BioBlog

symphony of science: the world of the dinosaurs

2012-05-13T07:43:19Z

I occasionally (very occasionally, right now, with my workload the way it is) watch the Symphony of Science series on youtube. Today I took a few minutes & watched "The world of the dinosaurs", which is quite good** in a techno- sort of way.

Why am I mentioning this? Because when I was taking part in Primary Science Week, dinosaurs did get a mention. Most children seem fascinated by dinos (partly, I suspect, because they are big, dangerous, & safely extinct, as Stephen Jay Gould once remarked), and that fascination can lead them into all sorts of science-based questions. Perhaps we should make more use of dinosaurs, in primary education. (Plenty of opportunities there for building dino-science into literacy and numeracy work, after all!)

** although the pedant in me insists on noting that pterosaurs, pliosaurs, & their ilk were most definitely not dinosaurs!

musings on national primary science week

2012-05-08T10:22:55Z

As I mentioned in my last post, this week is National Primary Science Week, intended to provide science-focused professional development for primary school teachers and competitions, activities,and resources to support science teaching. I'd been asked if I'd contribute to the local program in Hamilton, & so today I trotted off to Berkeley Intermediate Normal School with a small selection of skull casts clutched in my arms (I discovered a few years back that this habit had earned me the moniker of "the Skull Lady"!). I'd been asked to run an activity on teaching about evolution: the best way to do this, to me, has always been to model it, & the hominin skulls where there to give us a bunch of talking points.

So there I was, with a room full of eager youngsters, their teachers, the bones and a whiteboard. The time flew by - in fact, we went well over time, talking for nearly 2 hours rather than the scheduled one. The students were great - attentive, courteous, curious, enthusiastic, & deep-thinking, and the questions they asked were at times really challenging. We talked about common descent; relatedness; common ancestry (& why the common ancestor of humans & chimps would look different from both); why infant chimps and humans look more similar than the adults; natural selection; mutations; human migration patterns; why carnivores have bigger brains than herbivores; how scientists actually 'do' science and why their ideas on an issue might change; what the two words in a binomial name tell us; radiometric dating; how to tell the age of an individual at death; how to tell the gender of a set of human remains; why Neanderthals became extinct... and along the way we somehow got onto anencephaly, & ethics!

I think we all enjoyed it, and everyone gained some new knowledge. Personally I found those two hours great fun, but also challenging and, well, quite tiring! I don't know that I could manage to be a primary school teacher, actually :-)

One of the key things I got out of today, actually, was a reminder of the huge enthusiasm that young students have for science. The desire for knowledge, and the thinking skills, that I saw today were truly inspiring. But that keen scientific curiosity is also something that we need to feed, and support, and encourage. Primary school teachers, in particular, need all the help they can get in this area. So next year, if you're asked to contribute to National Primary Science Week - say 'yes"! In fact, why wait until then? I rather think your local primary school might be glad to hear from you now :-)

the ero on primary school science: 'should do better'

2012-05-02T10:04:55Z

The Education Review Office's report on primary school science is all over the news today: here at Yahoo, for example. You'll find the original paper, Science in the New Zealand Curriculum: Years 5 to 8, on the ERO website. It does not fill me with joy and the following quotes from the report's Overview should show why:

Effective practice in science teaching and learning in Years 5 to 8 was evident in less than a third of the 100 schools [surveyed for the report]. The wide variability of practices between highly effective and ineffective practices was found across all school types.

And

Few principals and teachers demonstrated an understanding of how they could integrate the National Standards in reading, writing and mathematics into their science programmes. In the less effective schools principals saw science learning as a low priority. They struggled to maintain a balance between effective literacy and numeracy teaching, and providing sufficient time for teaching other curriculum areas, but particularly science.

And

Knowledge-based programmes were evident rather than interactive thinking, talking, and experimenting approaches... Student involvement in experimental work was variable.

]]> So - I was saddened by the report, & I wasn't exactly surprised either. I've written previously (here, for example) about the problems and challenges faced by primary school teachers wanting to enhance their students' understanding of & engagement with science. Back in 2010, Bull et al presented data showing that the average NZ primary school student spends 45 hours a year studying science (it was 66 hours in 2002), with only 6 other countries of those surveyed spending less time on the subject. The other worrying point was that the number of students reporting that they never did experiments increased between 1999 & 2007. At the time I commented that it could simply have been that the students didn't always recognise when they were involved in science activities, but also that at least some primary teachers might lack confidence in teaching science & so omitted it from any integrated lessons. And indeed, the 2010 ERO report cited by Bull & her colleagues found that

most primary teachers did not have a science background and that low levels of science knowledge and science teaching expertise contributed to the variation in quality of science teaching across schools... [and] that many teachers had not learned about science in their pre-service teacher training.

Nor am I surprised that schools & teachers struggle to balance the literacy & numeracy requirements of National Standards with encouraging students to a deeper understanding of science. After all, it's not that long ago since schools lost the services of school science advisers, who'd been tasked with supporting science education and teachers' professional development in this area. That loss makes it rather ironic that this latest ERO report recommends that the Ministry should look at ways to provide such support and ongoing professional development in areas including:

integrating literacy and numeracy into science teaching and learning
considering the place of National Standards for achievement in reading, writing and mathematics across all learning areas, including science
developing an approach to inquiry based learning that maintains the integrity of different learning areas, including science.

