Month / January 2011

by Roslyn

Science fictions

Fakery is not just for Hollywood films anymore.

Nature documentaries are full of it, from elegant narratives to some downright dirty tricks. This tradition goes back a long way: the myth that lemmings commit mass suicide to save their brethren from overpopulation was spread widely as as result of the 1958 Disney film White Wilderness. This is not trivial. The film won an Oscar for Best Documentary. The lemming story made it as far as a philosophy course I took in university (Science and Society PHIL203), where the instructor used it as an example of why we should doubt evolutionary explanations of human behaviour. The myth just won’t die, even though CBC exposed the lemming scam back in 19821. Journalists on The Fifth Estate proved that the mass suicide scene was actually filmed in downtown Calgary, not in the Arctic as Disney had claimed. The Disney crew used a rotating platform to push captive lemmings into the Bow River.

More recently, the BBC has come under fire for using captive animals to film some of the scenes in the Blue Planet series1. This seems justifiable to me, but some truly ugly practices have also been exposed, like baiting corpses with M&Ms to get footage for an IMAX documentary on wolves2.

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by Roslyn

Field biology goes to Hollywood

One of the weirder things about my field site is that it is also a Hollywood set. A number of movies, TV shows and commercials have been filmed at the LA Arboretum, going back to Tarzan Escapes in the 1930s.

The Arboretum had a regular appearance in the popular 1970s show Fantasy Island. In the opening credits, a midget rings the bell in the Queen Anne Cottage. This is a historic building on the Arboretum grounds that was built in the by the same wealthy California businessman who started the peafowl population in the area.

You can catch the Arboretum in many other films, since it provides a convenient stand in for the jungle a short drive away from downtown Los Angeles. Examples: The Lord of the Flies, Anaconda, The Lost World, Congo, Terminator 2, The African Queen, and too many campy horror flicks to count (Attack of the Giant Leeches?).

Several things were filmed during my three seasons there, leading me to realize that making a movie is a lot like doing field biology. Here’s how:

1. The hours. Field biologists often have to keep the same hours as their study species, working for as long as the animals are active. For some ornithologists, this can mean starting at 4 am. We were lucky with peafowl. They are late risers, coming down from their roosts around 7-8 am. They also tend to take a long siesta in the middle of the day. This meant that we had to work two shifts, coming in for several hours in the morning and returning after lunch until sunset. It made for some long days.

Film crews also seem to work long hours based on the amount of light, since our schedules would often coincide.

2. Tedium and futility. Most of the time spent watching animal behaviour is watching them do very little. Here’s an example: we saw about 20 mating events in 2010, in 500 man-hours of observation time. That’s over 24 hours of sitting quietly for each copulation.

Catching the beasts can be a little bit more active, but you still feel completely useless 90% of the time. Your main activities include: waiting for the animals to show up, looking for the ones you haven’t caught yet, waiting around for your traps to work, and worrying about all the reasons why they aren’t.

A lot of jobs in Hollywood might not be so far off. When AT&T filmed a commercial at the Arboretum last year, we met a guy whose sole responsibility was to keep the peacocks away from the set. His boss gave him a bag of bird seed. It was the cusp of the breeding season, and the crew had decided to place their set right in the middle of one particularly dedicated male’s territory. The poor guy was literally playing tag with that bird all day.

3. Costumes. Important in Hollywood, but also useful when trying to catch birds. After a few weeks in the field, most tend to settle in to a uniform, wearing the same thing nearly every day. If it works and you’ll just be getting dirty again tomorrow, why change?

Field clothes

Waterproof jackets come in handy when catching large birds. From left: Will Roberts, Myra Burrell and Roz Dakin. Photo by Bonny Chan.

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by Roslyn

Evolutionary rescue

Can evolution save us from the brink of collapse?

Andy Gonzalez thinks so. Gonzalez, an ecologist from McGill University, gave an entertaining seminar to the department last Thursday on the subject. His research group works on the causes and consequences of biodiversity loss, using mathematical models and controlled experiments to investigate how environmental change might affect populations.

Gonzalez teamed up with McGill’s Graham Bell, who is known for using simple systems like yeast and algae to tinker with the evolutionary process through experimental evolution. Gonzalez describes their third collaborator on this project as “painful to work with, but once things were up and running [he was] amazing.” He was, in fact, a robot.

