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do you mind? (brain, meet brian) Alison Campbell Jul 08

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Today Marcus Wilson & Kathrin Otrel-Cass hosted Science in the Public, a symposium for people involved in communicating with the public through a range of initiatives (including Cafe Scientifique aka Science in the pub). And there’s what looks like being a most promising Cafe event tonight, with Shaun Hendy leading a session on nanotechnology. Anyway, one of the presentations really caught my imagination, & I thought I’d talk about it here.

Megan Dowie is a Research Fellow at the University of Auckland’s Centre for Brain Research . Almost by accident, she found herself the co-curator of an exhibition that presents artworks inspired by the research of CBR scientists. Megan is a really engaging presenter & she quickly drew us all into the story of this collaborative exhibition.

The brain is the seat of movement, memory, cognition, identity, dreams. And we don’t know a lot about how it operates, although staff at CBR (among others) are constantly expanding the boundaries of our knowledge. There’s also the question of how to raise awareness of this research in the wider community. At the launch of the Centre for Brain Research, in November last year, Megan bumped into Leah Forsyth, who with her sister Erin runs The Busy Nice creative agency. They got talking, & the idea of an art exhibition inspired by science bubbled to the surface. This serendipitous event led to the Do You Mind? exhibition. (I quite like this example of serendipity – it reflects the way in which scientists too can make fortuitous discoveries while doing or looking for something quite unrelated to the eventual outcome.)

Over subsequent meetings they put together the proposal that became Do You Mind? Approaches to scientists & artists generated sufficient interest for them to put together 15 scientist/artist pairings. The original introductions were made over pizza & beer at an off-campus location – far more relaxed than coming in to the lab. The scientists showed their artist collaborators around their labs, demonstrated what they were doing, in some cases gave the artists hands-on experience of what was being done. (Megan showed images of brains & brain cells that some of the researchers had generated as part of their work – these images are in themselves beautiful & it was hard to imagine what the artists might do with them.) Then the artists had 8 weeks to deliver an artwork that gave form to the ideas & concepts they’d heard & seen.

In the end there will be almost 40 artworks in the exhibition – this must surely show the inspirational nature of this partnership between art & science. (Megan showed us some & they are lovely.) And this will hopefully generate wider community interest in the research that’s been highlighted through art. But there are greater benefits here too. I’d hazard a guess that both groups recognised that those who specialise in a particular field are ordinary people doing not-so-ordinary things :-) In their feedback, the participating researchers indicated that while they’d learned about art, they’d also learned about new ways of communicating about their science. The artists gained an enhanced appreciation of just what scientists actually do. One artist’s comment seemed to sum up science quite well: the innumerable task of generating problems to solve tomorrow. Do You Mind? strikes me as a powerful example of thinking outside the square when it comes to science communication – doesn’t always need to involve the written or spoken word, & is likely to draw in a wider, or a different, sector of the community.

Oh, and Brian? Who hasn’t typed ‘brian’ when intending to get ‘brain’? But as Megan says, the original mistype gave the project a ‘casual’ name that also personified it (and it was quicker to say!)

PS Yikes!!! I forgot to add the most important bit – the dates & venue!!! Do You Mind? will run at the ‘Irongate‘ “Ironbank” (on K Road). from its launch It’s launched on 28th July & will be open to the public from July 29th until (if I remember correctly) August 7th (yay! I remembered that part OK!).

why an evolutionary image merits a ‘fail’ Alison Campbell Jun 29

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ResearchBlogging.org

 

 

 

Last year I commented that the following image, while funny, was a ‘fail’ in scientific terms:

evolution of the cat.jpg

A recent commenter asked, so is this image scientifically correct or incorrect? (My first thought was that teh lolcat at the end should be a clue…) 

But no, it’s not scientifically correct (lolcats aside). It’s another in the long line of images of ‘evolutionary iconography’ that portray evolution as an inexorable march towards some sort of progress – a generalisation that isn’t particularly helpful in explaining how evolution actually works.