A 'back to the future' prescription, in a way. And, if we accept that science and technology and engineering and mathematics are crucial to our future, it's a prescription that needs to be met. Students who have positive, engaging experiences of those subjects at primary school might just be more likely to want to continue their engagement at higher levels. Including going on to study at university level. In light of today's statement by the Tertiary Education Minister, Stephen Joyce, that the Government intends to "rebalance tertiary education toward science, technology, engineering and maths", then all science educators (primary through tertiary) need to look at how to support teachers and students in developing that engagement.

And in that same light: next week is NZASE National Primary Science Week, set up to offer both engaging activities for primary students and free professional development opportunities for their teachers. There's a lot going on in the regions, and they're a brilliant opportunity for scientists in the universities, research institutions, and industries to help deliver the support that our colleagues in the primary schools desperately need. So, a question for my colleagues: what can you do to support this event, if not this year, then next? It could just make a difference, in your own classroom or workplace, in the future!

A.Bull, J.Gilbert, H.Barwick, R.Hipkins & R.Baker (2010) Inspired by science: a paper commissioned by the Royal Society and the Prime Minister's Chief Science Advisor New Zealand Council for Educational Research (NZCER), August 2010

Education Review Office (2012) Science in the New Zealand Curriculum: Years 5 to 8.

literate primates?

2012-04-15T02:22:22Z

A while back now, I wrote a brief piece commenting on the ability of at least some chimpanzees to recognise numbers. So it didn't come as a huge surprise to hear that members of a baboon troop could distinguish between 'real' words and random strings of letters. Yes, really.

A group of psychologists led by Jonathan Grainger (Grainger, Dufaur, Montant, ZIegler & Fagot, 2012) have just published a paper in Science entitled "Orthographic Processing in Baboons (Papio papio)", where 'orthography' is a standardised system for using a particular writing system (script) to write a particular language. The team noted that most research on visual word recognition hasn't treated words as 'visual objects', instead dealing with the relationship between information at the letter level and 'higher-level linguistic properties including semantics & syntax. But it seems that the ability to recognise words as entities resides in a part of the brain that's also involved in recognition of objects & faces, and primates are pretty good at faces, so Grainger & his colleagues decided to investigate whether baboons could extend their facial recognition skills to identifying words.

]]> More specifically:

The computation of letter identities and their relative positions is referred to as orthographic processing, and there is a large consensus today that such processing represents the first “language-specific” stage of the reading process that follows the operations involved in the control of eye movements (bringing words into the focus of central vision) and early visual processing (enabling visual feature extraction). In the present study, we examined whether the ability to efficiently process orthographic information can operate in the absence of prior linguistic knowledge.

Hence the decision to work with a non-human primate species: baboons don't use any phonological equivalents of English words (or, most likely, words in any other human language), & so can't be said to have any prior knowledge of a human linguistic system .

So, what did the researchers do? They worked with a captive social group of baboons that were living in a large enclosure with various climbing structures & sleeping areas, & set things up so that the animals also had free access to a set of test computers that used touch-screen technology & provided operant conditioning: the animals would get a food reward for correctly recognising an English word (as opposed to a string of random letters). The 'free access' thing is important - the baboons could get involved, or not, as they chose.

Using that operant conditioning, the baboons learned

to recognize four-letter English words and distinguish them from strings of letters that are not English words.

Each time a letter string (word or non-word) showed on the screen before it, a baboon could touch either a blue cross (for a random set of letters such as DRAN, LONS, TELK, or VIRT) or a green oval (for a four-letter word such as such as DONE, LAND, THEM, or VAST). A correct response was rewarded with a blank computer screen & some food (dry wheat), while an incorrect choice got a green screen for 3 seconds. They began with a single genuine word option & worked up from there (my emphasis):

Words and nonwords were presented randomly in blocks of 100 trials. The 100-trial sessions were composed of 25 presentations of a novel word to learn, 25 presentations of words randomly selected from already learned words, and 50 nonword trials. Each new word was added to the ever-increasing pool of already learned words, once responses to that word exceeded 80% correct within the preceding session. Thus, in terms of explicit information available to the baboons, a word was defined as a string of letters that was repeatedly presented, whereas a nonword was rarely repeated.

During the course of the experiment, individual animals learned to recognise a surprising number of 4-letter English words (from 81 for 'VIO' to 308 for 'DAN') - correctly distinguishing the words they recognised from a total of 7832 'non-word' combinations.

Obviously the baboons were simply making random choices at the start of the experiment, and in fact they did this in quite a biased way, with each individual tending to go repeatedly for either the green or the blue button. But - after 2000 trials, they became a lot more accurate, correctly identifying words around 75% of the time. And they were doing this on the basis of different frequencies of letter combinations, rather than 'just' memorising the real words (although that would be a rather amazing feat in itself). What's more,

words that were seen for the first time triggered significantly fewer “nonword” responses than did the nonword stimuli. This implies that the baboons had extracted knowledge about what statistical properties characterize words and nonwords and used this information to make their word versus nonword decision without having seen the specific examples before.

