Archive 2011

homeopathy is ‘personalised’? Alison Campbell Dec 31


Orac has just put up a post deconstructing various claims by a US homeopath. One of those claims really tickled my fancy:

The problem is that homeopathy is aimed at treating the individual with a single remedy, chosen specifically for him or her. It is not for treating masses of people with the same pill. Twenty people could have the “same” flu, but each one would need a different remedy (not necessarily Oscillococcinum) and be rightly cured because each one would manifest illness in a way that is utterly unique to him-/herself. We always treat the person, not the disease. As such it is exceedingly difficult, if not impossible to replicate homeopathic treatment the way pharmaceutical companies try to do in drug trials.

If this is the case, you really have to wonder why many pharmacies even bother to offer those rows of homeopathic ‘remedies’ on their shelves. After all, if our homeopath is correct, those commercial potions couldn’t possibly work…

(The article is well woth a read – the various metaphors this practitioner uses in attempts to explain the unexplainable are rather entertaining.)

the status & quality of year 11 & 12 science in australian schools Alison Campbell Dec 21

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My reading assignment today was a report just out from the Australian Academy of Science (the AAS) on science in Australian secondary schools (Goodrum, Druhan & Abbs, 2011). Not what you might expect on a reading list in the week before Christmas, but I was up to speak (briefly) about it on Radio NZ & needed to have an idea what the report contained.

It’s a really thorough study of the state of senior school science across the Tasman, based on an extensive literature review, a survey of students (both those taking science, & those who aren’t) in NSW, South Australia & the Australian Capital Territory, a phone survey of senior science teachers in the same states, and a series of focus groups involving not only teachers and students but also scientists & members of the wider community. This allowed Goodrum & his colleagues to describe the ideal state of senior school science education in Australia (my marginal note at this point says ‘Wonderful! but does it/can it happen?) in terms of students & the curriculum, teaching as a profession, the resourcing of science teaching & learning, and the value of science education. They describe the last item thusly:

Science and science education are valued by the community, have high priority in the school curriculum and science teaching is perceived as exciting and valuable, contributing significantly to the development of persons and to the economic and social well-being of the nation.

And then… they identified the actual state of affairs, “by focusing on different dimensions of the school experience: the students, the curriculum, the pedagogy, the teachers and finally the resources.”

I must say that I think we are well ahead of the Australian state of play in terms of the curriculum document as discussed in the AAS report: Yes, the NZ curriculum is probably still too content-heavy, but at least the clear understanding and expectation is that senior school science should do much more than simply prepare a relatively small cohort of students for university. (This is something that I believe the universities need to be much more aware of, as otherwise we will continue to have a disjunction between lecturer expectations and the actual prior learning experiences of our new first-year students.) Also, the NZ Science curriculum explicitly requires that students be given the opportunity to learn about the nature of science; it’s not all about content knowledge. However, the AAS survey found that both students and teachers in the Australian school system believed that

Year 11 and 12 science is constructed to prepare students for university study. This university preparation perspective has resulted in an overcrowded content-laden curriculum. WIth the amount of content to be covered there is little room for flexibility from either the teacher or student.

Goodrum & his colleagues also found that most senior science teaching** in the schools they surveyed is done using the transmission model (teacher talks or writes on the board – or uses powerpoint – & students simply write it all down); that teacher demonstrations are common; and that practical sessions tend to be of the ‘cook-book’ variety where the outcomes are already known and the students are simply following a pre-determined method. Where there is opportunity for more inquiry-based learning in labs, teachers reported that these really sucked through the time & that this in turn led schools using open-ended student projects to advise students not to take all three sciences as the demands on their time would be too great.

So what did they find when they looked at levels of participation in senior science: the proportion of students in each year’s cohort who were enrolled in science subjects in their final 2 years of secondary school? The news was not good, and it’s news that’s obviously generating a lot of concern: looking at the proportion of students enrolled in each discipline in each year, they found that

[s]ince 1991, the percentage of students enrolled in Biology, Chemistry and Physics has been gradually falling. For Biology the fall has been from 35.9% in 1991 to 24.7% 2007, for Chemistry 23.3% in 1991 to 18.0% in 2007, and for Physics 20.9% in 1991 to 14.6% in 2007. While the fall has slowed there is no indication that it has stopped.

(The proportion taking Psychology, on the other hand, has almost doubled – from 4.9% in 1991 to 9.2% in 2006. Geology – this in a country where mineral resources are so significant to the economy – has remained at a fairly constant 1% throughout the study period.)

And looking at total science enrolments in Year 12:

there has been a dramatic fall in the percentage of students studying science in Year 12 from a height of 94.1% in 1992 to a low of 51.4% in 2010

with a particularly large drop-off in the period 2001-2002. The researchers weren’t able to identify any reason for this in terms of policy changes. Part of the decline may be linked to how students perceive science in schools – something that probably needs to be addressed in junior schools, because

Some non-science students report that if science was more ‘interesting and relevant to their lives’ then they would consider enrolling in it… Many, however, think so poorly of their experience and achievements in junior secondary science** that they won’t consider senior science under any circumstances.

This is a real pity, as the community members surveyed clearly felt that all students need to study science throughout their schooling – it shouldn’t be just for those who need it for their careers. They felt that science in schools

should be relevant… and demonstrate how science understanding and process impacts daily life.