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by Roslyn

How to raise a science major

The newspapers have been abuzz lately about a controversial book: Battle Hymn of the Tiger Mother, by Amy Chua, is a memoir on the rewards and perils of stereotypically strict Asian-American parenting. This week I asked students in my 4th-year biology class to tell me about their earliest memory of being fascinated with something biological, information that could be useful for parents hoping to form their children into university science majors.

And so, some lessons learned:

1. Worms work. Let your kids get close to the ground, outside. At least two students listed earthworms appearing after the rain as their most important early memory. A large portion of the class described similar encounters with tadpoles, snails, caterpillars, ants, spiders and their webs, and other minutiae found on the lawn. Larger examples of charismatic megafauna barely got a mention. Perhaps opportunity plays a role. For instance, one student remembers being particularly enamoured with deer in the backyard.

2. Pain. A wise teacher once told me that “learning hurts”. The converse might also be true: harmful organisms can be educational. An encounter with razor-sharp zebra mussels was particularly salient for one student. Another recounted a family vacation in the New Mexico desert, where a first-hand experience with cacti led to an early lesson in adaptation.

Well-armed cacti

Hidden Valley, Joshua Tree National Park, California.

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by Roslyn

Beware of the blob

It creeps, and it might be more like us than we care to admit. That was a lesson I learned last fall when trying to choose between pigeons and slime moulds for our lab journal club. The birds, it seems, are on a different level.

It started with the Monty Hall problem and a new study that asks, “Are birds smarter than mathematicians?”1. For those not familiar, the Monty Hall problem is a puzzle made famous by columnist Marilyn vos Savant, based on the popular 1960s game show Let’s Make a Deal (which was, incidentally, hosted by Winnipeg-born Monty Hall). Here it is:

Suppose you’re on a game show, and you’re given the choice of three doors: Behind one door is a car; behind the others, goats. You pick a door, say No. 1, and the host, who knows what’s behind the doors, opens another door, say No. 3, which has a goat. He then says to you, “Do you want to pick door No. 2?” Is it to your advantage to switch your choice?2

If you were on Let’s Make a Deal, would you take Hall’s offer to switch doors? Or would you stand by your original choice?

Let's Make a Deal

Does it make any difference?

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by Roslyn

What should Stephen Harper know about biology?

I’m teaching again this semester, this time in Bob Montgomerie’s fourth-year course on the history and philosophy of biology. My job is to moderate group discussions and seminars in the tutorials. It will be a lot of work, since tutorials happen every week, but I’m excited at the prospect of using our debate as fuel for this blog.

I started by asking the class to answer three questions in an anonymous survey. First, I wanted them to tell me the most surprising thing they had recently learned about science.

My example of this was the nocebo effect. it’s the opposite of the placebo effect, with a bit of voodoo-witchcraft thrown in: apparently just believing in a negative outcome can be bad for your health. What I found surprising about it initially were the spooky anecdotal accounts of people diagnosed with terminal illness, and then dying within a few months just as the doctors predicted – only to have pathologists later realize that the original diagnosis was in error. Can we think ourselves to death?

But maybe this was a bad example. In general, the power of negative thinking isn’t all that surprising. Why shouldn’t there be a flip side of the coin for the placebo effect? After all, the negative effects of stress and anxiety on health are well-documented by the medical community. For example, this Washington Post article describes a study on blood thinning drugs where doctors showed that just by giving patients a warning about gastrointestinal side effects, you can make it much more likely that they will experience those negative symptoms. Other documented nocebo effects in the Skeptic’s Dictionary range from headaches to allergic reactions. Again, the power of thought to affect us via our own immune systems is perhaps not so surprising.

Voodoo may have lost its magic too: according to this article from Salon, there is some debate as to whether examples of death by curse in tribal societies are really due to starvation and dehydration, since feeding the doomed individual is often seen as a waste of scarce resources. And of course, the medical anecdotes of death by false diagnosis are good stories, but probably not much more than eerie and highly memorable coincidences.

What do the students find hard to believe? Out of 28 responses, 4 had to do with the paradoxical nature of modern physics. There was 1 response on lemmings that was certainly hard to believe, because it was just plain wrong (more on that later, but lemmings do not jump off of cliffs in a form of altruistic mass suicide. That is a myth). The majority, at 14, were on marvels of adaptive evolution (e.g., the complexity of the brain, venomous mammals like the platypus, bowerbirds, examples of rapid evolution).