It’s not good on the particulars of feline evolution, either…

The word ‘cats’, in its broadest sense, encompasses 38 different living species, which fall into 8 major groups comprising 11 genera (Johnson et al., 2006). All the extant species have evolved relatively recently: a combination of fossils & DNA analyses suggest their radiation began no more than 11 million years ago (mya) in the late Miocene (ibid.). The earliest divergence (10.8 mya) was between the lineage leading to the ’big cats’ (lion, tiger, leopard, jaguar, snow leopard & clouded leopard) and ‘the rest’. In other words, domestic cats are not particularly closely related to lions, despite the iconography above.

Taxonomists have found classifying the various felids a difficult problem, due to the paucity of recent fossils (notwithstanding the classic sabre-toothed cats of the Pleistocene), a shortage of distinctive skeletal features, & some confusing distirbution patterns. Johnson & his team obtained sequences from autosomal and X- and Y-linked genes, plus mitochondrial DNA, for a total of 39 gene segments, which they then compared across all living cat species. A group of 7 distantly-related species – including hyaenas, which are more closely related to cats than to dogs - made up the ‘outgroup’, something that’s used in a phylogenetic analysis in order to distinguish between ‘ancestral’ & ‘derived’ features. (Basically, if a feature is found in the outgroup as well as the group of interest, then it’s likely to be ancestral & so won’t be particularly informative about patterns of evolution in your study group.) And the molecular dates were calibrated using 16 sets of fossil remains. 

The team found that the 8 major cat lineages evolved relatively quickly, over about 4.6 million years. Between6.4 & 2.9 mya these lineages in turn underwent a fair bit of adaptive radiation, at a time when sea levels were around 100m higher than they are at the moment. There was another burst of divergence 3.1-0.7 mya which produced 27 of the extant cat species. This was at a time when sea levels were on average relatively low.

The sea level part is important, because during periods of low sea level it would have been possible for species to migrate via land bridges into previously inaccessible areas. Based on their molecular data & available information on sea level changes, Johnson et al. suggest that modern cats evolved in Asia with that divergence between the big cats (Panthera) and all other feilds.Somewhere between 8.5 & 5.6 mya the ancestors of caracals, servals & golden cats arrived in Africa. Then, between 8.5 & 8.0 mya felids arrived in North America for the first time via the Bering Strait land bridge. This immigrant group seems to have been the common ancestor to ocelots, puma, leopard cats, lynxes – and the domestic cat. When the Panamanian land bridge formed 2.7 mya this opened up more new ecological opportunities for the feline explorers.

Subsequently there were other migrations back from the Americas to Eurasia & then further west. Cheetahs, for example, are now found in Africa, but the genetic analyses by Johnson’s team indicate that their closest relatives are the North American pumas. Similarly members of the genus Felis must have crossed back into Eurasia at least once, given that the domestication of the common moggy seems to have occurred in the Near East, at about the same time that agricultural settlements were developing in the Fertile Crescent (Driscoll et al., 2007) (Other American species moved across the Bering land bridge to Eurasia, & hence Europe, at various times – most notably the various horse species. The fossil remains of this particular sequence of species migrations were interpreted by T.H.Huxley as evidence for a European origin of the horses, a view he rapidly & happily relinquished when presented with evidence of the horses’ long evolutionary history in America.)

Once more – that simple linear iconography is not a scientific representation of feline evolution, and a long way from the much more complex and fascinating reality.

C.A.Driscoll, M.MenottiRaymond, A.L.Roca, K.Hupe, W.E.Johnson, E.Geffen, E.H.Harley, M.Delibes, D.Pontier, A.C.Kitchener, n.Yamaguchi, S.J.O’Brien & D.W.Macdonald (20008) The Near Eastern origin of cat domestication. Science  317: 519-523

Johnson, W., E.Eizirik, J.Pecon-Slattery, W.J.Murphy, A.Antunes, E.Teeling & S.J.O’Brien (2006). The Late Miocene Radiation of Modern Felidae: A Genetic Assessment Science, 311 (5757), 73-77 DOI: 10.1126/science.1122277

contaminated dietary supplements Alison Campbell Jun 19

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Trawling through my ‘blogging’ folder, wondering what to write about, I came across a paper from the New England Journal of Medicine that discusses problems with contaminated dietary supplements in the US (Cohen, 2009). I’ve previously written about the recall of ‘natural’ treatments for impotence, & Grant’s talked on more than one occasion for the need for ‘truth in labelling’ for such supplements & other forms of complementary & alternative medicine. So I thought it was about time for a follow-up.