Which is great – but I did wonder if those sentiments are shared by the wider school community as a whole (parents, teachers, students, the works). Schools do seem to be under pressure to broaden their curriculum, which places time constraints on teachers in the various subjects, & at least some of that pressure comes from the communities in which the schools are situated.

Correction: So how do the Australian data stack up compared to senior science education in New Zealand? I gathered from my radio host that the PM’s Chief Science Advisor, Sir Peter Gluckman, will be soon releasing a report on just this issue. Watch this space. It seems that the host (& I) are a bit ahead of things here *blush*. However, while they don’t have any active projects in this area, the Chief Science Advisor & his office are very supportive of Ministry of Education initiatives introduced in response to an earlier report by Sir Peter.

** The researchers make the point that this is different from the teaching methods used in junior (our years 9-11) science classes, and suggest that “[p]erhaps this more enlightened approach in the junior years should influence how science is taught in Years 11 & 12.” (Some students obviously gained a different impression…)

D.Goodrum, A.Druhan & J.Abbs (2011) The Status and Quality of Year 11 and 12 Science in Australian Schools. A report prepared for the Office of the Chief Scientist.

letters to the editor: science & god Alison Campbell Dec 20


From today’s “Letters to the Editor” in today’s NZ Herald:

Your correspondent correctly states that Charles Darwin’s theory of evolution is under threat.

The main threat, however, is not coming from “conservative religious school.” It is coming from science.

Well, as a scientist, this is news to me. What scientific evidence does our correspondent present in support of this supposed ‘threat’?

In the past decade, especially, incredible advances in micro-imaging have revealed the amazing interior of our body’s cells among many other biological wonders. The stupendous complexity of these microscopic structures is leaving scientists flabbergasted.

None of the biologists I know could be described as ‘flabbergasted’ (adj: “overwhelm[ed] with shock, surprise, or wonder“) as they learn more of the cell’s fine internal structures. Not in what I suspect is our writer’s intended sense, of being so shocked & surprised that they’re ready to throw out all they know about evolution & how it functions. (I wonder if by ‘micro-imaging’ he means videos like this one, which is an animation developed by XVIVO for Harvard University.)

Just as a taster, Google “bacterial flagellum” and discover an acid-powered motor inside the cell with a shaft through the cell wall fitted with a propeller that moves the cell about.

I did – & the first entry on the search page is this one from Wikipedia, which gives a clear, factual description of the current state of knowledge of flagellum structure and function. Incidentally, the flagellum evolved at least three times, in Archaea and the ‘true’ bacteria, and in eukaryotes (the group that includes plants, animals, fungi, & single-celled organisms) – you have to wonder why our writer’s designer would tinker like that…

His description of the ‘motor’ is intriguing. The ‘acid-powered motor’ is a complex of proteins, & its movement is powered by the movement of hydrogen ions across a membrane (in the same way that production of ATP in mitochondria uses movement of H+ ions). The word ‘propeller’ may be intended to conjure up images of a boat’s propeller (with all its connotations of a designer), but the flagellum looks nothing like that.

While we’re on the flagellum, our writer seems unaware that the idea that this example of ‘intelligent design’ was comprehensively dismissed during the ‘Dover trial‘. Yes, I know he doesn’t come out and use those words or the term ‘specified complexity’ (hinted at in his next paragraph), but his intent is clear – there’s a designer. Ken Miller has written a clear overview of the whole argument about flagellal origins.

Mathematicians have determined there is no way that such complex structures could accidentally self-form, as required by Darwin’s theory, within the entire life of the universe, let alone in a paltry few millions of years.

Which mathematicians? Jason Rosenhouse has written an interesting post on the issue of improbability & evolution. He notes that those espousing our writer’s view “typically toss off combinatorial arguments in which the probability of evolving some complex molecule, like haemoglobin, is taken to be one over the number of ways of arranging the amino acids in that molecule. Sadly, that only works if all of those arrangements are equiprobable, but the continuing action of natural selection ensures that they are not.” And this is another point where the letter’s author goes wrong, because the process of natural selection is not ‘accidental‘. (He also seems unaware of the antiquity of life on Earth: bacteria have been around for up to 3.5 billion years – orders of magnitude greater than his ‘paltry few millions.’)

“Origin of Species”, written 150 years ago by Darwin, is incorrect and we must be more open-minded when teaching children how we might have got here.

Of course there were things Darwin didn’t know – in the absence of any knowledge of genetics, or of cell ultrastructure, at the time when he was writing, how could it be otherwise? But this does not detract from his magnificent insight, meticulously documented, that evolution by the process of natural selection could account for life’s wonderful diversity. That concept has been tested, and confirmed, and extended, time and time again since the Origin was first published.

There’s an important point to be made here. Just because science can’t currently explain something, does not mean scientists won’t be able to explain that phenomenon in the future. If the response to something novel was always “I can’t imagine how that might develop, therefore God”, then we would never have reached anything like our current understanding of how the living world operates. And we would be the poorer for it.

using pseudoscience to teach science Alison Campbell Dec 20


The following post is an article that I originally wrote for the New Zealand Science Teacher journal (the official journal of the New Zealand Association of Science Educators), and is reproduced here by kind permission of the editor.

