SciBlogs

Archive November 2011

a follow-up (from a new blog) Alison Campbell Nov 30

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Over on ‘of trees and birds and other things’ Jarrod points out why it’s not a terribly good idea to base your view of a scientific issue on a single story in the popular press… (& hat-tip to David Winter on the atavism, who alerted me to this new evolutionary blog!) For the teachers & students who read my blog: Jarrod has an interest in forest ecology & his research area is evolutionary ecology, so I think it will be well worth dropping over to his place from time to time :-)

PS apologies for the original ‘dud’ link – all fixed now :-)

what about archaeopteryx? Alison Campbell Nov 21

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As a distraction (or should that be ‘procrastination’?) from what’s currently filling up my diary (ie processing student enrolments), I’ve decided to look at another of those ‘science’ statements from the school documents I linked to in my last post. “What about the archeopteryx?” they ask. Well, what about it? This, from their webpage:

The archeopteryx is an extinct, unusual bird. Two fairly complete skeletons have been found in Europe.

Correct as far as it goes – but there are actually eleven specimens, including an isolated feather also attributed to Archaeopteryx. Interestingly, one of those specimens was originally identified as the small maniraptorian dinosaur Compsognathus on the basis of its skeletal remains (its feathers were poorly preserved & not noticed by the original excavator).

Unlike “modern birds” it had teeth set in sockets, claws on the ends of its wings (although the hoatzin in South America still does today), and a stronger than usual pelvic bone. However it also had muscle attachments (skeletons can reveal a lot) consistent with strong flying (like a raptor today), feathers, and strong talons.

Archaeopteryx also had a long, bony tail; no large, projecting keel associated with the sternum (& a keel is the place where birds’ big flight muscles are attached); and little fusion of bones in the spine & limb girdles. It didn’t have the horny (keratinised) bill that you see in birds. And that pelvic bone (girdle?) may have been strong but its morphology is like that of dromeosaurs, not birds. The point at which the head attaches to the spine, and the form of the cervical vertebrae, is also reptilian, not avian. Yes, skeletons can reveal a lot, and what this (partial) list shows is that, while Archaeopteryx had a number of features we normally associate with birds – most notably, its feathers – it also possessed a large number of features that link it to reptiles and, more particularly, to theropod dinosaurs. It is, in other words, an example of a transitional form.

As for the strong flight that our website’s authors are arguing for – the relatively flat sternum doesn’t support that. Similarly, modern birds have what are known as uncinate processes on their ribs, which help strengthen the ribcage against the compression stresses generated by flight. Archeopteryx didn’t have those, either…

Modern biology textbooks picture the archaeopteryx as an awkward flier, or even glider, which could run and climb well, as a transitional form between reptiles and birds. This is probably the most famous fossil in the world other than some “ape-men”.

Ooops. I guess they don’t agree with the idea of human evolution either. Anyway, Archeopteryx probably didn’t climb trees on a regular basis: if it did, its wing claws would be worn down – but the fossils’ claws are sharp & unworn. So, when it flew, it would have taken off from the ground.

Firstly, evolution is very short of transitional forms so the most has to be made out of whatever can be found.

Bzzzt! Wrong answer. Look here for a list (by no means complete). The transitional sequence for amphibians is a great exemplar.

Secondly, we know by the muscle attachments and feathers that archaeopteryx was a strong flier, making some pictures in biology texts intentionally deceptive.

See my previous comments. The structure of the primary feathers on Archaeopteryx‘s wing tell us it flew, but the evidence from sternum & ribs suggest that it was not a strong flier – something that Pat Shipman discusses at some length in her book “Taking Wing”. So no intentional deception there – but perhaps a failure to look seriously at the available evidence by our authors.

A true transitional form must have structures that are part way between feathers and scales, and forelimbs that are partway between legs and wings. Everything on the archaeopteryx is fully developed. Like the platypus it is an unusual collection of fully developed traits.

Nice straw man argument there! This is not how biologists describe transitional forms.

Incidentally, modern birds have been found in the same and lower levels than archaeopteryx.

Bzzzt! Wrong again. The early birds contemporaneous to Archaeopteryx were not truly “modern”, although you could argue that they were more bird-like than Archaeopteryx. (I wonder if they may be referring to Protoavis?)

