SciBlogs

Posts Tagged books

rapid evolution in cane toads Alison Campbell Oct 27

No Comments

In her book Paleofantasy, Marlene Zuk discusses cane toads (Bufo marinus) as an example of just how rapidly evolutionary processes can work. These amphibian pests were introduced into Australia in 1935 to control borer beetles in sugar cane. Unfortunately the toads never got the memo about this expectation, and have spread rapidly across the continent, damaging a range of native ecosystems as they go. (They’re aided by the fact that they’re toxic, killing many of the predatory animals that might otherwise eat them.)

And it’s not just that the toads are and always have been fast hoppers. As this article says

When the toads were first introduced, they spread at a rate of about six miles (ten kilometers) per year. Today cane toads advance more than 31 miles (50 kilometers) annually.

In other words, they’re getting faster, with animals at the ‘invasion front’ moving up to 1.8km in a night. (The researchers were able to measure the toads’ speed by fitting them with miniature radiotransmitters, strapped to their waists.) Phillips & his colleagues (2006) point out that speed of movement in toads is correlated with leg length, and asked the question: is there a difference in average leg length between toads at the front of the amphibian wave spreading across Australia, and those at the back of the bunch? The answer:

As the toad invasion front passed our study site, we measured relative leg lengths of all toads encountered over a 10-month period. Longer-legged toads were the first to pass through, followed by shorter-legged conspecifics (order of arrival versus relative leg length: r = -0.34, n =552, P = 0.0001). Longer-legged toads therefore moved faster through the landscape.

And the evolutionary changes don’t stop there. In a paper just out, Brown, Phillips & Shine (2014) describe how the animals’ tendency to travel in a straight line has changed too:

Radio-tracking of field-collected toads at a single site showed that path straightness steadily decreased over the first 10 years post-invasion.

The research team found that this behavioural change had a genetic underpinning. The progeny of toads from the invasion front moved in straighter paths than the offspring of toads from older, well-established populations to the east. In addition, “offspring exhibited similar path straightness to their parents.” Brown & his colleagues concluded that

The dramatic acceleration of the cane toad invasion through tropical Australia has been driven, in part, by the evolution of a behavioural tendency towards dispersing in a straight line.

G.P.Brown, B.L.Phillips & R.Shine (2014) The straight and narrow path: the evolution of straight-line dispersal at a cane toad invasion front. Proc.R.Soc. B 281(1795) doi: 10.1098/rsph.2014.1385

B.L.Phillips, G.P.Brown, J.K.Webb & R.Shine (2006) Invasion and the evolution of speed in toads. Nature 439: 803. doi: 10.1038/439803a

Teachers: there’s an open-access summary of the 2006 paper here.

‘paleo’ diet? or paleofantasy? Alison Campbell Oct 17

No Comments

The ‘paleo’ diet story on Campbell Live tonight spurred me to finish my review of one of the most entertaining popular books on genetics that I have read for some time. Entertaining, and informative, in equal measure. I wonder what author Marlene Zuk would have made of the TV story.

book cover Marlene Zuk (2013) Paleofantasy: what evolution really tells us about sex,diet, and how we live.  Norton (New York)

ISBN 978-0-393-34792-0 (paperback)

For in that story we heard gems like this: “It’s a commitment to eating food that is unadulterated, eating food in its most natural state.” Paleo proponents (says the TV story) believe our most natural diet is that of our Palaeolithic cavemen ancestors. Somehow I doubt our ‘cavemen’ ancestors were eating avocados, beetroot, bacon or kale. (There’s also an air of chemophobia, with one proponent of paleo eating stating that their diet contains “[n]othing nasty and nothing you can’t pronounce” – which reminded me of the series of posters by Australian teacher James Kennedy, showing the list of chemical compounds found in natural food items: blueberries, anyone?).

Proponents of the so-called paleo diet seem to think that humans haven’t evolved in the last 10,000 years (since the advent of agriculture), and that this means that our bodies aren’t ‘designed’ to cope with the products of the agricultural revolution. (This, while eating foods that bear little resemblance to their Palaeolithic counterparts. Look at teosinte, the ancestor of maize, for example: small, stone-hard kernels arranged in a few lines on a stalk. Nothing like the fat, soft, juicy kernels on a modern cob of corn.)

As Zuk notes, the paleofantasy happily assumes that at some point in the past (around 10,000 to 40,000 years ago, depending on who you’re listening to), humans were perfectly adapted to their environment, including their diet. But, she asks, why hark back to that particular point in time?

would our cave-dwelling forebears have felt nostalga for the days before they were bipedal, when life was good and the trees were a comfort zone?