And:

The more similar a nonword was to a known word, the more false positive responses it produced.

The researchers noted that this mirrors responses in skilled human readers in the same situation - a rather unexpected outcome.

So, are we looking at some feature(s) of the way the primate brain is wired, that could be regarded as exaptations when it comes to processing visual symbols? Grainger & his colleagues certainly think so:

The primate brain might therefore be better prepared than previously thought to process printed words, hence facilitating the initial steps toward mastering one of the most complex of human skills: reading.

Grainger J, Dufau S, Montant M, Ziegler JC, & Fagot J (2012). Orthographic processing in baboons (Papio papio). Science (New York, N.Y.), 336 (6078), 245-8 PMID: 22499949

scientists do have a sense of humour :-)

2012-04-12T23:41:31Z

Scientists, like everyone else, have a sense of humour. (It's just that sometimes their 'in-jokes' may come across as somewhat incomprehensible.) And taxonomy seems to offer fertile ground to indulge that wit. What else can you think, when there's a tiny tiny snail with the genus name Ittibittium; a fly called Pieza kake (say it out loud); and a trilobite with the binomial name Han solo (yes, seriously!). And yes, there's more - you'll find a more extensive list here (thanks to Mark Willoughby for sending me the link). In fact, such punny names (sorry, couldn't resist it!) turn out to be surprisingly common.

It's not just the biologists; chemists seem to have enjoyed coming up with funny names for new chemical compounds. Moronic acid, anyone? You'll find a lengthy list at Molecules with Silly or Unusual Names - but you may wish to exercise a little discretion as to whether you wish to call some of the names out loud :-)

if evolution is true, why are there still apes

2012-04-11T09:40:54Z

We've just come back from a few glorious days in New Plymouth (arriving home before the change in weather). Had a great time tramping, walking the coastal walkway, eating yummy food - all those nice things you do, holidaying with friends. And as some of the party were driving from Paritutu to meet the rest of us at an outdoor cafe on the coastal walkway, they saw the following sign:

It's a variant on the old "if men evolved from monkeys, why are there still monkeys", only slightly more accurate - in the sense that we are much more closely related to apes than we are to monkeys, lol. But both versions are wrong, based on a misunderstanding on the nature of evolution, and I wonder if the sign's author would be willing to look at the evidence for the real state of affairs.

For we didn't evolve 'from' modern apes. In taxonomic terms, humans are apes: placed in the primate sub-order Anthropoidea along with gorillas, chimpanzees & bonobos, orangutans, & gibbons. Morphological & DNA evidence indicates that our nearest living relatives are the chimpanzees, with whom we last shared a common ancestor around 6 million years ago. At 4.4 million years old, Ardipithecus ramidus is the oldest known hominin - & it wasn't particularly chimp-like. Which is hardly surprising, as the ancestors of both humans and chimps/bonobos have been following separate evolutionary trajectories for all that time. As the team who discovered and described 'Ardi' have commented (White et al., 2009):

Perhaps the most critical single implication of Ar.ramidus is its reaffirmation of Darwin's appreciation: humans did not evolve from chimpanzees but rather through a series of progenitors starting from a distant common ancestor that once occupied the ancient forests of the African Miocene.

T.D.White, B.Asfaw, Y.Beyene, Y.Haile-Selassie, C.Owen Lovejoy, G.Suwa & G.WoldeGabriel (2009) Ardipithecus ramidus and the palaeobiology of early hominids. Science 326: 64 (authors' summary**) & 75-86. doi: 10.1126/science.1175802

** Teachers - the summary would be a good introductory read for your senior students.

cancer - an example of evolution at the cellular level

2012-04-10T06:12:19Z

It's more than 3 years now since a very close friend died of cancer. At the time, I wrote briefly of how cancer cell lines can evolve resistance to chemotherapy. Now Orac has written a much longer essay discussing the same thing. It's well worth reading & would probably make an excellent resource for working with senior school biology students.

Orac ends his essay with the following quote, an answer to those who ask why we have yet to cure cancer (even when using personalised therapies that in some cases target the genes themselves):

The reason we haven't cured cancer yet is because we haven't figured out how to overcome the power of evolution. Right now, cancer seems almost always to find a way. Until we figure out a way how to block all the ways it can find, personalised therapy will be effective in only a small proportion of cases.

in the lecture theatre - but definitely not giving a lecture!

2012-04-02T09:25:18Z

This is a post I first wrote for Talking Teaching - but hey! it's about teaching science!

Today's class was a real experiment for me, & although I try lots of different things in my classes, it was also a step outside my normal comfort zone. (But hey! life would be a bit boring if we always stayed safely inside that zone!) Why? Because I put into practice an idea I stole from my friend & colleague Kevin Gould (who also very kindly let me use the resources he'd developed): today was "design-a-plant" day, & probably to anyone looking into the lecture theatre during the first 30 minutes or so it would have looked as if chaos definitely ruled.