Some mammals have teeth and some don’t. Some fish have teeth and some don’t. We don’t see any issue with a fossil bird having teeth. And again, if fossil birds had teeth and today’s don’t, it is a loss, not a gain of genetic information.

Well, no - because some rather cool experimental work has shown that hens still have the genes controlling tooth development, so there has been no ‘loss’ of information. Sorry, guys, if you are claiming to teach science, then it would be a good idea to actually check out the available information rather than making these unsupported statements. In other words, your concluding statements don’t match the evidence & are wrong, wrong, wrong – and betray a wilful misunderstanding of evolution, as well:

Artists have creatively imagined what a true transitional form between reptiles and birds may have looked like. Such “creatures”, if they ever existed, wouldn’t be able to either fly or climb or run properly to escape predators or catch prey. Natural selection would have removed them. (Natural selection is on our side.) The unwelcome position of the evolutionist is that every step, and every small change, must be useful to the carrier to avoid being selected against.

Sigh. Spot the straw men? Not to mention the misunderstandings about natural selection & how it operates…

Update: the February 2011 National Geographic stated that the archaeopteryx, whose well developed feathers causes [sic] a problem for dino to bird dating, was probably such a good flier, that it could probably take off from the ground [emphasis in the original]. Well done National Geographic! We hope that the corrections flow down to the textbooks, but this may be hoping too much.

What is really hoping too much, I suspect, is that the authors of this school’s site take the time to look carefully at the available evidence & see where that leads them. (National Geographic’s represenation of a land-based takeoff is right in line with what most palaeontologists have said for years.) In this particular case they could make a start with reading Shipman’s book for an introduction to the science that’s written for the lay reader.

Pat Shipman (1988) Taking wing: Archaeopteryx and the evolution of bird flight. Touchstone. ISBN 0-684-81131-6

writing about environmental history Alison Campbell Nov 17

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Over lunch today I had a really interesting conversation about environmental history and why it’s a Good Thing to know about. Much of the discussion was around the environmental history of Palmerston North, where I lived for about 22 years, first as a student at Massey University & subsequently as a teacher (first in various secondary schools before returning to Massey on the other side of the lectern). Palmy can certainly be a soggy place** – but I suspect very few residents know that until relatively recently it was a place of lagoons & wetlands. One such site was the Awapuni lagoon, in the area now occupied by Palmerston North racecourse – I used to walk through there all the time with my previous dog Bella (who used to loooove puddling around in the Mangaone stream). While it’s now simply a low-lying area (prone to pooling quickly in prolonged downpours), in the not-so-distant past the lagoon was a significant food source for the local iwi, who had a small village there.

But this history doesn’t have to be hidden, & in fact you could argue that it’s really important for school students to learn about it. After all, how can you really make sense of your current environment, except in the context of what went before. One person who’s actively telling these stories of our past environment is Dr Catherine Knight, who writes the blog envirohistory NZ (& who sat across the table from me at lunch). She’s created a veritable goldmine of stories about our past, relevant to students of history, geography, social studies… it’s not just biology students who could benefit from it. Pop over & have a look :-)

**I can still remember the flooding that occurred back in 1988, Cyclone Bola hit New Zealand. We were living in Rongopai Street at the time, 2 doors down from the Mangaone. There’d been some dumping of hedge-clippings, by someone who lived further upstream, & when the stream rose rapidly under the constant heavy rain, said clippings blocked the culvert & the water spread rapidly across neighbouring sections. Including ours. We’d actually been out to see friends on the other side of town – OK, I’ll admit it, to see the flooded paddocks (dratted sightseers!) - and when we got home our section was awash & there was water flowing through the garage. The house was all right, being on a high pad, but the rabbit had fled his tunnel under the sunporch & taken refuge in the greenhouse, courtesy of the neighbours who opened the door for him. The veges took a while to recover from that little incursion!

picking & choosing what to believe in… Alison Campbell Nov 13

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In my last post on a ‘creationist biology curriculum’ I asked the question: what, exactly, do they teach? Over on the Sciblogs site (where this blog is syndicated), a commenter answered by pointing me at another school’s curriculum. As I read through it, I could feel the area beneath my collar getting distinctly heated.