We live in a time when science features large in our lives, probably more so than ever before. It is  important that people have at least some understanding of how science works, not least so that they can make informed decisions when aspects of science impinge on them. Yet pseudoscience seems to be on the increase. While some argue that we simply ignore it, I suggest we use pseudoscience to help teach the nature of science (and I recommend Jane Young’s excellent book, The uncertainty of it all: understanding the nature of science,(2010) as a resource).

The New Zealand Curriculum (MoE, 2007) makes it clear that there’s more to studying science than simply accumulating facts: Science is a way of investigating, understanding, and explaining our natural, physical world and the wider Universe. It involves generating and testing ideas, gathering evidence — including by making observations, carrying out investigations and modeling, and communicating and debating with others — in order to develop scientific knowledge, understanding and explanations (p28). In other words, studying science also involves learning about the nature of science: that it is a process as much as, or more than, a set of facts. Pseudoscience offers a lens through which to approach this.

1. Check the information
Students should be encouraged to think about the validity and reliability of particular statements. They should learn about the process of peer review. They should ask: has a particular claim been peer reviewed; who reviewed it; where was it published? There is a big difference between information that’s been tested and reviewed, and information (or misinformation) that simply represents a particular point of view and is promoted via the popular press (and Internet).

‘Cold fusion’ is a good example. Cold fusion was a claim that nuclear fusion could be achieved in the laboratory at room temperatures. The claim was trumpeted to the world via a press release, but was subsequently debunked because other researchers tried, and failed, to duplicate its findings.

Thus checking the source of the information is vital. There is a hierarchy of journals, with publications such as Science considered prestigious, and publications such as Medical Hypotheses considered less so. The key distinction between these journals is the peer review process. For example, papers submitted to Science are subject to stringent peer review processes (and many don’t make the grade), while Medical Hypotheses seems to accept submissions uncritically, with minimal review.

By considering the source of information students can begin to develop the sort of critical thinking skills that they need to make sense of the cornucopia of information on the Internet. When viewing a particular Internet site they should ask (and answer!) questions about the source of the information: has it been subject to peer review (you could argue that the Internet is an excellent ‘venue’ for peer review, but all too often it’s simply self-referential), does it fit into our existing scientific knowledge, and do we need to know anything else about the data or its source?

2. Analyse the information
The following example is excellent for a discussion around both evolution and experimental design, in addition to the nature of science. There is an online article entitled Darwin at the drugstore: testing the biological fitness of antibiotic-resistant bacteria (Gillen & Anderson, 2008) where the researchers tested the concept that a mutation conferring antibiotic resistance rendered the bacteria less ‘fit’. Note: There is an energy cost to bacteria in producing any protein, but whether this renders them less fit — in the Darwinian sense — is entirely dependent on context.

The researchers used two populations of the bacterium Serratia marcescens: an ampicillin-resistant lab-grown strain, which produces white colonies, and a pink, non-resistant (‘wild-type’) population obtained from pond water. ‘Fitness’ was defined as ‘growth rate and colony “robustness” in minimal media.’ After 12 hours’ incubation the two populations showed no difference in growth on normal lab media (though there were differences between 4 and 6 hours) but the wild-type strain did better on minimal media. It is difficult to know whether the difference was of any statistical significance as the paper’s graphs lack error bars and there are no tables showing the results of statistical comparisons. Nonetheless, the authors describe the differences in growth as ‘significant’.

The authors concluded that antibiotic resistance did not enhance the fitness of Serratia marcescens: wild-type [S.marcescens] has a significant fitness advantage over the mutant strains due to its growth rate and colony size. Therefore, it can be argued that ampicillin resistance mutations reduce the growth rate and therefore the general biological fitness of S.marcescens. This study concurs with Anderson (2005) that while mutations providing antibiotic resistance may be beneficial in certain, specific, environments, they often come at the expense of pre-existing function, and thus do not provide a mechanism for macroevolution (Gillen & Anderson, 2008).

Let us now apply some critical thinking to this paper. Your students will be familiar with the concept of a fair test, so they will probably recognise fairly quickly that such a test was not performed in this case because the researchers were not comparing ‘apples with apples’. When one strain of the test organism is lab-bred and not only antibiotic-resistant but forms different coloured colonies from the pond-dwelling wild-type, there are a lot of different variables involved, not just the one whose effects are supposedly being examined.

In addition, and perhaps more tellingly, the experiment did not test the fi tness of the antibiotic-resistance gene in the environment where it might convey an advantage. The two Serratia marcescens strains were not grown in media containing ampicillin! Evolutionary biology predicts that the resistant strain would be at a disadvantage in minimal media. This is due to it using energy to express a gene that provides no benefit in that environment, making it short of energy for other cellular processes. And, as I commented earlier, the data do not show any significant differences between the two bacterial strains.

Also, the authors work at Liberty University, a private faith-based institution with strong creationist leanings, and the article is an online publication in the ‘Answers in Depth’ section of the website of Answers in Genesis (a young-Earth creationist organisation). This is not a mainstream peer-reviewed science journal. This does suggest that a priori assumptions may have coloured the experimental design.

3. Verify the information
Your students should learn how to recognise ‘bogus’ science. To begin with, students should scrutinise information presented via the popular media (including websites) and ask: why is this happening? Another warning sign is the presence of conspiracy theories.

