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.


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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