Every so often the issue of regulating complementary & alternative health products comes to the fore in NZ. And when it does there are usually fairly strident arguments made against the suggestion. I’ve never really been able to understand why, given the evidence that these products can be adulterated, or aren’t standardised in terms of dosage. I’m also at a loss to see how some (many?) of these products can be described as ‘natural’, and held to be much better for you than those made by ‘Big Pharma", when in fact they’re often (as we shall see) not all-natural & also often produced by the same pharmaceutical companies that make prescription drugs.

Cohen’s paper begins with the cautionary tale of an American police officer who took what was presented as a ‘natural’ weight-loss supplement to help him lose some excess kilos. The supplement also lost him his job – it contained amphetamine, which was detected in a routine urine test & led to him being fired. Apparently, by August 2009 the US Food & Drug Administration had identified more than 140 ‘natural’ products containing active pharmaceutical ingredients, most of them marketed as dietary supplements – & this is regarded as the tip of the iceberg.

Apparently, before 1994 herbal products fell under the rubric of food additives; manufacturers had to prove their products were safe before they could market them. These days, since the 1994 US Dietary Supplement Health & Education Act, it’s assumed that supplements are safe & there’s little control over their marketing. However, it seems that this deregulated environment isn’t well understood by either consumers or doctors. The majority of consumers believe that the supplements they take have been approved by the relevant government agency, & must carry warning labels about any side effects that may exist. (The absence of such warnings is then taken to mean that the product is safe, where in fact they may simply be missing.) Similarly, a survey of doctors in training found that a large minority also believed that the products had to have FDA approval, while most didn’t know that adverse events had to be reported to the FDA.

Cohen’s list of contaminants found in ‘health’ products on the US market is alarming. While poisonous plant materials, heavy metals, & bacterial contamination are commonly found, what’s even worse are the many supplements – touted as ‘natural’ – that contain ‘prescription medications, controlled substances, experimental compounds, or drugs rejected by the FDA because of safety concerns’ (Cohen 2009). They’re most often detected in products sold to enhance sexual or athletic perfomance, or for weight loss but are also found in supplements aimed at people with serious health concerns, such as diabetes. In the light of all this I find it more than a little ironic that a New Zealand natural health products website – arguing against regulation of these products in NZ – says that "the status quo, mirrored in the USA, has been shown over many years to be safe, inexpensive and efficacious. Existing legislation protects consumers from dangerous products and misleading advertising." As Cohen has pointed out, this is a long way from reality. 

Given patients’ tendency not to tell their GPs what supplements they are using (unless the doctor asks fairly specific questions), & the fact that some supplements can act as antagonists to prescription medicines**, & that the contaminants themselves can have serious health effects, such widespread contamination may well represent a significant public health risk in the US (where it’s estimated that 114 million Americans use some sort of dietary supplement: Cohen, 2009)). And in New Zealand. You might argue that ‘our’ products are much better formulated – but remember that many supplements are readily available on-line from overseas sellers, or are imported from overseas and, as the recent withdrawal of sexual enhancement products shows, may be subject to the same serious problems as those discussed by Cohen.

Personally, I think there’s a good argument for regulation of dietary supplements & other over-the-counter health products. You may argue that it’s a case of ‘buyer beware’ & individual freedom to choose – but there’s likely to be a significant cost to the individual and to the public health service when (& it is when, rather than if) things go wrong.

** For example, Oneschuk & Younus (2008) note that while some ‘natural health products’ may have the potential (based on animal & in vitro studies) to help cancer patients manage the side effects of chemo- & radiotherapy, others significantly reduce the effectiveness of chemotherapeutic drugs.