One conspiracy theory worth discussing relates to the validity of vaccination programmes: ’Is vaccination really for the good of our health, or the result of a conspiracy between government and ‘big pharma’ to make us all sick so that pharmaceutical companies can make more money selling products to help us get better?’

Dr A. Kalokerinos is often quoted on anti-vaccination websites as saying: My final conclusion after forty years or more in this business is that the unofficial policy of the World Health Organisation and the unofficial policy of ‘Save the Children’s Fund and almost all those organisations is one of murder and genocide. They want to make it appear as if they are saving these kids, but in actual fact they don’t.

This quote is a good example of how conspiracy theorists often use an argument from an ‘authority’. Yet it is easy to pull together a list of names with PhD or MD after them to support an argument. Try giving your students a list of names of ‘experts’ and see if they can work out their field of expertise.

Recently, New Zealand schools received a mailout from a group called ‘Scientists Anonymous’ offering an article purporting to support ‘intelligent design’ rather than an evolutionary explanation for a feature of neuroanatomy. The article was authored by Dr Jerry Bergman.

A literature search indicates that Dr Bergman has made no recent contributions to the scientific literature in this field, but he has published a number of articles with a creationist slant. So Dr Bergman cannot really be regarded as an expert authority in this particular area. Similarly, it is well worth reviewing the credentials of many anti-vaccination ‘experts’ — the fact that someone has a PhD by itself is irrelevant; the discipline in which that degree was gained, is important. Observant students may also wonder why the originators of the mail out feel it necessary to remain anonymous.

Students need to know the difference between anecdote and data. Humans are pattern-seeking animals and we dohave a tendency to see non-existent correlations where in fact we are looking at coincidences. For example, a child may develop a fever a day after receiving a vaccination. But without knowing how many non-vaccinated children also developed a fever on that particular day, it’s not actually possible to say that there’s a causal link between the two.

Another important message to get across to students is that there are not always two equal sides to every argument, not withstanding the catchcry of “teach the controversy!” This is an area where the media, with their tendency to allot equal time to each side for the sake of ‘fairness’, are not helping. Balance is all very well, but not without due cause.

For example, apply scientific thinking to claims such as the health benefi ts of homeopathy. Homeopathy makes quite specific claims concerning health and well-being. How would you test those claims of efficacy? What are the mechanisms by which homeopathy — or indeed any other alternative health product — is supposed to have its effects? Claims that homeopathy works through mechanisms as yet unknown to science don’t address this question, but in addition, they presuppose that it does actually work.

Students will have some knowledge of the properties of matter and the effects of dilution, and senior classes may be aware of Avogadro’s number. They could apply this to the claim that homeopathic remedies become more effective at higher and higher dilutions, something that, if correct, would overturn our understanding of basic chemistry and physics. The 10:23 Campaign — in which people take ‘overdoses’ of homeopathic remedies — is a humorous way of highlighting the improbability of such claims.

If students can learn to apply these tools to questions of science and pseudoscience, they will become better equipped to find their way through the maze of conflicting information that the modern world presents, regardless of whether they go on to further study in the sciences.

A.Campbell (2011) Using pseudoscience to teach science. New Zealand Science Teacher 128: 38-39

PM’s Science Teacher Prize: Dr Angela Sharples Alison Campbell Dec 17

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The Prime Minister’s Science Prizes were announced today, & among the winners was my good friend & colleague Angela Sharples, who was awarded the Science Teacher Prize. Angela & I have worked together to prepare NZ’s teams for the International Biology Olympiad since 2004, during which time I’ve seen first-hand just what a superb teacher she is, & how much time & effort, passion & care she gives to all her students. Lucky is the school that has Angela on its staff! Anyway, because I was one of Angela’s nominators & because it’s so important to recognise teaching excellence in all its forms, I thought I’d share some excerpts from her citations here :-)

Over the years I have had many opportunities to watch Angela working with students, using a wide variety of teaching tools in effective lessons that are tailored to the needs of her students. For students aspiring to join New Zealand’s Biology Olympiad team this has included organising and administering on-line tutorials - the only way to reach students from up and down the country. Angela supports all her students to reach the high academic standards that she expects, modelling these standards in her own practice and actively encouraging questioning and critical thinking. .

Angela joined the staff of Rotorua Boys’ High School several years ago, when senior Biology class sizes had been dropping for some time, and turned this around. Interest and demand are such that the school now has L1 Biology classes, and the number of students achieving excellence grades in this subject has markedly increased. She has rewritten the senior Biology curriculum and also all the internal assessment tasks, and the fact that the moderators agreed with all teacher judgements reflects how well she performed this huge job.