Plus, of course, there’s the question of just which ’cavemen’ we’re aspiring to be like. We’ve no guarantee that the life-styles of modern hunter-gatherer populations are a good approximation of life 40,000 years ago. Should we be Inuit, or Kung?

And there’s no reason for us to have stopped adapting to evolutionary pressures once agriculture became the mainstay of human populations – in fact, there’s a great deal of evidence to the contrary, some of which I’ve written about previously -the evolution of lactase tolerance, for example. Similarly, with the spread of arable farming, those with the ability to digest grains would be at an advantage, to the extent that there is a higher number of copies of the gene coding for salivary amylase in populations with a long history of eating starchy grains, compared to populations where the diet has traditionally been low in starches. And Zuk provides many examples of just how rapid evolutionary change can be, in humans and in other animals (changes in cane toad morphology, in the short span of time since their arrival in Australia, are a particularly elegant case in point). The final chapter, which gives considerable detail in answering the question, are we still evolving, would be very useful to biology teachers during human evolution classes.

In other words,

[t]he notion that humans got to a point in evolutionary history when their bodies were somehow in sync with the environment, and that some time later we went astray from those roots – whether because of the advent of agriculture, the invention of the bow and arrow, or the availability of the hamburger – reflects a misunderstanding of evolution.

As the extended title of her book points out, Zuk feels that the paleofantasy extends well beyond the current diet fad. It influences beliefs about health and illness, about family life, about sex. (This last is the focus of all sorts of wistful imaginings: the book provides an entertaining sample of these.) Do bonobos, for example, really provide a good model for how human sexual activity might have been before modern mores took over? I can’t see it myself: humans and their chimpanzee cousins have follwowed separate evolutionary trajectories for 5-6 million years, and there’s no good reason why either species should closely resemble the last common ancestor. And that goes for aspects of intimate morphology as much as for behaviour: I did not know that chimpanzees have penis spines –  ”hardened growths that may serve to sweep away the sperm of previous mates.”

Zuk concludes that the paleofantasy is just that, a fairy tale – and one that limits our understanding of our own biology and evolutionary history:

But to assume that we evolved until we reached a particular point and now are unlikely to change for the rest of history, or to view ourselves as relics hampered by a self-inflicted mismatch between our environment and our genes, is to miss out on some of the most exciting new developments in evolutionary biology.

 

Anyone interested in hearing Professor Zuk speak should check out the details of her upcoming lecture tour. I’ll be grabbing a ticket to the Hamilton event!

 

helicobacter pylori and the complexity of the human microbiome Alison Campbell Jul 24

No Comments

In their first-year microbiology lectures. our students hear about Helicobacter pylori, the bacterium associated with the development of gastric ulcers (a discovery that eventually saw Barry Marshall and Robin Warren receive the 2005 Nobel Prize for Physology or Medicine). The trouble is, I suspect that this is all that they hear about a story that is considerably more complex.

The story of H.pylori is just one part of Jessica Snyder Sach’s highly readable and thoroughly-referenced book, Good Germs, Bad Germs, which introduces the reader to the complexities of the human microbiome: the intricate microbial ecosystems found on and within the human body.

Good Germs, Bad Germs: health and survival in a bacterial world. Jessica Snyder Sachs (2008) pub. Hill & Wang. ISBN (e-book): 0809016427

The book begins with the harrowing tale of a young man’s death from a rampant MRSA infection, and of a child living with multiple life-threatening allergies.- two tales linked by the unforseen effects of our overuse of anitbiotics and our fixation on hygiene. (Actually, the former was not entirely unseen: in his 1945 Nobel Prize lecture, Alexander Fleming commented on the possibility that overuse of penicillin could see the development of resistant bacteria. Unfortunately, at the time this warning went unheeded – if indeed it was really heard – for example, penicillin was available as an over-the-counter drug in the US for almost a decade after its introduction in the 1950s, which would undoubtedly have contributed to the development of resistant strains of microbes.)

Then, after an introduction to the “war on germs” and scientists’ search for the ‘magic bullets’ that would (it was hoped) allow us to vanquish them forever, it’s on to “life on man”. Wherein I learned heaps, including the thought-provoking suggestion that there may be some adaptive significance to the fact that babies usually exit the vagina with their heads face backwards, towards the mother’s anus. For babies guts are colonised by bacteria very soon after birth – & they may receive an inoculum of faecal matter on the way out, to join the lactobacilli  from the vagina itself and bifiobacteria from breast milk.

Incidentally, while all this may sound uncomfortably germy, there’s good evidence that the gut microflora are essential for survival. Lab animals reared in absolutely germ-free conditions, & whose guts never develop a microbial flora, fail to thrive. What’s more, Snyder Sachs  comments that the combined acction of several species of intestinal bacteria “liberate as much as 30 percent of the calories a person absorbs from food, especially from high carbohydrate meals.”