PS (23/06/2010) Anyone interested in a more detailed coverage of the US situation should have a look at Steven Barrett’s post on Quackwatch.

P.A.Cohen (2009) American roulette – contaminated dietary supplements. New England Journal of Medicine 361(16): 1523-1525. doi 10.1056/NEJMp0904768

D.Oneschuk & J.Younus (2008) Natural health products and cancer chemotherapy and radiation therapy. Oncology Review 1: 233-242. doi 10.1007/s12156-008-0028-6 

helping students engage with maths & physics Alison Campbell May 17

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OK, not biology :-) But what follows could equally well apply to teaching problem-solving in any of the sciences.

A colleague of mine (thanks, Jonathan!) sent me through the link to a talk by Dan Meyer, on teaching maths & physics. Dan’s talking about how to engage students with the subjects he teaches; how to put them on a level playing field – where they can all understand what a question’s about; how to get them talking about the question in a way that guides them to understanding how to get at the answer in a meaningful way. His aim: for all his students to become ‘patient problem-solvers’. His hope: for textbook authors to develop resources that support this aim instead of obfuscating it. Enjoy.

PS while the lecture’s aimed at high-school teachers, I would argue that university lecturers teaching in maths & physics should also be watching it. After all, they teach the teachers :-)

knowledge vs certainty Alison Campbell May 16

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From time to time (well, OK, quite often!) I write something about the nature of science. One of the things that I think is often misunderstood is that science is not about certainty, it’s about knowledge. Because we are constantly adding to our understanding of how the world works, we’re never 100% certain about our findings. 99.9%, maybe, but there’s always the possibility that new data may make us question that :-) The trouble is that humans seem to want certainty, & if you’re craving that certainty, & don’t understand why science can’t give it to you, then it’s easy to deny the science in favour of some other ‘way of knowing’.

Anyway, Orac has just written a great post entitled Knowledge versus certainty in skepticism, medicine, & science. It’s based on a research paper examining people’s reluctance to change particular beliefs when presented with ‘belief-challenging’ scientific information. I found it a fascinating read :-)

putting therapeutic touch to the test Alison Campbell May 08

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It’s ’science fair’ time of year again & I’ve volunteered to be a judge at the local fair. I’ve always enjoyed science fairs, starting from way back when my siblings & I regularly entered in the Hawkes Bay event. It’s great meeting a whole bunch of up-&-coming young scientists, & they do some wonderful projects. Some of which, like Emily Rosa’s examination of ‘therapeutic touch’, go a very long way indeed.

When she was nine years old, Emily Rosa was casting around for a science fair project when she saw a video about ‘therapeutic touch’ (a practice which seems to be rather widespread in the US public health system if Orac’s posts are anything to go by). The basic assertion of therapeutic touch (TT) is that everyone has an ‘energy field’ that extends beyond the body, and that TT practitioners can detect this field and influence it in a healing way when they move their hands in that field without actually touching the skin. This apparently removes ‘blockages’ in the energy flow, removes pain residues in cells, all sorts of stuff. (Given that sensations of pain are due to electrical activity in nerve cells, it’s hard to see how there can be any left-overs elsewhere. It’s thus rather difficult to see how a modern US hospital could make such statements on its website.) Emily came up with a simple, elegant way to test the claim that such a field existed and could be detected by a practitioner’s hands. Her initial results were presented in her science fair project & caught the interest of a scientist who suggested a further round of tests – the result was a paper in the Journal of the American Medical Association, published 2 years after Emily did her original project. Not bad for someone still in primary school!

Emily contacted 15 therapeutic touch practitioners & explained that she was hoping they’d help with her school science fair project; they all agreed. Her protocol was very simple: she used a screen with holes through which her subjects extended their hands – they couldn’t see what Emily was doing on the other side of the screen. Using a flip of a coin, she randomly decided which of the subject’s hands she would hold her own hand over, and then asked each subject to state which of their hands detected her ‘energy field’. Each person had 10 attempts at this – but failed to do better than would be expected on the basis of chance.