She also directs the Accelerate & Curriculum Enrichment program at RBHS, with a number of new initiatives that are intended to inspire younger students to continue with their science studies in senior school: for example, a 3-day geology trip for the year 9 ACE students that takes them from Waiotapu to White Island, learning about plate tectonics and volcanism as they go. In another project Angela worked with SCION staff to develop an enquiry-based learning community project for ACE students, which allowed the boys to do field research and generate valuable data that contributed to the work of the Kokako Recovery Trust.
Angela also takes her senior Biology students on residential field trips to Leigh Marine Reserve and Tiritiri Matangi Island, and to the lab-and-lecture program we run for year 13 students at the University of Waikato. As one of the leaders of this program I can say that Angela’s sound curriculum advice has been invaluable in fine-tuning this program to the needs of those attending. In fact, she is enormously generous with help and advice, providing collegial support to teachers throughout the Rotorua region and beyond.
Angela is an amazingly passionate educator and donates a large amount of her time to fostering excellence in Science education in New Zealand both regionally and at a national level, often working late at night and through the weekend. Not only is she pivotal in the New Zealand International Biology Olympiad (NZIBO) and Chair of Science OlympiaNZ but she is also a member of the Biology Educators Association of New Zealand (BEANZ) Executive Committee and a National Marker. And in the Rotorua region she freely shares expertise with colleagues in other schools, as well as being the regional tutor for Scholarship Biology.
Angela has been involved with NZIBO since its inception in 2004. Initially she was in charge of examinations and the practical training camp, but she took over as Chair in 2007. The NZIBO programme reaches out to gifted and talented biology students around the country, although its effects are much broader than this. All students taking part in the NZIBO tutorial program gain learning and problem-solving skills (in additional to tertiary-level knowledge) that will stand them in good stead in future study.
This program culminates in the International Biology Olympiad, held in a different country each year. The Olympiad attracts a huge amount of attention overseas and the competition for medals is intense. New Zealand has won medals every year since first competing in 2005, and every year the medal tally has improved and the world rankings of New Zealand students have increased, with Jack Zhou winning New Zealand’s first ever Gold medal at the 2011 event in Taipei. The international success of these students is in no small part due to Angela’s development of the training and selection programme.
Angela herself is well known and respected amongst biologists around the world and has accompanied the team and sat on the international jury six times in the last seven years. (You can look at this programme in more detail at Angela gains a huge amount of pleasure from seeing our students do so well in such a significant international competition, and I know that she is most proud of the fact that the number of students participating in the NZIBO programme has grown every year, as has the number of schools choosing to enter students since she became Chair. She has moved NZIBO out of the initial development phase and into a secure, established phase, both financially and in terms of profile, that will ensure the secondary school biology students of New Zealand benefit from this programme for years to come.
She is also having an effect – not least through working with several Universities in delivering the NZIBO program – in improving engagement between the secondary and tertiary Biology sectors. I find that her willingness to share knowledge and experiences in successful secondary teaching has had an impact on delivery of the first-year biology programs that I coordinate, with the very positive spin-off of enhancing our ability to bridge students into the next phase of their education. For this reason alone I regard her as a leader in education in this country, and for this and all the other reasons detailed above, I very strongly support her nomination for the Prime Minister’s Science Teacher’s Award.
Angela, I just don’t know how you find the time to do all this – but I’m enormously grateful that you do! And I’m looking forward to continuing to work with you as we begin the build-up to New Zealand’s hosting of the 2014 International Biology Olympiad.

convergent evolution: the pandas’ thumb Alison Campbell Dec 15

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 And yes, punctuation & grammar skillz, I has them :-) That apostrophe really is in the right place – read on to find out why.

The tale of the panda’s thumb is well-known, & an excellent example of how the action of natural selection can result in jury-rigged solutions to problems: a result that works, but not necessarily a perfect result. I first encountered it way back when, through reading Stephen Jay Gould’s wonderful book of the same name**.

A book which refers to the familiar black-&-white giant panda (Ailuropoda melanoleuca). I’d never really thought about it before, but of course we have 2 species of panda: the big fellas, & the much smaller red panda (Ailurus fulgens). Do they have ‘thumbs’ too?

As a post by Brian Switek shows, the answer is ‘yes; yes, they do’. And this is really interesting, as the two pandas aren’t closely related. Giant pandas are bears, while reds are more closely related to raccoons. Yet they both have modified a modified wrist bone, the radial sesamoid, that functions as a thumb and allows them to grip & manipulate bamboo – a lovely example of convergent evolution.


**The original essay, with the title The panda’s peculiar thumb’, is reproduced here.

new woo for you – ‘sound’ therapy Alison Campbell Dec 14


Over at Orac’s place, one of his commenters mentioned the therapeutic use of didgeridoos for various health issues. Surely this is a joke, I thought – but no: it seems that didgeridoo sound therapy is indeed alive and well… 

Apparently it works by a) producing ultrasound frequencies that have a massaging effect (no, really!); b) clearing "emotional and energetic stagnation"; and c) allowing "meditation and mind-body healing". And of course

[m]editation can also be used to quantum manifest healing and the co-creation of our universe.

Wow! Who’d have thunk it? Every time someone meditates, they’re fine-tuning the universe (if not actually remaking it anew).

So, we have all the signs of classic ‘woo’ here. Quite apart from the (mis)use of words like ‘quantum’ (in the words of Inigo Montoya, "you keep using that word. I do not think it means what you think it means"), we have information-poor statements like this (original grammar but I’ve emphasised a phrase):

This low frequency producing characteristic of the didgeridoo creates a no touch "sound massage" and has been reported to provide similar results as conventional ultra sound treatments and relieve a wide range of joint, muscular and skeletal related pain.

"reported"… By whom, to whom, and where? In other words, show us the data. Without that, we are simply dealing with anecdote and testimonial.