Reading on – and it was really hard to put this book down! – you’ll hear about the hygiene hypothesis, which suggests that many of the inflammatory diseases that plague us today are an unforeseen result of lives that are too clean. Along with this is the ‘dirt vaccine’: the idea that vaccination with a mycoplasma may help to redirect the overzealous immune response underlying many allergies. Then it’s on to a deeper look at the development of antibiotic resistance and the rise of the superbugs, which has been exacerbated by the widespread use of antibiotics in farm animals. (Encouragingly, Snyder Sachs notes that banning this use, as in the Netherlands, can lead to a reduction in ‘superbug’ prevalence.) And finally, we look at our options for the future, and whether we can find a way to live in balance with our burgeoning microbial ecosystems.

And H.pylori? It turns out that this particular bacterium has been with us for at least 60,000 years, something that’s been used to track human migration patterns that began when Homo sapiens first left Africa. H.pylori colonises the stomach in the first few months of life, before gastric acid secretion really ramps up, and can actually affect that acid secretion, lowering the pH enough that Helicobacter can survive but most other species are killed. There is a plus to this: the lowered pH reduces the effects of acid reflux & the development of oesophageal cancer. But then, there’s those gastric ulcers – which apparently didn’t really become an issue until the 1830s, when this was mainly a disease of the upper classes, possibly linked to a decline in colonisation related to improved sanitation and the use of early antibiotic products. And gastric ulcers

remain virtually unknown in undeveloped regions of the world such as Africa, where most people become colonised in infancy. It may be that delaying or disrupting H.pylori colonisation with water sanitation or antibiotics has somehow altered the immunological ‘truce’ that this microbe forged with our immune systems over thousands, possibly millions, of years.

I like the full, more complex story; it’s so much more satisfying than the ‘helicobacter – bad’ version, and it’s a much better reflection of the dynamic relationship between humans and the microbes that call us home.

just like ‘alien’ – moray eels have *two* sets of jaws Alison Campbell Dec 19

No Comments

Around 14 months ago the husband & I were spending a lazy holiday in Rarotonga. We did quite a bit of snorkelling on the reefs, and especially enjoyed our experiences at Muri, where we saw a good range of reef fish in near-ideal conditions (as in, clear, calm, relatively shallow water). There were several moray eels, which were at first hard to spot – and then you saw them, loitering in a crevice, giving the impression of watching you rather closely and with their open mouths exposing some rather sharp, pointy teeth: “all the better to bite you with, my dears.” We viewed them with caution.

But when you think about it, that wide-mouthed loitering would seem to pose a problem for the eels. This is because most predatory fish feed by opening their mouths wide from a closed position: water floods into the lower-pressure area inside the mouth & dinner comes along for the ride. Sitting around with your mouth half-open doesn’t sound like a good strategy. I found the answer while reading The Book of Barely Imagined Beings by Caspar Henderson, under – you’ve guessed it – ‘E for Eel’. (This wonderful book was recently reviewed on Sciblogs by Siouxsie Wiles.)

 

As an aside, I love the way this chapter kicks off:

The Snowflake1 eel, a kind of moray, is harmless if you leave it alone and refrain from drinking its blood (which is toxic).

I was also fascinated to know that the morays’ genus, Echidna, derives from a rather unpleasant individual in Greek mythology; beside her, Henderson says, “the Snowflake and other Moray eels are pussycats” – yet people still fear them:

Part of the reason for this is surely their superficial resemblance to snakes… Another may be the eels’ mouths, which are constantly open, suggesting that they are ready to strike. But this is not, I think, the whole story. An eel’s eyes, bulging and unblinking, look like those of a corpse, and the way the animal moves its body … is disturbingly sensual. Saltwater eels are uncanny.

You can see, I hope, why I like the book; the writing is lovely. But anyway, back to those gaping maws.

Henderson explains how a moray’s hunting style more closely resembles the eponymous ‘Alien’, for these eels have two sets of jaws! The second set is found in the back of the throat – the ‘pharyngeal jaws’ -  but can be thrust forward extremely quickly and retracted equally rapidly, so that they “[pull] the prey down into the oesophagus as the animal closes its mouth.” You can see how this all works in the image below, from the National Science Foundation website.

Image credit: Zina Deretsky, National Science Foundation (after Rita Mehta, UC Davis)

The work of Rita Mehta, who’s been studying moray eels’ feeding anatomy, is featured in the following video, in which you can see those pharyngeal jaws move forward to grasp a ‘prey’ item. All the more reason to be fairly circumspect on the reef, methinks!