This was partly due to the sections listing Commonly accepted science we believe in and Commonly accepted “science” we do not believe in. What we have here is an a priori assumption about the world, followed by rejection of anything that doesn’t match that particular worldview. This is not how good science is done. (And note the use of scare-quotes denoting the science that the authors don’t believe in.) And this makes me wonder just how well their students will understand the overarching strand of the national science curriculum, the nature of science.

It also reflects a fundamental misunderstanding, misinterpretation, &/or misrepresentation of the science. For example, under the list of stuff they choose not to belief, we find this (emphasis in the original):

Neither do we believe that genetic information can increase, or ever has increased, in complexity over time. New genetic information (eg: a random mutation) must be useful to the carrier to eventually be prevalent in the population (natural selection is on the creationist side), and it must add genetic information to support evolution theory. Such mutations are unknown to science. The very small number of known useful mutations, and the best examples in textbooks, all switch off or damage a pre-existing metabolic pathway. They do not add additional, useful information. Also, if the environmental condition which caused the mutation to be useful (eg malaria for sickle-cell anaemia, antibiotics for bacteria) is removed then the mutation is discovered to be harmful and the “useful” mutation is selected against by natural selection.

Now this is just plain wrong! And at best it indicates a lack of knowledge about modern genetics. A mutation that results in the duplication of a gene, for example (the ‘jumping genes’, or transposons, are often involved here) will result (& has resulted) in an increase in ‘genetic information’. The family of human haemoglobin genes is one such example, and if you want historical evidence of duplications then you need go no further than pseudogenes, which litter the mammalian genome and provide very good indicators of phylogenetic relatedness and – dare I say it – evolutionary change. (This paper on the evolution of the haemoglobin genes is behind a paywall, but there’s a good general article on Wikipedia.)

Another example of a well-known gene-duplication mutation is the differences in salivary amylase gene copy-numbers between different human populations. Yes, of course some increases in copy-number can have harmful results – the point here is that contrary to the assertions in the curriculum I’m looking at here, some mutations can and do result in an increase in genetic ‘information’ (copies of genes) that is beneficial to the individuals carrying those mutations. Such mutations are not ‘unknown to science’!

The statement that a mutation must add genetic information to support evolution theory is simply a straw man: all that evolution requires is a change in information that results in a change in phenotype that may be subject to natural selection…

As for the final sentence in that quote, well, the best that can be said is that the author really doesn’t understand the thing they are criticising (or the things they accept, seeing as how they say that natural selection is acceptable). Context is important! Conditions in a given environment may select for particular mutations (in mitochondrial DNA, for example), but the same mutation may well be selected against in another environment. No surprises there, it’s what evolutionary biology predicts. Being heterozygous for the sickle-cell allele conveys a selective advantage in regions where malaria is common – an advantage over both homozygous ‘normal’ individuals (who tend to die of malaria) and people homozygous for sickle-cell (who die from the multiple phenotypic effects of this disease). In a different context ie in the absence of malaria, then the ‘normal’ phenotype will win out. Guys, this is how natural selection operates!

what, exactly, do they teach? Alison Campbell Nov 12

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I was spurred to write this by a comment  Grant made on my previous post on the various NZ political parties’ stances on science education. In that post I linked to the website of a ‘special character’ school: one with a religious underpinning & which states that they replace ‘evolution’ with ‘creation’ in the school’s science curriculum:

All strands are covered as stated in the National Curriculum: The Living World, the Physical World, the Material World and Planet Earth and Beyond. As a Christian school we change the sub-strand called ‘Evolution’ to ‘Creation’. This links with our extra subject Creation Studies.

Which leads me to wonder exactly what such schools do teach in science classes…

Possibly a rather incoherent Living World curriculum, especially given that the National Curriculum document has this to say about the Living World strand (my emphasis):

The Living World strand is about living things and how they interact with each other and the environment. Students develop an understanding of the diversity of life and life processes, of where and how life has evolved, of evolution as the link between life processes and ecology, and of the impact of humans on all forms of life. As a result, they are able to make more informed decisions about significant biological issues.