Last Friday I gave everyone an information sheet: descriptions of the features of leaf, stem & root that you might see in plants adapted to different environments. Today I trotted off to the lecture room with a box full of overhead transparency sheets, overhead pens, & printed scenarios (descriptions of a particular environment). The lecture theatre was already full – everyone had come ahead of time! This definitely wasn’t usual (it’s not that they normally trickle in late, but we're talking seriouslyearly); obviously they were expecting something special. Gulp.

]]> So I put up these slides:

then once they'd sorted out their groups I dished out pens, transparencies, scenario sheets (& copies of the info sheet for those who'd forgotten them), & away we went on a mutual journey of discovery. After all, this wasn't myidea & I had no idea how it would really work out.

Well! The class erupted into happy, productive noise. I know it was productive because while they talked, argued, explained & persuaded, I circulated, listened in, & answered the occasional question. Those with computers had them open - looking up information related to their scenario. (Next time someone asks a question that I can't answer on the spot, I'm jolly well going to get someone else to google it for me!) They drew, & altered their drawings, & drew some more. The original 20 minutes stretched towards 30, & still they were focused on what they were doing. I was almost sorry to interrupt :-)

Then, I called for volunteers. A hand went up almost immediately, & its owner came down to the overhead projector, not looking too nervous. She picked up the microphone, described her group's scenario, & showed - & explained - their response. The next speakers followed just as quickly, and each speaker received a round of applause as they finished.

But the proof's in the pudding - just what sort of plant had they designed? Well, they didn't necessarily look like plants that my botanical colleagues could have put a name to, but nonetheless, the explanations each group gave for their particular design were sound, & science-based. They'd obviously taken on board not only the info on that fact sheet, but also the material we'd been looking at in lectures & that they'd found on line. And they'd had fun doing it. (I particularly liked the Nepalese Death Vine - the eerie noise of the wind passing through its herbivore-deterring spines apparently puts the locals off harvesting it, lol - and the Serengeti "cactus" that traps water in basin-like leaves, but when there's a fire the plant's transpirative water loss is such that its tissues become flaccid and it wilts, spilling that water onto the ground where the dampness keeps the worst of the fire at bay.) Plus - so far, the feedback for this exercise on our Moodle page is all positive: students felt it definitely helped their learning about plants.

Thanks, Kevin – your design-a-plant lesson got an A+ from all of us today!

a bag moth in residence

2012-04-01T08:27:57Z

When I took the cover off the barbecue the other day, a tiny insect caught my eye. It was moving in short, fluttering hops so was fairly easy to catch, and once I had it in a jar I could have a better look. It was less than a centimetre long, dark blue with lovely contrasting golden spots on all four of its short wings. The number of wings told me it wasn't a fly (despite my husband's protestations to the contrary), as did its long antennae, which were not quite half the length of its body. And I knew 'it' was actually 'she', because there on the end of her fat little abdomen were two palest gold puffs - her scent glands.

We showed her to friends over dinner (barbecued lamb that had marinated for the day in a delightful mix of soy sauce, garlic, rosemary, lemon zest & lemon juice, with various other dishes on the side), but no-one knew what our little moth might be. And lacking a decent close-up lens on the camera, I couldn't mount a photo here for other, wiser eyes to identify.

But tonight I've just had an e-mail from our dinner guests, who identified her in a book they were browsing through in a second-hand bookstore in Thames. She's a female bag moth, Cebysa leucotelis, shown here in a photo from the Landcare Research website:

This is a strongly dimorphic species, as the male - who is capable of sustained flight, unlike his partner - looks quite different, a dull brown with pale yellow spots on his hind wings & bars of the same colour along the leading edge of each forewing.

The husband was suspicious, lest they be of the same ilk as the pantry moths currently littering the traps in my store cupboard. But no, bag moths apparently eat lichen & algae on the walls of buildings. So our enchanting little house guests can stay, without fear of further disturbance (at least until the next barbecue!).

'scientists anonymous (nz)' write again...

2012-03-26T01:20:06Z

I've written about the group who call themselves 'Scientists Anonymous (NZ)' before, in the context of determining the reliability of sources. At the time, I commented that I would have a little more confidence about the information this group was putting out there if the people involved were actually identified - as it is, they are simply asking us to accept an argument from (anonymous) authoriry. (I was rather surprised to actually receive a response to that post, albeit its authors remained anonymous.) Anyway, this popped up in my inbox the other day, and was subsequently sent to me by several colleagues in secondary schools:

TO: Faculty Head of Science / Head of Biology Department
Please find a link to the critically acclaimed resource (http://programmingoflife.com/watch-the-video) dealing with the nature of science across disciplines/strands.

Interesting to see an attempt to link it into the current NZ Science curriculum with its focus on teaching the nature of science.