1 If you think ‘Snowflake’ is an unusual name for an eel, how about the ‘Rusty spaghetti’ version?

essays on our fascination with those who are different Alison Campbell Oct 08

No Comments

Book Review: The Two-Headed Boy and Other Medical Marvels 

by Jan Bondeson

Cornell University Press, USA (2004)

Paperback: i-xxii, 297 pages

ISBN: 0-8014-8958-X

RRP: US419.95

It's all Grant's doing, really. If he hadn't picked up on an off-hand comment of mine (relating to vipers in bosoms) & turned that into a catchy blog post, I quite probably wouldn't have gone looking for other books by Jan Bondeson, or found The Two-Headed Boy and Other Medical Marvels

This is a fascinating, saddening, and occasionally appalling book by a humane and extremely well-read author. The subjects of Bondeson's essays are those who are (or were, for these are historical essays) in someway very very different from the rest of us: the exceptionally tall, the enormously obese, the unnaturally hairy, the two-headed boys of the title. Those who in what we'd like to regard as a less-enlightened age would have spent their lives in what were then called 'freak' shows, for others to gawk and gape at. (Not that this horrified fascination with those who are different has disappeared. We just don't deem it appropriate to pay to indulge it.) And while the money may have poured in from the gawkers, all too often most of it made its ways into the pockets of 'managers', and not the afflicted individuals. (Although there were exceptions, which we'll come to shortly.)

One of the things I particularly enjoyed about the book was its interweaving of scientific and historical perspectives. Did Countess Margaret of Henneberg really have 364 – or was it 365 – children all at once? Today we'd immediately say, well of course not! But then, what are the origins of the tale described in Bondeson's essay, "The strangest miracle in the world"? The author examines the development of the legend over the years, noting with wry amusement that until quite recently childless women would wash their hands in the bowl in which the unlikely children were supposedly baptised – even though the original was destroyed long ago. And he shows how science has a part to play in the explanation: it's possible that the Countess delivered a hydatidiform mole. Although you'd think that the midwives might have had some experience of this condition, the mass of small blobby bits might have been seen by them as a large number of gravely undersized babies.

At least Countess Margaret wasn't displayed for money (although the local townsfolk must subsequently have made quite a lot out of tourists), but money's involved in most of the stories. (And attention, which may well have been the driver for the poor lady who pretended to lay eggs – a tale which also attests to the extreme gullibility of those in attendance at the delivery!) Both Daniel Lambert (for a time the fattest-known human, although more recently he has been outweighed by a man nearly double Lambert's 700+ pounds) and the 'Swedish Giant', Daniel Cajanus, parlayed their physical extremes into quite comfortable livings, for not only were they charming and intelligent men but they also had the sense to manage their own affairs. All too often that hasn't been the case, with children put on display out of desperation or greed on the part of parents or 'managers'.

Of those children, I sometimes wonder if our most awful fascincation might not rest on conjoined twins. Bondeson discusses several examples, including parasitic twins and two-headed children. Apparently dicephalus (two-headed) twins represent around 11% of conjoined twins, the great majority of whom die before or soon after birth; certainly a google search will produce more images than you may be comfortable with. I first heard of them when reading Stephen Jay Gould's essay on the twins Ritta-Christina, in which he not only discussed the children's short, sad lives but also the issue of what constitutes an individual. Bondeson also tells their story, but the two-headed boys of his title had a better time of it; in fact, he describes Giovanni and Giacomo Tocci as the "most celebrated pair of dicephalus conjoined twins of all times". While most dicephalus twins are short-lived, often due to other structural abnormalities in one twin or the other, the Tocci brothers were born in 1877 and lived at least into the second decade of the 20th century, at least in part because the boys were 'symmetrical' in that both seemed to have properly-developed hearts and lungs. Like all the dicephalus twins described in the book, the Toccis were two distinct individuals with different personalities and intellects.

And this, of course, poses some serious ethical questions. While it is possible to separate some conjoined twins, depending on the degree to which they share organs and blood vessels, to do this for dicephalus twins means that either both would spend the rest of their lives incapable of independent movement & with significant post-surgical disfigurement, or one would be sacrificed that the other might live. To whom should this decision fall? (The parents of perhaps the most famous living dicephalus twins, Abigail & Brittany Hensel, never considered this option, & their daughters are now young adults.) 

Yes, this is a fascinating and thought-provoking book, not least because it offers a discomforting mirror in which to review how we see those who are so different from ourselves.