It’s hard to make sense of many biological processes when the underlying organising principle is removed from discussion…
Since the curriculum mentions a ‘Biblical world view’ then I’ll assume that it teaches the ‘Young Earth’ variety of creationism (I am happy to be corrected on this), including such supposed events as a global flood.  But then, the Living World strand, for young primary school children, offers the following learning objective:
Evolution
• Recognise that there are lots of different living things in the world and that they can be grouped in different ways.
• Explain how we know that some living things from the past are now extinct.
First up there, we have the issue of species diversity: where did all those species come from? Even young children know that there are an awful lot of living things. Was every single one of them specially created? And what about the idea of extinction? I’m thinking particularly of the dinosaurs, so beloved of young children – perhaps because they are (many of them, anyway) big and fierce, & (all of them, ignoring for the moment that birds are essentially small feathered reptiles!) extinct. I have seen it argued that dinosaurs are still alive to day (yes, really!), but doesn’t this generate new questions? How did they all survive the supposed flood, for example?
And that in turn generates another question: how, using a curriculum that posits a geologically young Earth, can you teach children the critical thinking skills they need? After all, even for young primary-age children the National Curriculum “Nature of Science” strand requires (my emphasis again) that they
[l]earn about science as a knowledge system: the features of scientific knowledge and the processes by which it is developed; and learn about the ways in which the work of scientists interacts with society.
And careful, critical thought lies at the heart of scientific knowledge.
But it’s not really just the Living World & the ‘E’ word, is it? Because in order to deny evolution, you must also deny quite a lot of geology (Planet Earth & Beyond) & physics (Physical World) as well. James Hutton & Charles Lyell, for example, used the (glacial) speed and relative constancy of observable geological processes to infer that the Earth is very old, & this is borne out by the physics of radioactive decay that underlies radiometric dating techniques. (In an example of special pleading it’s been argued that rates of radioactive decay were faster in the past, thus giving the appearance of a young Earth, but alas! were that really so, then the Earth would also be a ball of molten rock, due to the large amount of heat released by the accelerated rates of decay…)
Yes, OK, I’ve jumped to the senior years at school here (you’re not going to learn about radiometric dating at primary school!), but my point remains: how can such a curriculum truly help children to understand and make sense of all that the world offers? (Let alone prepare those who go on to study biology – and geology – in a university system where evolution lies at the heart of our understanding of the living world.)

Election time: Science Q&A – education Alison Campbell Nov 08

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The Science Media Centre has just released its ‘Science Q&A’ – a set of questions put to all main political parties. As a voter I’m interested in all the responses, but today I’ll wear my science educator’s hat & look at the responses to this question:

Not only does New Zealand have problems persuading young people to study science at university, it has difficulty persuading graduate researchers to eventually settle in this country. How will your party make science and technology more attractive to students looking ahead to tertiary education, and what can be done to encourage them to work in New Zealand?

I’ll look specifically at the education bit, as that’s really where I sit & anyway, I’m sure that research scientists will have plenty to say on the ‘encouraging students to work in NZ’ front. (For those not familiar with my background, I’m a science educator/communicator first & foremost, & that’s where my research interests lie as well.) Responses are in alphabetical order, so that means we get to read the ACT party’s thoughts first. The party feels that

To the extent that primary and secondary schools are failing to attract students into science, it is a failure of the entire system affecting almost every student. We believe it more likely that more science friendly schools, teachers and curricula will evolve in a more decentralised system.

This leads me to wonder if the party’s spokesperson has actually looked at the NZ science curriculum… and about their attitude towards a nationally agreed standards (& no, I don’t mean ‘National Standards’).

That is, a system where the funding follows the child and teachers and principals have more autonomy about how they run their schools. For example, in the Canadian province in Alberta where anybody can set up a special character or charter school there are now thirteen such schools including the Calgary Science School which takes a scientific approach to learning.

One wonders why they didn’t also cite the decentralised system of the US, where science teaching is distinctly uneven in quality & where scientists and science teachers are constantly fighting efforts to have creationism taught in the science classroom. (Actually, come to think of it, we already have ‘special character’ schools that do just that.) This is not a good model for New Zealand education. I’m afraid I would have to give ACT a ‘not achieved’ for this item of assessment.