PROGRAMMING OF LIFE
The reality of computer hardware and software in life
The probabilities of a self-replicating cell and a properly folded protein
Low probability and operational impossibility
The need for choice contingency of functional information
Freely share this resource with the teaching staff in your faculty/department.
Yours sincerely
Scientists Anonymous (NZ)

]]> So, I have been to the website. I intend to watch the video tonight (from a comfy chair), but the website itself raises enough concerns, so I'll look at some of them briefly here. And I'll also comment - if they really are 'doing science', then it's not going to be enough to simply produce a list of 'examples' of the supposed work of a design entity (because that's what all the computing imagery is intended to convey) & say, see, evolution's wrong. That would be an example of a false dichotomy, & not scientific at all. They also need to provide an explanation of how their version of reality might come to be.

Its blurb describes the video as follows:

Programming of Life is a 45-minute documentary created to engage our scientific community in order to encourage forward thinking. It looks into scientific theories "scientifically". It examines the heavy weight [sic] theory of origins, the chemical and biological theory of evolution, and asks the extremely difficult questions in order to reveal undirected natural process for what it is - a hindrance to true science.

The words 'undirected natural process' immediately suggest that this is a resource intended to promote a creationist world-view. I would also ask: if the documentary is created to 'engage our scientific community', then why did Scientists Anonymous send it to secondary school teachers in biology and not to universities & CRIs across the country? The blurb goes on:

This video and the book it was inspired by (Programming of Life) is about science and it is our hope that it will be evaluated based on scientific principals [sic] and not philosophical beliefs.

Unfortunate, then, that they wear their own philosophical beliefs so clearly: 'undirected natural process' as a 'hindrance to true science'.

As well as linking to the trailer for the video, & the full video itself, the Programming for Life website also presents a bunch of 'tasters'. One of these is the now rather hoary example of the bacterial flagellum (irreducible complextiy, anyone?) The website describes 'the'** flagellum thusly:

The bacterial flagellum is a motor-propeller organelle, "a microscopic rotary engine that contains parts known from human technology such as a rotor, a stator, a propellor, a u-joint and an engine yet it functions at a level of complexity that dwarfs any motor that we could produce today. Some scientists view the bacterial flagellum as one of the best known examples of an irreducibly complex system. This is a single system composed of several well-matched, interacting parts manufactured from over 40 proteins that contribute to basic function, where the removal of any one of those parts causes the entire system to fail.

** As noted on my link for this example, there is no such thing as "the" bacterial flagellum as the sole means of bacterial locomotion: different prokaryotes get around in different ways. Nor is the flagellum a case of design; its evolutionary history has been quite well explained. The lack of quote closure (& of citation) is in the original.

Mitochondria have their own executable DNA programs built in to accomplish their tasks.

Well, yes, & no. Several key mitochondrial genes are actually found in the cell's nucleus - something that allows the cell to control some aspects of mitochondrial functioning (& incidentally prevents the mitochondria from leaving!). There's a good review article here. That the number of nuclear-based mitochondrial genes differs between taxa is a good argument for evolution; for design - not so much.

Much like the firewall software on your computer the membrane contains protein gate keepers allowing only those components into the cell that belong and rejects all other components. The membrane is thinner than a spider's web and must function precisely or the cell will die.

Well, d'oh - except when it doesn't. Viruses, and poisons that interrupt cellular metabolism, get in just fine. They really are pushing the boundary with this computer metaphor.

The human eye is presented as an amazingly complex 'machine' - yet we have a good explanation for how that complexity evolved. And more telling (but omitted from this presentation): the eye's structure isn't perfect - it's a good demonstration of how evolution works with what's available,but hardly an argument for the wonders of directed design. The same can be said for the human skeleton, which is also in the taster selection, along with the nucleus, DNA, & ribosomes (which come with more, lots more, of the computer software imagery).

As I said earlier, if this video is not simply another example of the use of false dichotomy to 'disprove' a point of view with which its authors disagree, it had better provide more than metaphor. That is, I'll be looking for a strong, evidence-based, cohesive, mechanism by which these various complex features sprang into being. Otherwise, we're not really talking 'nature of science' at all.

_______________________________________________________________________________

I was going to stop there (for now) but then I noticed the 'Investigate the facts' heading. It links to a list of various papers & articles that supposedly support the 'design' hypothesis. Richard Dawkins' name caught my eye - he's there for writing that

Human DNA is like a computer program, but far, far more advanced than any software we've ever created.

I had a couple of thoughts; a) metaphor is a wonderful thing, & b) Dawkins is a biologist & science communicator, but not necessarily big on programming. (If I am inadvertently doing him a disservice, I apologise!). Someone else had the same thoughts.

tertiary teachers & accreditation

2012-03-21T10:00:54Z

This is something I wrote for Talking Teaching. It doesn't have a strong biology focus, so I hope my 'regulars' will forgive me :-). but I'd like to generate some discussion around this issue.

Over the years I've had a fair number of conversations with my students about what's involved in being a university lecturer. They ask things like how I decide what to teach, how we develop programs, and - this year - just what I do when I'm not in front of a class. (They genuinely thought that I'm 'on holiday' when the teaching semester's over: I found this rather sweet *smile*.)