This is proof that majoring in biology does not diminish the sense of wonder we have about living things. If anything, it probably enhances it. Here are two student responses that sum it up nicely: the “diversity that surrounds us” and “just how much there is out there to learn”. It may be the hardest thing about biology to really wrap your mind around, but it sure is fun to try.

The second question: What should Stephen Harper know about biology?

The most popular category here was the environment, with 13 students listing principles of ecology and environmental science that Harper could use. After that, 4 wanted Harper to have a basic grasp of evolution and natural selection, especially given the strange opinions of his science minister Gary Goodyear. There were 2 shameless requests for more research funding. Sadly, 2 left this one blank – hopefully not because they think Harper doesn’t need any biology. At the other extreme, 1 complained that there is a lot Harper should know about “any matter really”. One student wants him to have “a dangerous idea like Charles Darwin”.

I would tell Stephen Harper that Taq polymerase comes from Yellowstone National Park. Everyone should know this one – I’m sure I learned it during undergraduate, but forgot, only to be reminded of it again recently.

Here’s the story: Taq polymerase is a chemical we use to study DNA. A workhorse of the modern genetics lab, this enzyme makes it possible to turn a minuscule amount of DNA into a much larger sample by rapidly copying the molecules at high temperatures in the polymerase chain reaction (PCR). Countless techniques are made possible as a result: forensic DNA fingerprinting, diagnosis of genetic diseases, unraveling gene functions, sequencing whole genomes, and filling in the branches on the tree of life that describes how all living things are related to one another.

Taq polymerase works at high temperatures because it comes from Thermus aquaticus, a heat-loving bacteria. Up until the 1960s, the temperature threshold for life was thought to be around 73 degrees Celsius (which is the limit for photosynthetic bacteria). However, in 1967 Thomas D. Brock and Hudson Freeze reported finding bacteria that could withstand temperatures a lot higher than that in the hot springs of Yellowstone. This was revolutionary. Years later, when people were working out the chemical procedures necessary for DNA analysis, it was knowledge of the earlier Yellowstone discovery that made efficient DNA copying at high temperatures possible.

I also asked the students what they hoped to get out of the course. Only 1 claimed a good mark, which was surprising for an anonymous survey. Some emphasized novelty: to learn “something new in biology for once”, “something stimulating and eyebrow raising” and “ideas never thought of before”. Others hope to learn some personal and biographical details of the iconic figures in science: “what inspired them” and “what was going through their heads when their ideas were opposing the popular belief of their time”. I hope I can learn from this group about what goes on in the heads of students and the public in Canada.

by Roslyn

Reaching the other side, in synchrony

It’s a familiar site on campus here during the first week of class: packs of jaywalkers moving in tight co-ordination, in sync with the flow of oncoming cars. From traffic lights and power grids to stereo sound and cinema, synchrony is so common in our environment that we usually only notice it when it fails. Not so with nature: the examples of synchrony in living things tend to be much more surprising to people studying animal behaviour.

Group courtship displays are a classic example. Think of chorusing songbirds in the morning or calling frogs gathered around a pool of water at night. Readers of my blog on peacock field work might be familiar with lek-mating birds gathered around a clearing to wait for females. Peacock train displays also tend to happen in sync. One traditional explanation for these co-ordinated displays is that, by synchronizing their most conspicuous behaviour, animals might gain some protection from predation1. Another possibility is constructive interference: co-ordinated timing might allow a pair of animals to spread the message farther than either one could on its own2. Two innovative new studies on animal courtship have added to this list. The first, on firefly displays, shows that synchrony might help insects recognize members of their own species by getting rid of visual clutter.

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by Roslyn

Honed

We brought home a new kitchen knife from my parents last month. The knife block was full, but Charlie exchanged the new one for what was previously our smallest and dullest. He wasted no time wrapping the old one up in plastic and hiding it from me. My hand naturally gravitates towards whichever tool will fit nicely inside it, even when I’m cutting a monster squash. We have a good arrangement: Charlie keeps the knives sharp, I keep my fingers, and I toss him the odd carrot slice in return.

But could he eventually be replaced by a sea urchin? A new study in the journal Advanced Functional Materials explains how sea urchin teeth never dull or break. In fact, they get sharper with use1.