Next, the Greens:

[We] need to support secondary school teachers to inspire the next generation of scientists among us. Research shows that enthusiastic teachers do make a difference. Teachers need to have the time and energy to be creative in pupil-focused activity rather than burdened with administrative demands. To address this we support initiatives like after six years of service, teachers, including early childhood education teachers, will be entitled to a sabbatical leave for one year at 80% of their salary.

As an ex-(very ex-) secondary school teacher, & someone who works a lot with current secondary teachers, I can certainly emphathise with this one. One of the big issues for teachers is the need to keep current in terms of subject knowledge – hard to do when your hands are full with the demands of teaching, pastoral care, administration (including the ever-present assessment) & planning for next year or next term. In addition, the amount of money available to fund professional development is very small; just getting funding to go to the 2-yearly subject teachers’ conferences can be difficult. My experiences with teachers who’ve been lucky enough to get Royal Society teacher fellowships showed me the huge difference in drive, energy, & general enthusiasm made by a year out of the classroom, working with scientists and thinking about how to translate what they were doing back into the classroom. These teachers were returning to the classroom able to help their students learn about real, current science, & often to involve them in doing that science – how better to enthuse those kids? The downside, of course, is cost… The benefits to teachers & students would be signficant – but so would the costs of ensuring sufficient staff to cover such sabbatical leave (even at 80% of salary). So the actual budget for this would bear careful examination.

From Labour:

The years immediately following graduation are critical to consolidate the careers of scientists. With the removal of post-doctoral scholarships in 2010, New Zealand is at risk of losing hundreds of our best brains overseas. Labour will reinstate post-doctoral fellowships for recent PhD graduates, scaling up to a cost of $6 million a year, so they are supported into research careers in New Zealand instead of overseas. Labour will also establish a scheme for better funding [for] brilliant scientists. This funding will be portable to allow scientists to take it to the most appropriate institution, purchase equipment, recruit staff and attract other world leaders in the field to NZ. Labours full science and innovation policy, with more details on science in education, will be released shortly.

So not much there on the wider area of education, apart from the comments on post-doc scholarships – what I’d like to know is their take on encouraging our young students to study science in the first place. (Reinstatement of scholarships for top doctoral students would be good too…) And their support for science teachers in schools, and for education in general. Overall, a disappointing answer. (And, just to state any possible conflicts of interest – I’m normally a Labour voter.)

And National:

The attraction of science and technology for young people is directly linked to how it fits in with how they see their futures. The more important high technology industries are to our economy, the more people will want to work in the sector. Greater opportunities will lead to greater interest.

Not necessarily… Science & high-tech industries are important to our economy now (I mean, the idea’s not new; Sir Paul Callaghan has been pointing this out for some considerable time) & yet we don’t see students flooding into the sciences. And across the ditch, back in 2006 The Australian was pointing out that there was a serious shortfall in geology graduates, compared to the demand from industry. The Australian noted (my emphasis) that:

Geoscience is fundamentally important to Australia’s future in three ways. First, geological resources drive a large percentage of the nation’s economy. Second, sustainable development, encompassing environmental protection, depends heavily on geoscience. Third, geoscientists produce most of the data required to understand climate change.

And yet at the same time the number of students taking relevant subjects was in decline & geology departments around the country were closing. It would appear that economic significance is insufficient to drive student demand.

More from National:

We‘re developing five new vocational pathways for young people through a partnership between industry training organisations and the education sector. They will clarify the existing array of options so students and their families can see the connection between what students learn at school and what industries it could lead them to.