Subsequently, it was suggested that Emily might like to do a second round of sampling with an eye to writing her results up in a scientific paper (helped in this by her parents & a medical doctor). She approached 13 TT practitioners (including 7 who’d taken part in the earlier project) and asked if they’d participate, making it clear that this was for a research paper & that the proceedings would be videotaped for this purpose, so there’s no question (as has been suggested by some critics) that they were fooled into thinking it was ‘just’ a kid’s sci-fair project.

Again the practitioners failed to fire – taking all Emily’s data together, the success rate was only 44%. Tellingly, she asked some practitioners to hold her hands before the tests to determine which hand had the higher ‘energy field’, & then used that hand only – it made no difference to the outcome. Yet you’d expect at least 50% for chance alone – if TT worked the % success should be much higher. As the paper notes: The statistical power of this experiment was sufficient to conclude that if TT practitioners could reliably detect a human energy field, the study would have demonstrated this (Rosa et al. 1998).

And the JAMA paper concludes:

Twenty-one experienced TT practitioners were unable to detect the investigator’s “energy field.” Their failure to substantiate TT’s most fundamental claim is unrefuted evidence that the claims of TT are groundless and that further professional use is unjustified.

In the PBS archives there’s a rather fascinating Q&A session that Emily did with (mainly) other students; definitely worth a read & it shows her to be a mature young woman with a strong scientific bent. You might also like to listen to Brian Dunning’s take on the whole therapeutic touch thing, over on Skeptoid.com.

It just goes to show, age doesn’t matter if you’re doing good science.

L.Rosa, E.Rosa, L.Sarner & S.Barrett (1998) A close look at therapeutic touch. JAMA 279: 1005-1010

sensing nonsense Alison Campbell May 07

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The idea for this post comes via the team at the most excellent Silly Beliefs blog: Stuff (repository of news & what looks like an awful lot of other stuff) reported about a Massey University research project. The Stuff report kicks off by saying

Spirits are increasingly making their presence felt in New Zealand, spurred on by celebrity ghost whisperers.

Hmmm. I have to say, what first came to mind was the Dr Who episode where the good folks at Torchwood had been fooling around with the space-time continuum, so that cybermen were pushing through from some other dimension, & people were interpreting their partial manifestations as ghosts. (It all turned to tears, even for the Doctor, although he did eventually save the day.) But here I am, getting side-tracked again. Back to the chase!

The Stuff item goes on to say:

Massey University research reveals growing numbers of Kiwis are sensing spirits. In a recent survey, the proportion of respondents who have felt a spiritual force rose from 33 per cent in 1991, to 40 per cent.

So I trotted off to Google Scholar – couldn’t find any published papers that matched the Stuff description, so I must assume that their breathless article was based on a press release. Going by said article, it appears that the researchers were looking at New Zealanders’ beliefs about the existence of ghosts/spirits. Among other things, they seem to have found that around 50% of people are ‘interested in spiritual forces’ (not quite the same thing as ’sensing’ them), while 25% believe that ‘the dead have supernatural powers.’

Now, that’s about all that can be inferred about the research, so I’m not going to discuss that further here. What I do want to do is look at the way the findings were portrayed by Stuff (& presumably by other media outlets who picked up the story). Listen up, Stuff: a statement by x% of respondents that they believe in a spirit world is NOT THE SAME as spirits actually existing! The researchers seem to have been examining changes in beliefs or belief systems, not accumulating data to test the idea that the object(s) of belief are real. The fact that somone claims to believe in ghosts does not mean that ghosts exist. The great (& unfortunately late) Carl Sagan commented in The demon-haunted world that he could claim that there was an invisible dragon living in his garage. A sceptical response to this claim might be, sorry, can’t see anything. Ah, said Sagan, but what if I said it’s an invisible dragon?

The lead researcher is also quoted as saying

Programmes like Sensing Murder and Ghost Whisperer have popularised psychic experiences that in previous times would have been dismissed as symptoms of psychosis.

The Sensing Murder psychics have almost become spiritual celebrities.

First up, I suspect that it’s only fairly recently that anyone claiming to see ghosts & spirits would have been encouraged to have a quiet chat with a psychiatrist. Go back a few hundred years and someone making these claims might instead have been treated with respect (& in some societies that’s probably still the case).