Most people are probably familiar with sea urchins as the spiny little balls one occasionally encounters on the beach. Evil looking, but mostly harmless, so long as you avoid stepping on them. Sea urchins live in shallow tidal pools, eating algae and other plant material. So why do they need such sharp teeth? Much like their spines, the teeth probably serve a protective function. The urchins use them to chew burrows, often in solid rock, where they can take shelter from predators and waves.

In the current study, a group of physicists and biologists used an arsenal of sophisticated imaging, chemical and nano-scale stress test procedures to investigate the teeth of the California purple sea urchin (Strongylocentrotus purpuratus). Like starfish and sea cucumbers, urchins are members of a group of animals known for their penta-radial, or five-fold, symmetry. They have five teeth arranged in what is known as Aristotle’s lantern.

Aristotle's lantern

Aristotle’s lantern, as viewed from below with teeth closed. From Killian et al. 20111.

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by Roslyn

Masters of illusion

It can be easy to see intelligence in the animals we spend a lot of time with. Everyone has their pet example, one of the most common being dogs who can anticipate the precise time of their owners’ return. But what does this really say about the mental life of dogs? Some birds are capable of even more impressive mental stunts – only they often go unnoticed in the wild. Two recent field studies in Africa and Australia provide a nice illustration. The results challenge our notion of limited animal intelligence, but as we will see, the way we interpret them might say more about our own minds than it does about the birds.

Fork-tailed drongos are masters of deception. These small, glossy black birds from southern Africa are known for their ability to mimic the calls of other bird species – much like the mockingbirds found throughout the US and parts of southern Canada. Most of the time, drongos forage alone hunting insects, but occasionally they get other animals to do the hard work for them. Drongos will follow groups of meerkats and pied-babblers – mammals and birds known for their highly social lifestyles – and steal their food, a process known as kleptoparasitism. It might not be a complete loss for the victims, either. Drongo thieves give plenty of alarm calls along the way, and these may help the meerkat and babbler groups avoid predation1.

Perhaps not surprising for an accomplished mimic, the fork-tailed drongo has a diverse alarm call repertoire that includes its own unique warning “chink” as well as the calls of several other bird species. On the savannahs of the Kalahari Desert, birdwatchers noticed that drongos often seem to use these mimicked calls during kleptoparasitism, swooping in to steal food from pied-babblers immediately after sounding a false alarm1. For Tom Flower at the University of Cambridge, this was fascinating anecdotal evidence, so he set out to test whether these alarm calls are used by the drongos in a deceptive way2.

The first thing Flower needed to do was eliminate the possibility that the drongo false alarms are coincidental. If the drongos are truly deceptive, the calls should only occur when the birds are attempting to steal food. Flower also had to establish that the drongos sound the same, regardless of whether they are using their alarm calls in an honest or deceptive context. Finally, he had to show that the meerkats and babblers respond similarly in both cases.

Fork-tailed drongo

Fork-tailed drongo.

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by Roslyn

Shark Lady and the convict fish

Who’s weirder: the shark lady or the convict fish? It may seem a strange way to get this blog started again, but it turns out to be quite fitting this time of year when we find ourselves cooped up with relatives of all stripes.

My first encounter with the convict fish was this summer. It was one of those enigmatic creatures that blew all of the biologists in the room away, at one of our regular gatherings to watch the BBC’s Life series. Over images of thousands of tiny fish emerging from a burrow on the sea floor, David Attenborough explained the mystery. This was a swarm of siblings, all offspring of the same pair of adults who spend their entire lives in a tunnel. Each day, the young convict fish head out to forage on plankton around the reef, returning home at night. Biologists have no idea how the parents feed, though, because no one has ever seen the adults leave their burrows in the wild. Attenborough left us hanging, suggesting with intrigue that the young fish might have something to do with it.

Could the convict fish be living off of its own offspring? A bit grim, yes, but also a fascinating biological paradox – perfect for this blog on the stranger twists of evolution, I thought. In nature, it might not even be that unusual. The males of plenty of fish species feed on eggs from their own nests. By taking in extra resources, this might allow them to invest more in future nesting attempts1. In fish with especially large broods, once filial cannibalism gets started it could get an evolutionary boost from the fact that many of the offspring in dense egg masses will not survive anyway2.

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