SciBlogs

Archive June 2012

what constitutes beauty? – tarantulas! Alison Campbell Jun 26

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Wellington Zoo has just imported 106 Chilean rose tarantulas as part of a captive breeding program for these lovely animals. From the tone of a letter in today’s Waikato Times, the spiders are also in need of a public relations officer.

For in today’s Waikato Times, we find the following letter:

I could hardly believe my eyes when I read that Wellington Zoo had just imported 106 venomous tarantulas from Wales.

OK, I thought, someone who’s understandably not too keen on potentially dangerous exotic animals coming in (although the tarantulas don’t pose any real risk to our biodiversity, given that the zoos will need to keep them in heated terrariums: they would not be able to survive long in the wild). But I was wrong. The writer continues

Collections development manager Simon Eyre said: “We’re excited that visitors will be able to see them close up and gain a real appreciation for their beauty.”

Am I missing something? A lamb or deer is beautiful – but a cruel, carnivorous tarantula?

Well, I guess beauty is in the eye of the beholder**, but what’s this cruelty stuff? Tarantulas do what tarantulas do, and nature is indeed ‘red in tooth and claw’ at times. That’s nature for you. But the overlay of cruelty is a human-perspective construct.

Given that these spiders can live for more than 20 years, how many defenceless crickets, grasshoppers, etc will be subjected to a cruel and terrifying death when dropped into the tank with these monsters who “use their venom to liquefy the insides of insects”?

At 4-6 crickets every 3 weeks (or a locust a week), the answer is about 2700/tarantula, over those 20 years. The intake would be pretty much the same, whether the tarantulas were in the wild or in captivity. The scare quotes really aren’t needed for the spiders’ feeding method, though; again, it’s just the way spiders – all spiders – feed. They’re an example of fluid feeders, sucking up pre-digested food once the enzymes in their venom have broken down the dead prey animal’s tissues.

In the wild, prey would at least have a chance to save themselves. In this day and age, when we can learn everything about animals from documentaries and the internet, there is no justification for imprisoning any animals in zoos. Importing venomous spiders seems like madness as well.

I have to disagree – we can’t “learn everything” from sitting in front of a monitor. We can be awed & amazed & horrified, perhaps, but I do think that the world would be a sadder place if people never had the opportunity to actually see a living, breathing meerkat, or tiger – or tarantula. A well-designed zoo is as little like a ‘prison’ as possible, and in a world where the natural environment is under threat from human activity, for many species a zoo may be a place of refuge. (Pere David’s deer would have long since become extinct without one.) Those animals on the other side of the glass, or fence, or moat are ambassadors for that endangered environment in the way that a ‘virtual’ creature can never be.

 

** and if you want a beautiful little spider, how could you possibly go pass the lovely peacock spider? This gorgeous little salticid has the usual jumping spider cuteness and complex courtship dance, all set off by colours I’ve never seen before in a spider.

another silly homeopathic product Alison Campbell Jun 22

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Checking my in-box today I came upon this offering:

HCG Diet Direct – hCG Diet Drops – Homeopathic Drops

HCG Diet Direct – Lose weight on the homeopathic HCG Diet without heavy exercise or without frozen or prepared foods to buy. HCG Diet Direct – a brand you can trust

http://losskilosmore.ru

HCG = Human Chorionic Gonadotropin, a hormone produced during pregnancy. Quite how it would help you lose weight, I am not sure. The idea that it could do so appears to be based on claims that – in combination with an ultra-low calorie diet (around 500 cal/day) – use of this hormone would help obese individuals lose weight. However, there is no clinical evidence to support this claim, & I see that in the US over-the-counter sales of ‘homeopathic’ HCG diet products were banned by the Food & Drugs Administration - something our advertiser gets around by being based in Russia. (Although I see you can also buy the stuff here in NZ.)

I suppose you could argue that since the highly diluted nature of most homeopathic products means that they contain no active ingredients, then all you are ingesting is water or sugar pills (the latter, of course, are not going to help with weight loss!), so the product’s hardly going to do any harm. It’s not unknown for homeopathic ‘remedies’ to actually contain physiologically-active levels of various drugs & other chemicals (think Zicam), and this may have influenced the FDA’s ban, but more likely they were working from the viewpoint that there is no way such a weight-loss product could do what is claimed for it. Low-cal diets – yes, the weight should come off (although whether it will stay off is another matter). After all, the original claims about HCG’s efficacy in weight loss saw it combined with that very low caloric intake. So why bother with the additional water/sugar pills? Anyone buying such products in the expectation that the kilos will melt away without any additional effort on their part is likely to be sadly disappointed.

In other news: the Quackometer examines claims that homeopathic products are useful in dealing with sports injuries (worth knowing, I guess, as Olympics fever strikes).

reflections on the WEB days Alison Campbell Jun 13

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We’ve just held the second day of the annual “Waikato Experience of Biology” (WEB) days – around 700 year 13 biology students, & their teachers, have come on campus over those 2 days for a program of seminars + some lab experience that supports their learning in several areas of their Biology curriculum. (There are photos on the Faculty’s Facebook page.) I give seminars on human evolution & other colleagues talk about gene expression, patterns of evolution, biotechnology, and plant responses/animal behaviour.