Now this, I see the sense in. Many year 13 students don’t go on to university study (& of those who do, probably most don’t go into the sciences.) We’re not particularly good at promoting alternatives – or at providing good subject advice for those students who have other career pathways in mind. I mean, a student might think that ‘getting into’ a manufacturing industry (or the hospitality industry, or…) is a good future, but back in year 11, what sort of program planning is available? Because that’s when they should be doing their subject planning, & the subjects need to be relevant. So the statement that

[M]anufacturing and technology is one of those pathways. The vocational pathways will describe the learning, and the assessment standards valued by broad sectors of industry. They will also include a career and study map, which will show young people potential occupations and future study options

is a good one. Of course, schools – and industries – are going to need support in setting this up, so again the devil will be well & truly in the detail. And of course we still need people doing the basic science and engineering research that will underpin these industries of the future, so those educational pathways also need reinforcement – we need more of those uni-bound year 13 students going into the sciences, not fewer, & that sort of change needs to begin much earlier in the schooling system. So far, neither major party’s said much about that…

you could probably sell anything with the right sales pitch Alison Campbell Nov 06

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My post about zeolite & the supposedly ‘chemical-free’ nature of various dietary supplements containing the stuff led to some interesting comments, & generated a few ‘I wonder if…’ moments. After all, as Krebiozen said (in the comments thread to that post):  With the right sales pitch you could probably persuade some people that eating feline ‘tootsie rolls’ is good for them. They are 100% natural after all!

And goodness knows, if people will eat kitty litter itself (some brands are basically just zeolite) for its supposed health benefits **, he might just have a point. After all, how much of a step is it from coffee beans that have been through the gut of a civet to some of the other organic (see, that’s a Good word) materials emanating from the back end of a feline? As Herr Doktor said, there’s probably quite a bit of nutrients there, given that cats (being carnivores) have a relatively short gut & a reasonably rapid transit time (you will find perhaps more than you wanted to know about cats, their guts, & the products of said guts here): once ingested, food may reach the large intestine within 8 hours, although it may take well over a day to move on out from that point. (This was determined by giving cats capsules containing radioactive markers – after first emptying the colon using a series of enemas. Cats have an alarming array of sharp pointy bits – I would not care to try administering one enema, let along a series of them!)

Of course, much of the mass of faeces is actually bacteria: around 50%, in humans. So you’d want to scrub them out of the ‘tootsie rolls’, somehow. At first I thought you’d also need to remove the eggs from tapeworms and roundworms that would also be present in cat poo. But on second thoughts – why would you? After all, in newspapers from the early 1900s, you could find ads for diet pills containing tapeworm eggs (& there’s various urban myths around that may be based on this). And I was gobsmacked to find at least one website offering ‘diet pills’ that supposedly contain these eggs. (Whether they do or not is open to question.)

As for the roundworms… Well, any infection with a significant number of roundworms is going to leave you feeling rather the worse for wear. But an intriguing study from the University of Singapore suggests that a protein produced by a species of roundworm may possibly reduce the strength of allergic reactions. The impetus for this study was the observation that there seem to be fewer allergies in populations with a high burden of roundworms, something that’s also discussed in Robb Dunn’s entertaining book The Wild Life of Our Bodies: predators, parasites and partners that shape who we are today (2011, Harper Collins).

So, there’s our marketing ploy: all-natural, organic (& therefore ‘chemical-free’), & not only an excellent nutrient supplement but also a slimming aid & something that ‘supports your immune system.’ What’s not to like?

Except… if I can think of it, you can pretty much guarantee that somewhere, someone else will have beaten me to it. (As, indeed, the ads for tapeworm-egg diet pills demonstrate.) And also, imagination is one thing, & humour is good, but if you consider yourself a good, ethical person – & I do – then you’ll never go any further down that road.

** As Herr Doktor Bimler found out (see his first comment), at least one site selling ‘liquid zeolite’ promotes it as a means of removing teh ebil aluminium from your body. One suspects the person or persons making this claim are not chemists – for zeolite is an alumino-silicate mineral, & consuming the stuff is more likely to add to your overall aluminium load than it is to reduce it! (I would prefer to think that the sellers are ignorant of chemistry, as the alternative is that they know damn well what it is & don’t particularly care.)

visualising a curriculum Alison Campbell Nov 04

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I’m always looking around for ways to improve my teaching, & my students’ learning. (The two go hand in hand. I might think I’m a good teacher, but unless my classroom practices improve my students’ learning experiences & outcomes, then I’m not. Not really.) Part of my search involves quite a bit of reading from the science education literature, and recently I read something that gave me a bit of a wake-up call. As Brydget (who runs our first-year labs) said, “it seems so obvious when you think about it!”, but neither of us had actually thought from that particular viewpoint before?