And someone will always ask, do university lecturers have any training in how to teach? After all, these days primary, secondary & pre-school teachers are all required to have professional qualifications in education.

The answer is, it depends. (I'm going to talk about university lecturers here as that's the area I'm familiar with.)

]]> Back in the 'old days' (ie when I was a student, lol) you probably would have been scratching to find any university lecturer who had a teaching qualification alongside their discipline-based qualification. (Back then, Colleges of Education were generally not part of the university system here in NZ.) These days, universities have some form of professional qualification available for their staff to study for, but it's purely a voluntary decision to take it up. It's probably fair to say that a significant majority of university lecturers still do not have formal training in education.

The obvious question is, does it matter? After all, generations of lecturers have learned the necessary skills 'on the job', and generations of students have completed their degrees or diplomas & gone on to graduate.

Yes. Yes, it does matter. Let's have a look at the meaning of the term 'accreditation' (Ingarson et al, 2006):

'Accreditation', as used in this report, refers to an endorsement by an independent external agency that a professional preparation course is adequate for the purpose of a particular profession; that the course is able to produce graduates who meet standards for entry to the profession and are competent to begin practice.
..Accreditation is also an important mechanism for engaging members of a profession in decisions about standards expected of those entering their profession, as well as standards expected of preparation courses.

In the context of this post, 'accreditation' would refer to confirmation that someone had been through a program of study that adequately prepared them to teach a class. In a teaching context, that program would include exposure not just to good teaching practices, but also to the professional literature around teaching in a particular discipline. And this matters a lot, because as I've said elsewhere on Talking Teaching, there's so much more to teaching than simply transmitting information - the method which very many lecturers would have picked up, because that's how they themselves were taught. (Certainly that was my experience, back in the day, & it's one that my friend & colleague Kevin Gould described to great effect in a recent presentation on good use of teaching technology.)

In other words, university teaching is a profession (after all, I'll bet many of us put 'lecturer' on census forms & the like!), and there's a good case to be made to support academics' ongoing professional development in education and to recognise that through form of accreditation. As Hicks, Smigiel, Wilson & Luzeckyi (2010) note, such professional development can

[promote] a set of shared expectations and understandings about the nature of university learning and teaching

which would help to promote consistency in approaches across the institution and also the sector and, because staff are gaining an enhanced understanding of just how students learn, enhanced learning outcomes for students. Note that consistency =/= homogeneity! But rather, academics at the various institutions would have (Hicks et al, 2010)

some common understanding of core learning and teaching principles.

This sort of professional development, leading to accreditation, should probably be focused on new lecturers to begin with, as they're arguably those who really, really need such support. After all, as Kevin pointed out in his talk, if you're thrown in the deep end & simply emulate the practices of those who taught you, you're likely to pick up some pretty bad habits along with the good, & over time these can become deeply entrenched. (Which does suggest that it would be good, at some point, to involve experience lecturers in the conversation around best-practice in teaching and learning as well.) And you could also ask, why should both new teachers and their students struggle while the teachers find their feet? That's not good for anyone.

The other thing is, universities have changed from the days when I was a student, & they'll continue to change. Along with technological advances (which as Kevin said, have been embraced in very many secondary schools, to the point where students view teaching technology as the norm & may well expect to see it used in similar ways in university classrooms) and increasing numbers of ever more diverse students attending university (with ever more diverse experiences and needs), there's also

an expectation that universities should be more accountable to funding bodies and other stakeholders (students, parents, employers, etc.) (Hicks et al, 2010).

One way to respond to this is for institutions to be able to demonstrate that their staff have that "common understanding of core learning and teaching principles" and are able to apply these in their classrooms for the good of their students' learning.

And what's the best way to show this? Through some form of accreditation.

(Of course, for all this to happen we do need a definite change in the culture of universities. Staff are probably not that likely to want to participate in professional development if they perceive that teaching is accorded less value than research when it comes to promotion, or when they perceive that such programs are't valued by their colleagues - or when models for workload allocation don't take into account staff involvement in these programs. But there's nothing to be lost by talking about and working towards that ideal.)

M.Hicks, H.Smiegiel, G.Wilson & A.Luzeckji (2010) Preparing academics to teach in higher education. Australian Learning & Teaching Council. http://www.flindrs.edu.au/pathe/

L.Ingvarson, A.Elliott, E.Kleinhenz & P.McKenzie (2006) Teacher education accreditation: a review of national and international trends and practices. pub. Teaching Australia. ISBN 0-9775252-6-0

parasite goes bananas before s*x

2012-03-16T01:46:08Z

That got your attention, didn't it? It certainly got mine when I was scanning the Science alert news page a wee while ago. The parasite in question is Plasmodium, the single-celled organism that causes malaria. (I've written about Plasmodium before as it has a rather interesting evolutionary history.) And the research in question was published in the Journal of Cell Science - annoyingly, my institution's subscription excludes the most recent six months' worth of papers, so I could only read the Science alert release.