What’s more, where’s the evidence? Stuff makes the fascinating claim that [s]pirits are increasingly making their presence felt in New Zealand without any real data to support it. Where’s the cold, hard, unequivocal evidence that a ghostly presence has indeed made itself felt? And I don’t mean via self-professed psychics, either. Why would a ghost need to be ’spurred on’ by ‘celebrity ghost whisperers’ or anybody else, if they really wanted to contact the living? Particularly when as interpreted by said ghost whisperers, they say such inane things… (Not to mention the cost – why would your dearly departed wish to speak with you only after you’ve forked out a reasonable amount of money? For those who think, there might just be something in what psychics claim to be able to do – you might just want to read this article on ‘cold reading’ and other tricks of the trade.)

On the thoughtful, investigative journalism scale, the Stuff item deserves an F.

academic language & learning about science Alison Campbell May 03

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One of the biggest challenges faced by students of biology (or any science, really) is coming to terms with the language of science. Scientific language is precise, it’s concise, and it uses a dauntingly large number of new terms. (I saw it written somewhere – sorry, too much marking & the memory’s gone bad! – that learning the last is like learning French or some other foreign language.) Going by the conversations I’ve had with some of my first-year students, just that overwhelming number of new words can be enough to make some people seriously reconsider taking the subject. Which is kind of sad, really – & one reason why I always take a great deal of care in my lectures to introduce new terms carefully & explain what they mean & how we use them. (OK, maybe not every new word, but at the very least, the ones that I know they have trouble with.) It also highlights the fact that it’s so very important to be meticulously careful in how you use words, when communicating about science with a wider audience. While the language can add precision, its sophistication & complexity can also be a real barrier to understanding (Snow, 2010).

Catherine Snow (2010) comments that what we call ‘academic language’ – something that all university students are expected to master, albeit in the form required by their own particular discipline – tends to be concise, lacking in repetition, with a high number of ‘information-bearing’ words that allow it to be very precise, and wtih a particular set of grammaticial rules. (Most of which I break, here, on a regular basis LOL). This works just fine when you’re communicating with someone else who understands the rules of engagement, but it can be a long way from the ease & simplicity of everyday speech patterns.

Thinking about it, this is probably one of the reasons that the Cafe Scientifique movement is successful – because the organisers take care that the scientists who speak at these events are well aware that they need to present to a general audience, & to keep the jargon to a minimum. In some ways the lack fo powerpoints & so forth probably aids this, too, as it’s all to easy to fill a screen with lovely long scientific words & totally lose your audience in the process. But I digress…

Well, no, I don’t really, Because Snow points out that the habits & characteristics of oral language probably are more accessible to the non-scientist. Sentences often begin with pronouns, so the listener/reader can be drawn in  rather than held stiffly at arm’s length. Verbs really are ‘doing’ words, and if you’re getting a lot of information across, it tends to be in a sequence of ideas rather than a whole bunch of embedded clauses. (OK, I know I do that sometimes.) All too often, perhaps, a piece of written academic scientific prose can come across as impersonal, distanced, authoritative, & too full of those scary new words – this can be off-putting to newcomers, & I know from experience that it’s extremely hard for new students to produce their own written work in the same register (desirable though that may be to their lecturers). They actually need a lot of support and multiple opportunities to practice, if we want them to be able to deliver the desired standard of work on a regular basis.

And it’s not just enough to teach the vocab. This is particularly the case if the definition of a new term includes other, widely-used scientific words that the student doesn’t know either! Snow gives the example of a piece of physics text: ‘Torque is the product of the magnitude of the force and the lever arm of the force.’ Now, I have a fairly good grasp of terms like ‘magnitude’, & I know what a ‘lever’ is, so I can work that one out. But to a new student, ‘product’ & ‘arm’ & ‘force’ have other, general meanings, & if they apply those meanings to the academic definition, they will be in all sorts of strife and misunderstandings & misconceptions will almost certainly follow.