So what was the idea that made us that little bit uncomfortable, & shifted our thoughts on communicating science in the classroom? (That discomfort, incidentally, is a Good Thing, & something we should seek to elicit in our students every now & then.) It’s contained in my current ‘light reading’: a book by Linda Nilson (2007) called The Graphic Syllabus and the Outcomes Map.

I bought the book because I’d been wondering for a while how better to communicate with my first-years about my papers: what they’ll be doing, when they’ll be doing it, that sort of thing. There’s always been a proportion of the class who fairly obviously don’t bother reading the ‘standard’ paper outline (they’re the ones who are startled to find out that yes, there’s a test tomorrow night! even though that information is there in black-&-white in the paper outline that they received on the first day of semester. That, plus the fact that I use concept maps a fair bit in my teaching anyway, made Nilson’s book catch my eye.

We use paper outlines (syllabi – or should that be syllabuses??) to communicate (we think!) a lot of information to our students. Of course there’s the list of topics to be taught & when they’ll be taught, plus a list of student learning outcomes. (The latter are intended to allow the students to judge their progress towards the paper’s goals.) But then we include a whole pile of administrative stuff, like required textbooks, due dates for items of assessment, what constitutes plagiarism & why they should avoid doing it… And we expect them to read all of it.

Nilson suggests there are good reasons why many students don’t or, if they do, why they don’t seem to process the information particularly well. Part of the problem may be that the syllabus is all text – she cites research indicating that [only] half of 18- to 24-year-olds in the United States read a book of any kind in 2002, and only 22% of 17-year-olds read daily in 2004. And worse – for many of those who do read the document, it may not actually make much sense to them.

This is the point where Brydget & I had that ‘aha’ moment. When a lecturer puts together a paper outline, they do it from the perspective of someone who’s totally mastered the content and the language involved. But for students, especially first-year students who are ‘content novices’, it’s a different story:

Even if students do read the syllabus, the content-heavy sections might not make much sense to them. Certainly one of the most content-laden sections is the schedule of topics that the course addresses. The topics usually contain technical terms of the discipline, terms with which the students are initially not familiar. if they already knew these terms, they wouldn’t be in the course to learn about them. Not surprisingly, the topics in syllabi in the sciences, mathematics, and engineering are almost exclusively technical worlds that a typical student wouldn’t understand until well into the course.

This is actually a deeper issue than a simple failure to read all that ‘stuff’ at the start fo the study guide, or in the first handout of the semester. It may also mean that the students don’t get any real idea of how the course is organised. You might think, “what does this matter? They’ll have it sussed by the end of the semester.” But there’s more to it than that. When we learn new things, if we’re to learn them in any meaningful way we need to be able to fit them into some sort of mental scaffolding, or schema. As Nilson says,

learning and storage take place only in the context of a logically organised conceptual framework. Deep processing, as opposed to simple memorisation, necessitates seeing the structure of new knowledge and integrating it into one’s existing structure of prior knowledge.

What’s more,

Our thinking is so dependent on structure that if we don’t have an established, complete logical structure to interpret and explain an observed phenomenon, we will make up connecting pieces or entire theories.

So there’s a real risk that many students won’t actually be learning what we think they’re learning, however well-structured our classroom teaching practices may be. So how can we help them understand the organisation of a course, so that they can use that to help incorporate the things they’ll be learning into their existing body of knowledge? nelson suggests the use of ‘visual’ syllabi that present course structure in flow charts or concept maps, showing what they’ll be learning (both content & process knowledge), how it all fits together, and how it links to material they might have already learned and to future courses.

I’ve used concept maps in class for years now, but while I know how well they help students to come to a deep understanding of complex information, I’d honestly never thought of using them to visualise the organisation of an entire paper. So that’s my next little project – to develop such a visual syllabus for the first-year biology papers I coordinate. And, at the end of the semester, I’ll be asking students for some feedback, so that I can gauge how useful that schema might have been to their own learning.