And there’s the energy cleansing: here the website blurb refers to both TCM and Ayurvedic ‘medicine’, and gushes that the effects of playing a didgeridoo are as follows:

The most basic description one could give for the energetic clearing power of the didgeridoo is "it is like a reiki or qi gong power washer." It has been reported that the energetic clearing effects are similar to traditional five-element acupuncture.

This might be fine if reiki actually did anything… And there’s that "reported" again. Plus, how was the similarity to the results of acupuncture measured, & for which ailments? (There’s quite a list of health issues for which didgeridoo therapy is supposedly useful, on that website. At least they don’t claim that it actually cures cancer…)

One testimonial, featured on the website, describes didgeridoo music as an "Ancient Vibrational medicine" (it would be interesting to know how Australian aborigines view this), which fits with the statement that 

Sound Therapy is based on the theory** that all life vibrates at various frequencies and specifically the human body has multiple vibrational frequencies that can slip "out of tune" due to emotional or energetic stagnation. When these frequencies are "out of tune" they can lead to physical and emotional health issues.

This vibration thing has been around for a while – Orac has taken several looks at the various claims made about it (including the truly bizarre claim that DNA produces sound waves, that these can be recorded, & that those recordings can be transmitted to someone else & change their DNA in turn!) However, the idea’s longevity doesn’t actually mean that it’s in any way an accurate reflection of biological reality.

And finally, we have this (emphasis in the original):

Didgeridoo Sound Therapy & Sound Healing is not an Aboriginal Australian tradition or practice, though love and respect is given to them for sharing this amazing instrument with the world.

So – not an "Ancient Vibrational medicine" at all, then… 

** Not ‘theory’ in the sense of ‘strong, scientific explanation for a large number of observations/measurements’, but rather, in the sense of ‘some idea I’ve*** come up with.’

*** Not me personally!!

melanin + the pecten … a new metabolic future?? Alison Campbell Dec 12


 While lurking over at Riddled (by doubt, insecurity and what appears to be a type of marine worm)** I was introduced to a journal article on in-flight metabolism in birds.More specifically, to the idea that melanin in the pecten – a structure in birds’ eyes that appears to function in visual acuity – is able to convert sunlight to chemical energy available for cellular metabolism. The journal is Medical Hypotheses, so I looked forward to reading about a fascinating new research-based discovery. 

 ** Warning: if you haven’t previously visited Riddled you will find that it is A Very Strange Place with an excellent sense of the ridiculous…:-)


 Or not. After all, MH is known for its lack of proper peer-review processes & its willingness to accept all sorts of ‘hypotheses’, no matter how far-out they are. (And the paper in question would certainly have benefited by some careful proof-reading prior to publication.) Anyway, this particular paper was written by Geoffrey Goodman & Dani Bercovich & bears the title "Melanin directly converts light for vertebrate metabolic use: heuristic thoughts on birds, Icarus and dark human skin." (I note with amusement that ‘heuristic’ is defined as "of or relating to a usually speculative formulation serving as a guide in the investigation of solution of a problem" by the on-line free dictionary – the first part of that definition is certainly right on the mark. I’m not quite sure, however, of the exact nature of the ‘problem’ they’ve set out to ‘solve’.)

They begin by describing the nature & apparent ubiquity of melanin in animals: it’s produced in cells called melanocytes and, while most often found in the skin & related structures, is also found deeper in the body’s tissues. As a biological pigment, melanin absorbs different wavelengths of light to a great or lesser degree; for some reason the authors comment that "[o]rigin of absorption by melanin across the full UV-visible band remains controversial", although they don’t provide a citation to support or explain this statement. Nonetheless, they go on to say that

[h]owever, the unexpected is likely from melanin, together with its clinical consequences.

To paraphrase a one-time promotional slogan for the local municipality: melanin – more than you expect!!

Goodman & Bercovich go on to note that birds have a number of specific adaptations for flight, & that flight places considerable metabolic demands on the organism. They also note that birds have a unique feature – the pecten – in their eyes and that this feature is highly melanised. And they ask, 

does this melanised organ directly convert light energy for metabolic use?

This is on the second page of the paper. Many trees could have been saved if they’d simply answered ‘no’, on the basis that a) melanocytes aren’t green & b) there’s no evidence of any photosystem-based ATP-generating pathway in these cells. However, we instead move on to stranger stuff, including the extremely shaky implication that the pecten is in some way involved in reducing the impact of hypoxia in bird embryos "at great altitudes" (citing lab experiments rather than actual research looking at embryos laid in actual high-altitude nests. I’m not sure of the record relating to high-altitude nests, but I’m willing to bet that it’s considerably less than the highest flights by adult birds… ). And – an expansion of the idea that melanin may convert light into usable metabolic energy that contributes to the energy budget in migrating birds. How?

… the pectenial melanocytes, pigment, capillaries and glial cells (if any), together with vitreous and ocular globe content and action may constitute a single photo-metabolic system; ‘compartmentalisation’ very different to that in leaf tissue.