It's an interesting story. Like the other members of its genus, Plasmodium falciparum (which causes the most severe, potentially - & frequently - lethal form of malaria) has a complex life cycle. A mosquito that bites an infected human host will probably pick up P.falciparum in the blood it ingests, & can then transmit the pathogen to the next person it bites. Once in a new host, the malaria parasite reproduces asexually & goes through a number of life-cycle stages as it infects first cells in the host's liver & later the host's red blood cells. As the red blood cells swell with growing numbers of the parasite, they also accumulate a range of waste products produced by Plasmodium. Eventually the cells rupture & release both Plasmodium cells (all ready to infect more red blood cells) & those cells' wastes into the host's bloodstream, & this is what causes the physical symptoms of malaria.

Eventually the parasite metamorphoses into its reproductive phase - a phase that has the banana shape mentioned above. Strange though it may sound, apparently the crescent-like shape of these sexually-ready parasite cells is essential for their survival. Once outside the red blood cells the parasites are potentially exposed to the host's immune system & can be targeted for destruction, but the banana shape seems to allow at least some to escape & survive long enough to be sucked up by another mosquito. (The actual plasmodial hanky-panky occurs in the mosquito's gut.)

The Melbourne University research that's described by Science alert has found when Plasmodium's ready for s*x a particular set of proteins forms a banana-shaped scaffold underneath it's cell membane. This is interesting of itself, as it's always nice to understand the mechanism by which something happens. But it's made the research team rather excited, because identifying the proteins involves raises the prospect of targeting them - using a drug or perhaps a vaccine - & disrupting formation of the banana-shaped scaffold.

Which would pretty much put a dampener on any further prospects of hanky-panky, disrupting the parasite's life cycle & so preventing the transmission of malaria. Great stuff!

marathon man, part II (another replay)

2012-03-11T19:15:03Z

Since I (re)posted the first part of this story last week, I figure I'd better complete the tale today :-) Hopefully things will settle down a bit at work now the semester's under way, & I can get back into some 'proper' writing!

Possession of an Achilles tendon is only one of the things that sets humans up for endurance running. Bramble & Lieberman (2004) note that long-distance running requires a whole suite of adaptations for skeletal strength, stabilisation, thermoregulation, and energetics. I'll summarise some of their comments here.

]]> Skeletal strength: running places much greater stresses on the skeleton than walking does. One adaptation that reduces these stresses is an increase in the area of joint surfaces. Compared to both chimps and australopithecines, Homo skeletons have much larger joint areas in the hip joint, knee, pelvis, and lumbar vertebrae. This suggests that australopiths walked, but were not regular runners, unlike species of Homo.

Stabilisation: when someone is running, their posture is less stable than when they are walking - they tend to lean forward and the pumping action of their legs means that the torso sways from side to side. The upper body is stabilised by several features, including large spinal muscles that are anchored to the pelvis, and the very large gluteus maximus muscle. This muscle is actively involved in running, less so in walking. In addition, added stability comes from vigorously swinging the arms and thorax in opposition to the swing of legs and hips. This is made possible by a narrow, flexible waist - a feature that is fully developed in H. erectus but not the australopiths - & free-swinging shoulders.

Thermoregulation: any organism that is physically active in a hot environment will risk heat stress and must have ways of losing heat. Prolonged running places much greater demands on the body's cooling systems than walking does.

In modern humans, sweat glands permit evaporative cooling, and the reduction in body hair means that heat is more efficiently removed through convection. Obviously these don't fossilise & so we can't be certain of when they evolved. However, other features are also important in thermoregulation. One is the body's surface area relative to body mass - it is greater in tall, thin bodies (eg erectus, but not Australopithecus). Another is mouth breathing. This allows higher rates of airflow with less muscular effort than nose breathing, and also functions in shedding body heat. Modern runners are mouth breathers; the great apes are not.

Energy costs & demands: as you'll remember from the previous post, the Achilles tendon contributes to the energy efficiency of running by acting as a spring, reducing the metabolic demands on muscles. Skeletal evidence from australopith leg bones suggests that these hominins lacked an Achilles tendon and so are less likely to have been good distance runners. The arch of a human foot also acts as a spring, again contributing to energy efficiency.

Stride length is also important. Running humans increase speed by increasing the length of their stride, something which is related to the presence of 'springs' in the legs & also to having relatively long legs. Homo erectus definitely had long legs, relative to body mass - perhaps 50% longer than in Australopithecus afarensis. Longer legs do impose an energy cost, however, as they are swung to & fro. This can be reduced by having most of the leg's mass closer to the hip than the ankle (eg through reduction in the size of the foot).

Overall, it's reasonable to hypothesise that endurance running is a feature that evolved with the genus Homo, and probably in erectus. However, we need more information in order to test that hypothesis eg foot remains from erectus & more post-cranial material from habilis.

Reference: D.M. Bramble & D.E.. Lieberman (2004) Endurance running and the evolution of Homo. Nature 432: 345-352

marathon man (rpt)

2012-03-08T08:04:15Z

I've been blogging since August 2007. Which seems quite a long time, looking back on it :-) Anyway, because I'm kind of rushed at the moment - & on the theory that new(ish) readers might not have delved all that far into the back issues, I thought I'd repost a couple of pieces from way back then, just to keep you going.