The students were great – it’s always fun to spend time talking with young people about biology :-) They were also a credit to their schools – when you’ve got a lecture theatre full of 400 year 13 students, & absolutely no issues with noise or chatter during a talk, then that speaks volumes.

I spoke with a lot of the attending teachers as well, just catching up & making sure that we had things pitched at the right level & were meeting their needs & those of their students. (It sounded like we had things pretty much spot-on.) But we also talked about the impending implementation of the new  (‘aligned’) Achievement Standards at Level 3 – this is the last year that gene expression will be taught & examined at that level, for example, as it’s moving down to year 12 & in its place comes a new AS on homeostasis, and another on ‘human manipulation of genetic transfer’ which seems a more tightly focused version of the previous standard on biotechnology.

And it became quite clear that many of those I spoke with were concerned at how well they were going to be able to deliver this new content & develop their students’ understanding of it. One of the things we’ll be doing here at Waikato to support them is running a teacher evening to provide ideas, content knowledge & maybe other resources. If you’re a scientist with an interest in, say, homeostasis (or cloning, or transgenes), and an interest in communicating the science around it, why not contact the HoD Biology at your local secondary school and offer to help? It could be the start of a wonderful new working relationship :-)

a good old debunking – flatulent dinosaurs & aquatic apes Alison Campbell Jun 12

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I took a little time over lunch to catch up with the work of various science communicators, most notably that of Brian Switek, whose blog Laelaps is carried by the Wired website & who also writes Dinosaur Tracking on Smithsonian.com. I’m now regretting my long absence, for not only is Brian an excellent communicator of science, he’s also jolly good at debunking pseudoscience. And I thought I’d share a couple of examples.

The first is his take on a story that caught my eye when it first came out, but I didn’t have the time to something on it myself. That story was was the target of some rather sensationalist reporting that included (courtesy of the Daily Mail, no less) the claim that  that researchers had found that the sheer number & volume of dinosaur farts were sufficient to change the global environment and drive the mega-farters to collective extinction.

Brian points out that this isn’t what the original paper actually said: rather, (in Brian’s words)

[t]he researchers conclude that so much dinosaur flatulence – in addition to greenhouse gases from fires and other sources – might have created and sustained the relatively warm world of the dinosaurs.

And really nice to see a good, skeptical take on the media fuss from TV3′s website :-)

Brian’s other piece caught my eye as I’m currently getting ready for my talks on human evolution at the Waikato Experience of Biology days we run for year 13 bio students & their teachers. Why? – because his debunking of an item about mermaids on Animal Planet mentions the ‘aquatic ape hypothesis’, something that is sometimes mentioned by WEB-day attendees (in much the same way that the ‘Neandertal predation “theory”‘ came up at a session I did in Auckland a couple of years back).

The program’s called “Mermaids: the body found“, & the on-line press release, while it sounds all gushingly science-y, is actually describing a fictional story. (As Brian points out, it even tells you so – in a couple of lines of type at the top of the page, whose sense is then overwhelmed & lost in what follows.)

And what follows includes reference to the ‘aquatic ape hypothesis’ (I refuse to call it a theory) popularised by Elaine Morgan & still doing the rounds (there’s a good backgrounder/overview here). It has surprising longevity for something that has no real evidence to support it: no fossils, for example; and its suggestion that our lack of body hair can be ascribed to an aquatic phase in our history, in the same way that whales are hairless, doesn’t really stack up (otters, seals, & polar bears  - all with aquatic lifestyles – are all remarkably hirsute). And as palaeoanthropologist John Hawks says

[i]t makes sense that hominids would develop new anatomies to adapt to such an alien environment. But once those hominids returned to land, forsaking their aquatic homeland, the same features that were adaptive in the water would now be maladaptive on land. What would prevent those hominids from reverting to the features of their land-based ancestors, as well as nearly every other medium-sized land mammal? More than simply phylogenetic inertia is required to explain this, since the very reasons that the aquatic ape theory rejects the savanna [sic] model would apply to the descendants of the aquatic apes when they moved to the savanna.

In the conclusion to his article, Brian comments that

[s]peculative biology can be a lot of fun – to wonder how different forms of life might have evolved. And, with the right context and presentation, Mermaids could have been a unique way to highlight evolutionary and biological ideas.

A pity that this seems to be an opportunity that missed its mark.

the great class-size debate Alison Campbell Jun 11

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I haven’t blogged much lately, due to a combination of factors to do with my ‘day’ job. But I’ve followed the recent heated debate around proposed changes to class size with much interest, & I did manage to pull together something for my ‘other’ blog. So I’ve reproduced that here :-)

Here in New Zealand, the compulsory education sector has recently received a lot of media & political attention (see herehere, for example), culminating in the reversal of a Ministerial decision to change pupil-teacher ratios in our compulsory schooling sector. Part of the money ‘saved’ by this move was to have gone towards improving teacher quality, a praiseworthy goal but one that so far lacks any clear mechanisms to support it (apart from a Ministry of Education statement that ’[r]aising the quality of teaching will be helped by attracting higher quality applicants, raising the entry criteria for becoming a teacher and improving the quality of programmes of learning in ITE [Initial Teacher Education].’