 

goat glands, greed, and gullibility Alison Campbell Sep 30

No Comments

Book Review: Charlatan: America's Most Dangerous Huckster, the Man Who Pursued Him, and the Age of Flimflam, by Pope Brock 

Price: US$14.95
Paperback: 
324 pages
Publisher:
 Three Rivers Press, New York, USA (2008)
Language:
 English

ISBN: 978-0-307-33989-8
                                                                  

Goat glands, greed, and the gullibility of others turned out to be a winning combination for John R. Brinkley. In the early years of the 20th century it seemed as if science could do anything, perhaps even extend life – including life in the bedroom - well beyond the allotted three-score years and ten. Brinkley saw a market there, and managed to parlay the testicles of young goats, combined with the gullibility of the vain, the impotent, and the just plain desperate into an enormous personal fortune.

Pope Brock's biography of Brinkley, Charlatan, is both entertaining & alarming in equal measure. Entertaining, because it's quite a rollicking read. Alarming, because it highlights how easy it is for someone with a persuasive manner and a feel for the market to hoodwink an awful lot of people, and get rich doing it. For despite the fact that Brinkley had no real medical training, he somehow manage to persuade large numbers of men to part with good money (hard to come by, in the Depression years) for the dubious privilege of having the gonads of young billy goats implanted into their own scrotums. (These days, I guess people buy cialis & horny goatweed on-line instead.) We're not told what subsequently happened to the goats.

Now, the mind boggles at the sequelae of this, given the way your immune system would likely reject the goat gonads, & the likelihood of the transplants decaying anyway since they'd have had no blood supply. But nonetheless, Brinkley prospered & somehow people never seemed to hear of the folks for whom things went very, very pear-shaped. Nor was he alone in his endeavours: other quacks offered chimp glands, vasectomies, & various 'electric' treatments – for rejuvenation, as well as the more personal problems in the bedroom, but somehow it was Brinkley who rose to the top, eventually even travelling to Japan to market his techniques.

Brinkley fairly quickly set up shop in a purpose-built hospital in Milford, Kansas. You'd think that staying in one place for too long would not be a sensible move for a charlatan, but Brinkley prospered there – to the extent that he even ran for governor. Perhaps he was bringing so much money, & business, into the town that people turned a blind eye to his failures. Brock describes how Brinkley built his own not-so-small empire in Milford. Having recognised the power of advertising, the good doctor expanded into mail-order nostrums for pretty much anything that ailed you, and then into the brave new world of the airwaves. When the regulators finally removed his medical licence, he simply left a couple of locums to do the operations and threw himself into expanding his radio operations, eventually broadcasting from a massive station just over the border with Mexico (to get around the US ruling that radio stations could use only 5000 watts: Brinkley deafened the southern states with his 500,000 W transmitter). In the process, Brock tells us, he even kickstarted America's love affair with country-&-western music.

There was, of course, an eventual reckoning. Into Brinkley's story, Pope weaves the tale of the various medical investigators who tried to shut him down; most notably, Morris Fishbein, eventually the editor of the Journal of the American Medical Association. It took years, but finally, in 1939, Brinkley had his day in court, and lost. Once found guilty of medical malpractice, he was sued by many individuals & the IRS chased him for back taxes. His radio station closed, & he died in 1942.

But why did Brinkley have such a long run? You'd think, with a 'treatment' that was worthless, reality would have caught up with him much earlier. In explanation, Brock provides the following quote from Samuel Johnson, which probably goes a long way to explain why charlatans like Brinkley have never really left us:

[W]e go with expectation and desire of being pleased; we meet others who are brought by the same motives; no one will be the firest to own the disappointment; one face refelects the smile of another, till each believes the rest delighted, and endeavours to catch and transmit the circulating rapture. In time, all are deceived by the cheat to which all contribute. The fiction of happiness is propagated by every tongue, and confirmed by every look, till at last all profess the joy which they do not feel, [and] consent to yield to that general delusion.

the drunken botanist Alison Campbell Aug 07

No Comments

That’s the title of one of the books I’m reading at the moment: The Drunken Botanist, by Amy Stewart. (I do not know any drunken botanists!) Contrary to any expectations engendered by the title, the book is a thoroughly engaging wander through botany, history, & a little bar-tending (although, now that I look at the recipes, there are quite a few of them!) – in the sense that it includes recipes for a range of cocktails where at least some of the ingredients are derived from plants.

But be warned. As the author points out, just because many of these ingredients come from plants, doesn’t mean you can just set to it & start brewing up a storm. She notes

Do remember that plants employ powerful chemicals as defenses against the very thing you want to do to them, which is to pluck them from the ground and devour them…

It is also important to note that distillers can use sophisticated equipment to extract flavourings from a plant and leave the more harmful molecules behind, but an amateur soaking a handful of leaves in vodka has no such control… Just because a distiller can work with them safely doesn’t mean you can, too.

Which is why those consuming ‘moonshine’ may well be at risk of more than a simple hangover.