I was looking through the SciTech Daily website (a good place to go for new reading in a whole range of science areas) when I saw the link to an article on the evolution of running in Homo. Followed it, read the article - & thought, this is really interesting.

The article describes research on the efficiency of walking and running in humans. It notes that the Achilles tendon linking calf muscles to the heel is essential for energy-efficient running. Chimps and gorillas don't have this long tendon, and the research team comment that it would be very interesting to know at what point in our evolutionary history the Achilles tendon evolved:

]]>

But if, as seems likely, early humans lacked an Achilles tendon then whilst their ability to walk would be largely unaffected our work suggests running effectiveness would be greatly reduced, with top speeds halved and energy costs more than doubled.

Efficient running would have been essential to allow our ancestors to move from a largely herbivorous diet to the much more familiar hunting activities associated with later humans. What we need to discover now is when in our evolution did we develop an Achilles tendon as knowing this will help unravel the mystery of our origins.

No Achilles tendon in great apes? Another search took me to a blog entry by PZ [sadly the link in the original post no longer takes you to his "Marathon Man" post], which included this image of human & chimp leg anatomy (the original is from a paper in Nature). You'll see that in humans, the Achilles tendon links the calf muscle to the tarsal bone in our heel. But in chimps, the muscle extends right down to the tarsal. Why is this difference significant? To find out, I read the Nature article (reference at the end of this post).

In humans, the Achilles tendon acts as a shock absorber and also stores energy. It stretches as your foot comes down (the braking phase), gaining elastic potential energy. Then, it releases that energy through recoil as you push off from the ground again. That is, the tendon is acting like a spring - one that can save up to 50% of the metabolic cost of running through reducing the work done by the muscles themselves. This makes Homo quite good at endurance running, something that would be essential for active hunting out on the savannah.

It's not just the Achilles tendon, of course. There's a whole suite of adaptations that may be related to running as a means of getting around. The question is, did these adaptations arise during the evolution of bipedal walking, or are they specifically related to running? I'll summarise that discussion in the next post.

Reference: D.M. Bramble & D.E. Lieberman (2004) Endurance running and the evolution of Homo. Nature 432: 345-352

changing teaching techniques

2012-03-05T08:41:06Z

This post’s title is another one drawn from the search terms that brought people to my 'other' blog at Talking Teaching :-)

I’ve written quite a lot about the benefits students may gain as a result of lecturers changing the techniques they use in the classroom. A while back I wrote about the idea of helping students to visualise a paper’s curriculum, & this semester I decided to try that out with my first-year biology class. Today was the first day of the new semester, & I thought I’d share what I did with them – it would be interesting to hear what others think of this approach, so please do add a comment :-)

]]> I kicked off with this slide – I thought the images captured some of the confusion that many first-year students seem to share as they enter their first year of uni study. It’s a fair bet that all the new terms & concepts thrown at them in many ‘traditional’ paper outlines don’t help :-)

Then I listed the obvious: the various classroom ‘styles’ they’ll be experiencing (ie lectures, labs & tuts). And pointed out that there are definite bi-directional links between them – this is because (in my experience, anyway) some students tend to see them as isolated enitities. When I first tried my hand at a diagram like this my wonderful friend & colleague Brydget pointed out that it was way too complicated; the kids would just get lost in the detail. I took her advice & had another go :-)

And then I asked, OK, when you enrolled in this paper, what did you think you’d be doing & learning? This was the very first class so I wasn’t sure what responses I’d get, if any, but I wanted to send the message from the start that this is how I teach & that active participation is the norm in my lectures. But people put their hands up. ‘Content,’ they said; ‘stuff about plants & animals & how they function & how they interact with their environment.’ ‘Great!’ I said, ‘and I need to make sure that we do look at some of this, because my colleagues further down the line will expect you to be familiar with this material.’

‘But wait!’ I said, ‘there’s more!’ (Because beyond ‘dissections!!!’ no-one had mentioned any process skills.)

So now we could look at those other skills & why they are relevant. We’d talked a bit about plagiarism at orientation last week, so I could check back on their understandings around this – & emphasise that we’ll be working with them to develop their skills in academic writing, referencing, citations & so on. And critical thinking – to me, this is surely one of the most important skills that any student could acquire during their time at university.

Now, where are we going with all this?

Well, there’s the obvious one – that first-year is expected to turn out students with the knowledge & skills that they’ll require if they’re going on to further study in the subject. But there’s a second, equally important point here, and it hinges on the fact that there are quite a few students in the class who aren’t going to major in biology, & who may not actually be science students at all – they’re taking the paper as an elective in another degree altogether. What do I hope they will gain from it?

Yes – apart from (I hope!) helping them gain an enthusiasm for & appreciation of the living world, I really really want to enhance the scientific literacy of all my students, so that they can apply this understanding in their own future lives, regardless of whether they’re going on to a career in the sciences.

Now, I don’t know what the class thought of this approach – yet. I’ve asked them to let me know (anonymously if they like) through our Moodle page. But it would be good to hear from readers as well :-)