In darker human skin, a light-initiated, melanin role in metabolism, though small/unit area, could be effective physiologically due to the large area irradiated…

Avian eyes and human skin as photosynthetic organs – you read it here first, ladies & gentlemen!***

No doubt this odd proposal will be seized upon by those espousing ‘breatharianism‘ – the bizarre belief that some people are able to subsist on air & sunlight alone, training themselves to stare at the sun for prolonged periods & thus absorb all the energy they need through their eyes. (I’ll accept that one the day someone presents evidence from a meticulous 24/7 months-long observation of such claimants, where there is no chance to nip out the back for a pie’n'coke.) In the absence of chlorophyll in their skin/eyes, all that people attempting this are likely to achieve is weight loss & dehydration (always assuming they don’t have some way to cheat), & a rapid descent into blindness.
G.Goodman & D.Bercovich (2008) Melanin directly converts light for vertebrate metabolic use: heuristic thoughts on birds, Icarus and dark human skin, Medical Hypotheses 71:190-202
*** actually that should – for a subgroup of my readers, be ‘you read it here second’, on account of the fine editors at Riddled having beaten me to it :-)

assessment for learning Alison Campbell Dec 09

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A few days back, Grant asked if I would follow up on my promise to write something on assessment. It would be great to get a discussion going around how & why we assess students, so after a bit of thought I decided to kick things off with the following post, derived from my own teaching portfolio document. (I rather feel that I need to be careful that too many of my posts don’t become Oracian in length! Not that there’s anything wrong with Orac’s posts! Quite the contrary.)

For all teachers, the $64-question is whether students are learning (and, whether they’re learning what we would wish them to learn!). Assessment is the usual tool for finding this out, although it may have unintended consequences when the nature of the assessment task shapes what and how the students learn. It took me a while to realise this – and it may be that many tertiary teachers still don’t realise this, perhaps because they are focused on teaching the content in a particular discipline rather than on the best methods for doing that.

Students tend to focus on tests and final examinations, which are forms of ‘summative’ assessment; they give the assessor an indication of where the students are at, at the end-point of a program or part thereof. The downside of this is the situation where students use techniques such as rote learning to prepare for these assessments, without necessarily taking the information on board for the long term. This is exacerbated when lecturers ask questions that simply test recall rather than in-depth understanding. Far better to ask a mix of questions, with some that can be answered through recall of facts sitting alongside those that require comprehension, understanding, and critical thinking. Students who tend to use surface-learning approaches can attempt the recall-type questions. but the ‘deep’ questions encourage and reward deep-learning strategies. This mix of questions means that it’s possible to use summative assessment techniques to encourage a ‘desired’ style of learning and thinking, particularly if you let students know in advance the type of question that they can expect.

Now, if summative assessment gives you (& the students) a snapshot of where they’re at by the end of a paper, how can you use assessment to improve their learning along the way? By using a range of formative assessment strategies to build student capability, understanding, and confidence.

Formative assessment takes many forms. The most obvious is probably written feedback on reports and essays – time-consuming to deliver, but far more useful to students than simply giving them a grade. UK educator Phil Race suggests giving feedback almost immediately and without a grade – because often the student will look at the grade and then pretty much ignore your carefully-crafted comments. Bridget & I try to do this with the essays our students write in first-year, by giving everyone some generic feedback on the issues that we know from experience will be very common. Then we don’t have to address all that individually & can focus on the specific areas with each essay that are good or in need of improvement. Having a good marking rubric – provided to the students along with the essay topics – is a big help with this. In fact, having that rubric also means (says Phil) that you can also get students to evaluate their own work. This may sound a bit counterintuitive but it’s a good way of encouraging them to reflect on the quality of what they’ve done.

Reviewing initial drafts can also help develop a range of process skills, although with a large class I doubt that teaching staff could actually look at them all! On the other hand, you can encourage students to give this sort of feedback to each other during tutorials; it’s a good learning experience for both the reporter & the reportee… Whatever way it’s done, while university assessment practices remain centred on written tests and exams, it’s really important to help students develop these skills. For example, extended essay-type answers are expected to show the writer’s understanding of key concepts and the ability to think critically about information from a range of sources. Yet science students fresh from the NCEA may not have these skills, because even ‘discuss’ questions require only relatively brief answers. So finding ways to provide meaningful formative feedback on essay assignments gives students valuable learning opportunities & also makes it more likely that they’ll develop the deep learning skills needed for real mastery of a subject.

I’ve written previously about other, in-class techniques that can provide students with immediate formative assessment on where they’re at with their understanding of a subject (here, and here, for example). Actually, the lecturer gets formative feedback too – if class responses to an item show a general lack of understanding on an issue, then that should be a pretty clear signal that I need to try a different approach :-) Over the years that I’ve been teaching I’ve increasingly incorporated some of these techniques, & one that both I & the students (judging from their comments eg “I really like the little quizzes in lectures, the conversations, and the freedom to ask questions”) find useful is in-lecture pop quizzes.

The way I use them, each quiz consists of one or a few questions that either examine students’ prior knowledge of a concept we’re going to discuss, or test their memory & understanding of concepts just covered. Students discuss their responses with each other & then I display the answers on screen & explain why I think a particular response is the correct one. (Quite often this will lead to further discussion.) There’s no pressure, no marks, but the class gets immediate feedback on where they’re at. Plus, the use of techniques like this can lead to greater student engagement and promote more active learning.