Like most educators I know, I was concerned at the now-reversed proposal, for a number of reasons.

First up: the cuts in teacher numbers would have impacted hardest on intermediate schools with technology units — units offering technology classes both to their own students & in many cases to students from smaller ‘client’ schools. These classes give students the opportunity for a range of hands-on experiences — including science-based experiences — that they’d otherwise miss out on. At a time when primary schools have been reproached because many pupils miss out on quality learning in science, it did seem strange to put intermediate schools into a similar position by incorporating technology staffing for students in years 7 & 8 (the ‘intermediate’ years in NZ) into the curriculum staffing rations for years 2-10, with the end result that some schools stood to lose several teachers in this important learning area.

Secondly, part of the rationale for raising pupil-teacher ratios at all — and I recognise that for many schools there would probably have been little change — seems to have been the idea that class size doesn’t matter; that ‘teacher quality’ (however it’s defined) is more important. However, it’s clear from meta-analyses carried out by Prof John Hattie (then at the University of Auckland) that smaller classes do see appreciable changes in ’[a]chievement, attitude, teacher morale and student satisfaction’ — in classes of 10-15 students (a rarity in most schools at most levels), with little effect when class sizes change from around 40 to 20. This was the case across all subjects & levels of student ability, in both primary & secondary schools. And it’s likely that one of the key factors involved in these improvements is time: the fact that in smaller classes teachers have the opportunity to spend more time with each individual student, providing feedback & reinforcement on a one-to-one basis.

For Hattie has found that

the most powerful single moderator that enhances achievement is feedback. The simplest prescription for improving education must be ’dollops of feedback’ – providing information how and why the child understands and misunderstands, and what directions the student must take to improve

where ‘feedback’ includes things like ’reinforcement, corrective feedback, remediation and feedback, diagnosis feedback, and mastery learning’ (based on that feedback). And giving that sort of feedback takes time, & quite a lot of it.

Funnily enough, just about every year when the paper & teacher appraisal results for my papers come in, my lowest score is for the statement ’this teacher regularly provides me with feedback about my progress’. Now, I suppose you could say that in a class of ~200**, the opportunities for me to provide this are limited, but in fact students get feedback in class via things like pop quizzes; on Moodle — for example, through ‘common errors’ feedback almost as soon as essays are submitted; in writing, on test papers & written assignments; & face-to-face. Last year I asked the class about this — it turned out, to my surprise, that most of this was not recognised as ‘feedback’: many of them saw only verbal, face-to-face responses as feedback! This was a timely reminder that teachers and their students don’t necessarily have a common understanding around common classroom terminology.

And thirdly — well, the proposed changes did rather seem to be putting the cart before the horse, in that we seemed to be lacking a common, public, understanding on just what constitutes teacher quality, let alone how we should measure it. (For our national Tertiary Teaching Excellence Awards, the latter is done on the basis of portfolios submitted by those nominated for an award: a daunting task where there are some dozens of portfolios. I can’t imagine doing anyone the same for the 52000+ teachers in our compulsory education sector!) Despite all the heat around issues such as class sizes & performance pay, what we haven’t had is just that public discussion around what constitutes an excellent, expert teacher. There are studies (again, including work by John Hattie) that identify the attributes of such teachers. What we seem to lack is any agreement on how to apply these studies to the classroom in order to identify & esteem those experts — or any substantive discussion*** on how to encourage and support our very many other experienced teachers**** to join their ranks.

**The NZ Herald has covered the whole story in some depth. One of the silliest comments I’ve seen was in response to an op-ed piece by Dita di Boni, when F Max remarked that

And amazingly kids can go from a class of 30ish to a university lecture of 300+ learning far more difficult concepts. So why is the teacher ratio argument ignored at uni? Apparently our universities are in crisis and everyone must be failing. Or maybe it’s less about numbers and more about quality, something most of our teachers greatly lack.

Apart from impugning the professionalism of our classroom teachers, & ignoring the fact that the students in university classes are different in many ways from those in a primary or secondary classroom, F Max seems unaware that uni lecturers like me don’t just stand up in front of a class & lecture at them. Tutorial classes of 10-30 students give much better opportunities for feedback & one-on-one instruction — opportunities that many classroom teachers may only dream of.

*** Perhaps this is something that individual Ako Aotearoa Academy members might be interested in contributing to?

**** And yes – before anyone jumps on me – I’m aware that we have teachers, just as we have other professionals, who are not at the top of their game.

another stunning biological image Alison Campbell Jun 11

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(And once again, I found this via PZ Myers.)

Although it looks like a flower , this is an image of a limpet embryo, stained to show 4 different proteins and viewed (& photographed) using a confocal microscope. There are several other stunning images at the Node, which is an on-line community site for developmental biologists – and you can vote on which one should grace the next cover of the journal Development.

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