Yet students who are going to progress in science really do need, eventually, to learn to write (& speak, in oral presentations anyway) in the complex formal register of science. The devil, of course, is in the detail of how we get them there. Snow argues – & I agree completely – that this needs to be embedded in the science curriculum (ideally, before students arrive at uni, but certainly at university level). The obvious questions are, how, and what do we leave out in order to do this? (Myself, I’m not convinced that we necessarily have to leave things out, but do have to change the way we teach. Material for another post, methinks.)

And hopefully the best of those students will end up with the best of both worlds – an ability to communicate within the science community, and the skills to translate from that to the wider community beyond the walls of academe.

C.E.Snow (2010) Academic language and the challenge of reading for learning about science. Science 328: 150-452. doi: 10.1126/science.1182597

chemo vs cancer, science vs disease Alison Campbell Apr 24

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In another few weeks it’ll be 27 years since my mother died of metastatic breast cancer. Not a nice way to go – but eased by a very caring family GP and the wonderful people at the local hospice, who helped her die with dignity at home.

I was reminded of this by reading David Gorski’s recent post on Science-Based Medicine: chemotherapy vs death from cancer. In the US at least (although I suspect here as well), ‘alternative practitioners’ offer a wide range of ‘therapies’ for people with cancer, claiming ‘natural cures’ & the option of ‘dying healthy’ if you must die at all. Unfortunately for those choosing this option, modern chemotherapy really is the best treatment option for many cancers (alongside radiotherapy & surgery, depending on how the disease manifests itself). If those alternative therapies worked they’d have become part of the mainstream pharmacopaeia by now. Dr Gorski agrees that yes, chemo can be quite brutal in its effects – but the cancers it is aimed at are at least as bad. (The reason chemo can have serious side effects is that it’s a fine line between killing the cancerous cells & killing normal tissues.)

Anyway, Dr Gorski’s article led me to think about the way that other proponents of ‘alternative therapies’ make special claims for their own products, and level all sorts of accusations against mainstream medicine. Over on SciBlogs, for example, a local anti-vaccination advocate was quoted in the comments thread for an article on vaccination that the sooner New Zealand drops all vaccinations, the better. In support of their views that vaccinations are Bad, Bad, Bad, the commenters on that thread trotted out all the usual claims: that vaccines cause autism (false – there are no data to support this claim); that vaccines contain ‘neurotoxic’ materials including formaldehyde (true, but our bodies make far more of this, during normal metabolic processes, than is contained in any dose of a vaccine); that vaccines contain ‘aborted foetal tissues’ & ‘monkey kidneys’ (serious scare tactics, these, & also false). These claims have been ably addressed elsewhere, both on SciBlogs & on overseas sites such as Science-Based Medicine & Orac’s Respectful Insolence.

But I wonder - do the people advocating a complete cessation of vaccination really seriously think about the consequences of this? My mother contracted polio as a teenager in the 1930s. She was lucky – the virus ‘only’ paralysed nerves in her hand and leg. She recovered, but for the rest of her life the muscles in those areas were smaller & weaker than on the unaffected side. She never had to spend time in an iron lung – and at the height of polio epidemics, some overseas hospitals had entire wards devoted to patients in these machines, which ‘breathed’ for people who could no longer breathe for themselves because the necessary muscles were paralysed. Mortality rates from polio – before the widespread availability of a reliable vaccine – were around 5%, with a further 35% of those infected suffering some level of paralysis.

Or what about diphtheria? The mortality rate for this bacterial disease is between 5 & 10%, & outbreaks still occur, even in industrialised nations. Diphtheria often has respiratory symptoms, due in part to severely swollen lymph nodes in the neck. But the bacterium (Clostridium diphtheriae) also produces metabolic by-products that can lead to damage to the heart & nerves, & it can sometimes cause serious secondary infections in the skin.

And there’s measles, whooping cough, rubella – while in the industrialised world, with its generally good provision of health care, most of those who contract these infections go on to recover, they are not trivial diseases. (I couldn’t believe one comment I read a few months ago, where the writer commented that whooping cough was a trivial illness; her child had ‘only’ had a serious cough for a week… & was unwell for several more.) All have a rate of serious complications, including death, that is several orders of magnitude higher than the unquestioned rate of complications due to vaccination.