Anyway, I am finding this book to be a fascinating ramble down a whole range of information by-ways. I’ve learned, for example, that the agave – whence come tequila & mezcal – is actually related to asparagus, & that it’s possible to persuade the plant to produce up to 250 gallons (more than 1000 litres) of sap over a period of several months, by cutting and wounding the flower stalk just as it begins to grow. (In this, an agave plant outstrips the annual production of a sugar maple tree – but the tree has the advantage that it lives to flow another year. The agave eventually dies, exhausted.) This liquid is fermented very quickly by ‘wild’ microbes, & – being an innocent in these things – I thought that would be distilled to produce tequila. But I was wrong – this spirit’s produced from a base of roasted agave hearts. And while you might be thinking of a metal or glass still, it seems in Mexico they used to use a hollow tree trunk as the basis of the still!

Apparently the worm is there as a marketing ploy…

So, there’s snippets of genetics, & palaeontology, & chemistry, & botany, & anthropology – it really is an interesting book. And Stewart has the ability to turn some lovely phrases. I’ll leave you with the following, which I love & will be using tomorrow when discussing cellular respiration in class:

The science of fermentation is wonderfully simple. Yeasts eat sugar. They leave behind two waste products, ethyl alcohol and carbon dioxide. If we were being honest, we would admit that what a liquor store sells is, chemically speaking, little more than the litter boxes of millions of domesticated yeast organisms, wrapped up in pretty bottles with fancy price tags.

A.Stewart (2012) The Drunken Botanist: the plants that create the world’s great drinks. Algonquin Books of Chapel Hill. ISBN 978-1-61620-046-6

"the aviator" – a vision of the future that’s a little too close for comfort Alison Campbell Jan 09

No Comments

I found the Herald’s front page this morning a sad and depressing read. My heart goes out to all those affected in some way by the terrible bush fires ravaging so much of Tasmania, Victoria, & New South Wales.

I also had a certain sense of deja vu as I read of the fires – for I’d read something similar last year, in blog-buddy Gareth’s book The Aviator, Book One of the Burning World series. Except that in the book, the scale of events is much greater than is (thankfully) the case at the moment, and Melbourne is destroyed by a fire storm. Gareth’s vision of a not-too-distant future in which our global ecosystems have been irreparably affected by anthropogenic greenhouse warming, is both an alarming foretaste of how things could become**, and a rather good read (another blogging friend, Ken Perrott, reviewed the book very favourably when it first came out, & I’ve been meaning to write my own review for quite a while). The story follows the key character (& narrator – well, one of them), an airship pilot called Lemmy, in his travels around a world in which ecosystems and societies have collapsed, or changed – in many instances, beyond recognition. (There are actually 2 narrators: the second is Jenny, the artificial intelligence who actually runs the airship. Their commentaries alternate, & it’s interesting to see the differences in perspective, especially given that the AI is to some degree self-aware.)

As the series title suggests, in this future world it’s not only Australia that suffers from fire. Lemmy also witnesses huge fires in the Arctic, where massive methane deposits originally locked under the ocean in the form of methane clathrates have been ignited and the flames burn seemingly endlessly. I’ve recently read more about these deposits in Bill McGuire’s Waking the Giant: we are talking significant carbon stores here, at around 2000 billion tonnes of carbon trapped in the form of clathrates: something that is highly attractive to energy companies & of deep concern to climate scientists.

The first time I read The Aviator, I thought it would be a rather good classroom resource for senior students. And that hasn’t changed on a subsequent re-reading. Its engaging focus on a current, extremely relevant topic means that the book could be used in many different areas as the basis of discussion and to provoke further student research: how do individuals, and societies, cope with change? What happens when the technologies we rely on so heavily are no longer available, or are concentrated in the hands of relatively few people? How would a rise in average global temperature affect various ecosystems? Is a future such as the one Gareth describes, something that we can yet avoid?

Highly recommended.

 

Gareth Renowden (2012) The Aviator (The Burning World). Limestone Hills Ltd.

Bill McGuire (2012) Waking the Giant: how a changing climate triggers earthquakes, tsunamis, and volcanoes. Oxford University Press. ISBN 978-0-19-959226-5

 

** In some ways it reminds me of Richard Cowper’s The Twilight of Briareus - though having said that, Cowper’s world has been sunk into an ice age, and his story has a strong mystical feel to it. But the themes of societal and ecological break-down, and how people cope with these, are common to both books.

 

 

 

 

skulls & braaiiinz – what’s not to like? (also, plants) Alison Campbell Jan 03

No Comments

The intrepid reporters from Number 8 Network e-mailed the other day. “What are you reading?” they asked; “after all, it’s the holidays & you must have heaps of time to put your nose in a book.” Which is sort of right, it is the Christmas/New Year break, but the days just seem to fly by when you’re doing not very much at all.