As well as encouraging students to think more deeply and critically, teaching methods like this also help them to make connections between concepts and ideas, and with their existing knowledge framework. Sometimes this can be a bit uncomfortable, when you find that existing & new information simply don’t fit together & you have to do a bit of hard analysis of your viewpoint (the ‘troublesome knowledge’ that Michael Edmonds wrote about on Sciblogs NZ). And the evidence is there that learning to link concepts in this way does have a positive outcome for our students: while for ‘recall’ questions there was no difference between students who’d learned concept mapping & those who had not, for big-picture and interpretive questions there was a statistically significant improvement in pass rates for the concept-mapping group (Buntting et al., 2005).

Of course, assessment is only part of a bigger picture. Whatever the assessment techniques you use, they have to fit within papers with a clear outline of their structure & content, so that students are aware from the start of the material they will be covering. (If you’ve read an earlier post on visualising a curriculum, you’ll know that this does come with a caveat.) They need to know how – and why – the course will be assessed. It’s also a good idea to spell out your expectations of the students, and what they can, in turn, expect from their lecturers. All these things work together to encourage students to develop an independent, deep-learning approach to their studies – & set them up for learning for life.

Next up – assessment & learning objectives…

C.Buntting, R.Coll & A.Campbell (2005) Using concept mapping to enhance conceptual understanding of diverse students in an introductory-level university biology course. Paper presented at the 36th annual conference of the Australasian Science Education Research Association.

what about genetic evidence linking us to chimpanzees Alison Campbell Dec 07


As Grant said earlier, there is a rich mine of potential posts in this particular website... This time, let’s review its author’s take on the phylogenetic relationship between Homo sapiens and Pan troglodytes.

We are indeed linked to chimpanzees — by a common Designer.

Evidence, please! One detects a rather sweeping a priori assumption here.

Even bananas have 90% the same DNA as chimps.

Er, no – the DNA correspondence is closer to 50%. Would be nice to see them get the occasional fact right. Even if the 90% figure were correct, the nature of the 10% difference would be more interesting.

Most of DNA code controls processes within the cell and are common to all living things.

Ah, those pesky facts! (Not to mention the grammar…) A considerable portion of the human genome is neither coding nor regulatory. Although one would have to concede that DNA does control/influence ‘processes within the cell’…

As all DNA is designed by the same Designer

There’s that little a priori thing again…

for the same purpose, we expect it to be similar. We agree with the evolutionist that chimps are closer to use than any other animal, but some animal has to be,

Why? If we’re assuming a series of special creation events, then why would there be degrees of relatedness at all??

and it is not surprising that over 98% of chimp DNA is the same as ours.

But take care with similarities in the design of animals. All DNA is designed by the same designer.

Can we say a priori? Yes, we can…

If the common ancestor theory was true then we would expect the same characteristics to be found coded on the same place on the same chromosome of the different animals.

Unfortunately a fair bit of our DNA can’t have been put there by that supposed designer – just look at endogenous retroviruses (ERVs), scattered throughout our genome. Not to mention the fact that both ERVs and pseudogenes common to several branches of a lineage have accumulated variation that differs from branch to branch. In other words, neither ERVs nor pseudogenes could have been part of that claimed ‘design’.

Even though our knowledge of gene mapping is in its infancy, it is already clear that this expected pattern is regularly not the case. A particular gene on one of our chromosomes may be at an entirely different place on the chimp’s chromosomes. By the way, we have 46 chromosomes and the chimps have 48. Perhaps we are more closely related to the tea tree which also has 46 chromosomes.

Yes, & we can be fairly sure what underlies the difference in chromosome number between chimp & human. Apart from Homo sapiens, all the great apes have 24 pairs of chromosomes. We have 23. The simplest explanation for the available evidence is that the human chromosome 2 originated through the fusion of two of the ape chromosomes: banding sequences match, & the remains of chimp telomere sequences are found in the middle of human chromosome 2 – right where the fusion hypothesis would predict them to be. (We can safely ignore the silly tea tree suggestion. Quite a few animal species have 2N = 46; it doesn’t tell us anything about relatedness.)

The relatively new technique of using genetic similarities to determine how long ago two species or sub-species had a common ancestor is horribly flawed. The time scale assumes a constant rate of genetic variation. But genetic variation has slowed down dramatically over the ages as natural selection processes reduce genetic potential.

Citations please. This statement suggests a woeful lack of understanding of how genetic variation is generated. Mind you, it fits with the statement elsewhere on the school’s website that organisms were created with the maximum amount of genetic variation & it’s all been downhill ever since.

Some animals, eg: the Cheetah, now have almost no genetic variation and therefore no potential to vary any more . The genetic variation which now takes place in genetically separated populations of the same species is very slow compared to what takes place, and has taken place, when genetically rich individuals adapt into new environmental niches. Therefore the time scale of technique is horribly exaggerated.

Again, citations, please! Cheetahs are known to have gone through a genetic bottleneck (maybe two) – with only a few individuals surviving that, it’s no surprise that the genetic variation remaining in the population is severely restricted. As for the next sentence – how do they know, or is this simply an example of making stuff up to suit prior conceptions of reality? They seem to have a really weird concept of what ‘genetic variation actually means…) The time scale of a ticking genetic clock based on the rate of accumulation of mutations is certainly based on some assumptions about the rate – but it’s also capable of being checked against evidence from other sources. For example, the genetic clock suggests that humans & chimps last shared a common ancestor somewhere around 5-7 million years ago – something that’s supported by the available (& increasing) fossil evidence from early hominin remains.

That reminds me, I should have a look at what they say about our own evolutionary history…

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