And I wonder – are people so ready to advocate a return to a world where these diseases are common because they’ve never had first-hand experience of the effects? After all, the highest rates of illness occur in the ‘third world’, which is a long way from the experiences of most people in comfortably first-world New Zealand. And is part of it due to a failure on the part of scientists, doctors, the education system at large to help people understand things like relative risk, and how science-based medicine operates? And – a key part of this – how well do we communicate the idea that correlation does not equal causation: that because B happens soon after A, for example, this is not proof that A caused B?

I think we still have a long way to go on these things.

______________________________________________________________________________

PS And those with a genuine interest on what <i>is</i> in vaccines (as opposed to the wilder claims being made over at Sciblogs) might like to read this post from ERV:  – basically a group of researchers did DNA analysis on most of the main vaccines, looking for evidence of contamination from other sources (monkey tissue, foetal tissue, etc etc). The result: modern vaccines are clean.

what evolution is Alison Campbell Apr 22

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The issue of who’s going to coordinate our 2nd-year evolutionary biology paper came up the other day. (I haven’t done it for the last couple of years as my ‘other’ job - in the Dean’s office – takes up a fair proportion of my time. But at some point I’d like to get back into it.

We’ve had that paper, Evolution and Diversity of Life, on the books for a long time. When I first came here it was more of a diversity course, looking at the different plant & animal taxa, & while the topic of evolution was there it was more implicit than explicit at times. When I took over as coordinator I left things as they were for the first year or so, while I looked at content, curriculum & all that. And then, with several colleagues, I brought in changes that meant that we are now much more explicit in our teaching of evolution. This is because we’d found that many students weren’t really clear on what the word evolution actually means.

So we changed things to help them find out – there’s a lot of research out there showing that simply telling students ’stuff’ (be that concepts in electronics or ideas in evolution) has hardly any effect on their understanding of the material. Getting them interactively involved, on the other hand, can work wonders. Story-telling’s good, too – with a concept like evolution, simply telling students ‘this is what it is’ isn’t particularly helpful in enhancing their understanding. But using narrative to show the history of how the theory of evolution developed, now that can make a difference.

And for a major concept like evolution, which underpins all of modern biology, it’s really important that students have a good understanding of what it means.

Evolution can be used in three inter-related ways. First up, evolution is a fact. There is now a very large body of evidence supporting the understanding that all living things have evolved through a process that Darwin characterised as ‘descent with modification’ from some common ancestor. Biogeography, palaeontology, embryology, molecular biology; all provide evidence of the fact of evolution.

People can also talk about evolutionary history – the pathways by which organisms arrived in their current state. I’ve written before about the evolutionary pathway of vision (here & here, for example) and of the tiny middle-ear bones in mammals (which are derived from bones in the reptilian jaw articulation). These days a lot of those evolutionary relationships are elucidated using comparisons of DNA sequences (& those of you sitting L3 Biology this year will have seen some of the cladograms, or ‘family trees’, that this work generates), but the fossil record has provided & continues to provide a significant amount of information. For example, both fossil evidence & DNA data support the idea that the most recent common ancestor of humans and chimps lived around 5-7 million years ago.

And of course, there’s the theory of evolution. Theory in the strong scientific sense of a cohesive explanation for a large body of data, which is consistent with those data and which provides testable predictions. The theory of evolution offers a mechanism by which the fact of evolution has occurred and which underlies those evolutionary pathways. (That should read ‘mechanisms’ really: while Darwin’s original mechanism, natural selection, is a key player, genetic drift also has a role to play.)

So there you are: what evolution is. And why we should take care to teach it carefully and well.

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Anyone interested in a bit of extra reading might want to have a look at Evolution: the first four billion years. Haven’t read it myself yet (apart from the intro, which shaped my thinking for this post) but it’s been recommended to me.

M. Ruse & J. Travis (eds.) (2009) Evolution: The First Four Billion Years. Belknap Press

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