After all, my own learning journey is nowhere near its end :-)

Linda B. Nilson (2007) The Graphic Syllabus and the Outcomes Map. pub. Jossey-Bass. ISBN978-0-470-18085-3

deconstructing zeolite Alison Campbell Nov 02

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Years ago, when my old dog Bella was still alive, I was the happy recipient of several doggy haiku verses. One of them read:

The cat is not all bad./She fills the litter box/with tootsie rolls.

I was reminded of this when reading the comments thread on a recent post by Orac. Some commenters were discussing claims that the mineral zeolite has enormous healing powers and other health benefits. Going by the amount of the stuff that Bella would have ingested along with the aforementioned ‘tootsie rolls’, perhaps it’s no surprise that she reached the advanced (for a labrador) age of 15…

However, the comments left me with alarming mental images of people also chomping through kitty litter, albeit in a finely-ground form and without the organic inclusions that so delighted Bella (& which also delight young Ben-the-poodle). You can certainly find the stuff widely promoted on-line (at naturalnews.com, for a start). And yes (alas!) there are purveyors in New Zealand as well, although the outfit that came up tops on a google search sells it in liquid form.

I really should send them a bill for a new irony meter. For on reading the promotional blurb, one is told that It is chemical free: LIQUID ZEOLITEâ„¢ is processed without chemicals. This, on the same page that proudly proclaims the actual materials in this wonderful product:

humic acid/fulvic acid complex, ultra-cleansed volcanic zeolite (clinoptilolite) and a blend of angstrom-sized trace minerals, phyto-nutrients, macro-nutrients & micro-nutrients,DHQ (Dihydroquercetin), “M-Water”, citric acid, Preservative: potassium sorbate.

You can see why the meter went kablooie :-)

Humic & fulvic acids are produced by the breakdown of dead organic matter, & are widely used in agriculture as soil supplements. Since to the sellers of ‘natural’ health products the word ‘chemicals’ is used for teh ebil ‘artificial’ substances, I suppose I can see why they would classify these acids as ‘non-chemical.’ Clinoptilolite is the technical name for zeolite, & from the seller’s blurb the ‘ultra-cleansing’ has been done by treating it with concentrated humic acid. So that’s all nice & natural too.

I’m intrigued by the idea that the product contains ‘angstrom-sized trace minerals’, since angstroms are definitely on the nano-scale and people do have concerns about the health implications of products containing nanoparticles (not an issue I want to address here). Goodness knows what the ‘phyto-nutrients’ et al. are, so it’s not possible to check how they are extracted – in commercial quantities – from the source plants…

DHQ is apparently one of the most potent [antioxidants] in the whole world, or so this site tells us, & it has all sorts of claimed health benefits. (With a name like dihydroquercetin, I thought, it sounds like something you’d get from oak trees – turns out that it’s extracted from larches.) I’m always a bit puzzled about the promotion of antioxidants – the process of oxidative phosphorylation is key to production of energy in our mitochondria, & that’s definitely not something I’d want to stop! Extraction of DHQ, however, definitely involves those nasty chemicals, in the form of organic solvents. Do the liquid zeolite folks know?

“M-water” – this is pure comedy gold in its own right. Honestly. I couldn’t make this stuff up if I tried, which I suppose suggests a certain failure of the imagination. Apparently M-water is much better at hydrating your cells than the stuff that comes out of the tap & – as one of Orac’s regulars remarked – is obviously much better than the nasty dehydrated water that you get when the tap’s turned off. He was right on the button, if the M-water sellers are to be believed: apparently most other functional water products will actually cause dehydration instead of improving hydration. As I said, you couldn’t make this stuff up.

Citric acid – well, I suppose someone could be squeezing a lot of lemons for this product, & since lemons are natural then they must also be chemical-free. But potassium sorbate? It’s obtained by neutralizing potassium hydroxide with sorbic acid, an unsaturated carboxylic acid that occurs naturally in some berries. Yup, they definitely owe me for a new meter!

And that’s even without going into the various health benefits claimed for consuming zeolite in its various forms. One of which is that it chelates various ‘toxins’ including mercury. A search of pubmed using ‘zeolite chelation’ as the search term produces just 2 references, neither of which looked at zeolite in a human-health context. ‘Nuff said.

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