However, as it happens I’m working my way through several books at the moment, so I was able to oblige.

First up is Skulls, by Simon Winchester. Strictly speaking it’s not actually a book but an interactive iPad app, based on the enormous personal collection of Alan Dudley. I bought it because I find skulls fascinating (though not so obsessively fascinating as I think they must be for a collector of same) & the blurb at the app store offered me the ability to zoom in, out & around a whole bunch of bony brain protectors. This, I figured, would be quite fun & could also be a useful teaching tool (I’m looking forward to showing it to a colleague who teaches 3rd-year zoology).

And the ability to examine skulls in such detail really is great, although – a minor quibble! – I would have liked to be able to look at them from beneath & above as well as from all sides. You lose some definition at high levels of zoom but apart from that, wow! I would otherwise not have known that the Atlantic wolffish has quite so many teeth (shades of an aquatic Red Riding Hood villain) & such a wonderfully architectural skull. Or that a rabbit could somehow have lived long enough for its incisors to grow backwards & inwards in curves reminiscent of reversed (& miniature) elephant tusks.

The chapters comprising the ‘book’ struck me as a bit of an eclectic mix: we’ve got an interview with the collector himself, followed by an essay on the nature of collecting. Then, after learning about what a skull actually is & the bones that make it up, we find out about the dodo, or the pseudoscience relating to skulls – wherein we can learn about Piltdown man & phrenology but not, to my surprise, the various claims about ‘alien skulls’ from South America. Or the iconography of skulls, or skulls in art & in Mexico, & so on. One of the nice things about apps like this is that – even less than with a ‘real’ book – you don’t have to follow a linear progression through the text but can dip in & out, & that there are nice little visual cues to guide you in your choice of where to go next.

Not a lot in the text that was completely new to me, but well worth the price (at $17.99 this is one of the more expensive iPad apps) for the sheer enjoyment to be gained from viewing the images.

As for the brains – I’m also working my way through a Kindle edition of Carl Zimmer’s Brain Cuttings. Zimmer is one of my favourite science writers & this collection of essays (mostly written originally for Discover magazine) hasn’t disappointed me. The first essay’s title is from a question asked by Charles Darwin of one of his many correspondents. Wondering whether people around the world expressed emotions in the same way, Darwin asked, “Does shame excite a blush?” From this starting point, Zimmer takes us through scientists’ current understanding of the evolution of the face, a feature that began to form around half a billion years ago with the appearance of the earliest fishes. He asks why primates, in particular, have such complex, expressive faces – something that has to do with the complex social behaviour of this group of mammals. It turns out that facial mimicry is part of that social behaviour – and apparently the ability to mimic someone else’s facial expression, however briefly, may well be important in allowing us to understand how that person is feeling. An interesting experiment certainly suggests this:

[Researchers] had volunteers bite down on a pen and then look at a series of faces. They had to pick the emotion they thought the faces were expressing. The volunteers could recognise sad faces and angry ones with teh same accuracy as test subjects who did not have pens in their mouths. But they did a worse job of recognising happy faces.

Biting a pen, it just so happens, requires you to use the same muscles you use to smile. Because the smiling muscles were active throughout the experiment, [the research] subjects apparently couldn’t reel themselves start to mimic happy faces. Without that feedback, they had a more difficult time recognising when people were happy.

And that’s just the first chapter! The second essay, “The googled mind”, is an exploration of just where the mind stops. As Zimmer remarks,

[we] tend to think of the mind as separated from the world. We imagine information trickling into our senses and reaching our isolated minds, which then turn that information into a detailed picture of reality… In fact, teh mind appears to be adapted for reaching out from our heads and making the world, including our machines, an extension of itself.

In other words, it looks like the ‘mind’ is more of a complex system that comprises both the brain and various bits of its environment – books, for example, or computers, iPads – and even the tools we use.

This book’s both entertaining & informative & I’m enjoying reading it, one chapter at a time.

Third on my list is an actual, print-on-paper, hardcopy book: Fifty plants that changed the course of history, by Bill Laws. I bought this on a colleague’s recommendation, because of all the topics I teach at first-year level, botany seems to be the one that students are least engaged with, & I was hoping for some nice new examples to add my list of ‘cool stuff about plants & how they changed our world’.

My impression of this book is that it’s a bit like the curate’s egg: good in parts. My copy is a beautifully presented hard-cover edition, with lovely illustrations & some fascinating snippets of information (for example, that pineapples were grown in England over pits full of fresh dung! (This generated heat as it rotted, & augmented the warmth from stoves.) And the idea of a bamboo bicycle is an intriguing one. I’m enjoying dipping into it, a couple of plants an evening.

