tape of life and let it play forward again, and see what novelties arose.

Take the worm. We take the generic worm for granted in biology: it’s a bilaterally symmetric muscular tube with a hydrostatic skeleton which propels itself through a medium with sinuous undulations, and with most of its sense organs concentrated in the forward end. The last common ancestor of all bilaterian animals was a worm, and we can see that ancestry in the organization of most animals today, even when it is obscured by odd little geegaws, like limbs and armor and regional specializations and various dangly spiky jointed bits. You’ll even see the argument made that that worm is the best of all possible simple forms, so it isn’t just an accident of history, it’s a morphological optimum.

But what if we could rewind the tape of life a little bit, to the first worms? Is it possible there are other ways such an animal could have been built? It seems nature may have carried out this little experiment for us, and we have an example of a reinvented worm, one not constructed by common descent from that initial triumphal exemplar in the pre-Cambrian — an alternative worm.

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Common elements of eumetazoan gene organization in an anemone

We now have a draft of the sea anemone genome, and it is revealing tantalizing details of metazoan evolution. The subject is the starlet anemone, Nematostella vectensis, a beautiful little animal that is also an up-and-coming star of developmental biology research.

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(click for larger image)
Nematostella development. a. unfertilized egg (~200 micron diameter) with sperm head; b. early cleavage stage; c. blastula; d. gastrula; e. planula; f. juvenile polyp; g. adult stained with DAPI to show nematocysts with a zoom in on the tentacle in the inset; h, i. confocal images of a tentacle bud stage and a gastrula respectively showing nuclei (red) and actin (green); j. a gastrula showing snail mRNA(purple) in the endoderm and forkhead mRNA (red) in the pharynx and endoderm; k. a gastrula showing Anthox8 mRNA expression; l. an adult Nematostella.

A most important reason for this work is that the anemone Nematostella is a distant relative of many of the animals that have already been sequenced, and so provides an essential perspective on the evolutionary changes that we observe in those other organisms. Comparison of its genome with that of other metazoans is helping us decipher the likely genetic organization of the last common ancestor of all animals.

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