But unfortunately that enjoyment is tempered by moments of irritation. OK, I know I’m simply being greedy in wanting to know more about some topics than can be fitted into the 2 or 3 pages accorded them here. That’s a minor one. But saying that plants “absorb carbon dioxide and exhale oxygen” glosses over the fact that plants need that oxygen for cellular respiration as much as we do. (All too many of my first-years share this particular misconception.) And what am I to make of the following statement ?

The oldest names for the coconut are in Sanskrit, pointing to India as the source [of this plant]. However, the discovery of the fossilised remains of a tiny proto-coconut on New Zealand’s North Island suggests it might have been first taken into service here 5,000 years ago.

Five thousand years ago, there weren’t any people in New Zealand; hence no-one to take anything ‘into service’… (Interestingly, Sir Charles Fleming notes that a fossil coconut dating to the middle-late Miocene was discovered in Hawkes Bay; this would give an age of around 5-10 million years.)

So, I’m accumulating some new stories to tell in class, and I am enjoying the read, but – unlike Skulls and Brain Cuttings – I probably won’t be recommending Laws’ book to students looking for a bit of extra reading. At least, not until I’ve finished it & identified any other potential pitfalls. Although… I guess the error I’ve picked up on here would be a useful jumping-off point for a discussion of New Zealand’s botanical history.

B.Laws (2010) Fifty plants that changed the course of history. Firefly Books. ISBN: 978-1-742372-18-1

S. Winchester (2011) Skulls. Touch Press.

C.Zimmer (2010) Brain Cuttings: fifteen journeys through the mind. Scott & Nix Inc. NY ISBN (Kindle): 978-1-935622-16-1

teaching what you don’t know Alison Campbell Sep 10

No Comments

I’ve just finished writing & delivering a new set of lectures; next week we’re moving back into what is – for me anyway! – more familiar territory. At the same time I’ve been reading Therese Huston’s book Teaching what you don’t know. Huston’s examples are drawn from the US tertiary system, and as you begin reading it quickly becomes apparent that ‘teaching what you don’t know’ is a common occurrence for teachers in that sector. (And I really do mean, ‘what you don’t know’: a science lecturer teaching a general writing course, for example. At least I’m still teaching biology!)

One of the Big Questions in a situation like this is, what & how much do you tell your students? Huston notes that in some circumstances a lecturer might not want to let on that they’re teaching at the fringes of their expertise – perhaps they’ve previously felt that their authority or credibility have been challenged by students, & letting on now isn’t going to help the classroom dynamics.

Personally, I prefer to put a positive spin on this experience. First up – I’m still teaching biology, albeit an area that’s moved on a bit since I studied it. I’ve had to do a lot of extra reading, but I have the considerable advantage over the students in that I’ve already got the mental constructs into which I can scaffold my new learning. Now that I think about it, the immediacy of that learning helps me to help my students make sense of this new material as they encounter it themselves.

There’s also the fact that the pace of scientific discovery is such that it’s highly unlikely anyone could keep up with it. We don’t have the luxury of reading papers all day, every day, so we try to read the key papers, especially those in our own areas of expertise, and know with regret that there are bound to be others that we’ve missed. So the odds are good that every now and then, a curious, deep-thinking student is likely to ask a question that challenges & stretches your own understanding. The big thing is not to be thrown by this.

Huston gives a number of strategies for dealing with the challenge of teaching what you don’t know, drawn from interviews with a number of expert teachers who routinely teach outside their immediate field of expertise – & relish the challenge of doing so. One of these teachers, speaking of how quickly our knowledge of science moves on, comments that

“… we know different kinds of things, things that were unknown in 2005 we’re certain of now. And now we know that some of what was true in 2005 was wrong. They were hypotheses and we now have the data. It’s a lot of fun because students know I’m learning along with them, and we’ll say “What have we learned? What are people thinking about right now? What are the big questions that are left?”

As that lecturer said, learning new things – while challenging – is also stimulating & fun. If that sense of excitement and enjoyment carries through to your actual classes, then you’ll speak with passion and enthusiasm – how better to in turn enthuse your students?

What’s more, the mere fact of expressing uncertainty can help students learn something of the nature of science. Don’t stop at saying ‘I don’t know’ to that curly question; take it further: ‘I don’t actually know the answer to that question, it’s a bit outside my field of expertise. But I do know that in these circumstances so-&-so would happen, so I can hypothesize that such-&-such might happen in the circumstances you describe.’ And that’s a rather satisfying learning experience for everyone :-)

T.Huston (2009) Teaching what you don’t know Harvard University Press

Network-wide options by YD - Freelance Wordpress Developer