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.

I have trouble deciding what to do with this next one. To create a narrative in Whales: An Unforgettable Journey, Chris Palmer filmed different humpback whales in Hawaii and Alaska, but presented them as the same mother-cub pair followed over the course of their annual migration2. The CBC site has a timeline of other well-known examples.

I asked students in the history of biology course whether they thought staged scenes could be justified. About 1/3 of the class said no. The other 2/3 gave a cautionary yes, as long as it comes with a disclaimer. Some said it could be justified in situations where disturbing organisms in the wild might cause real damage. One added the stipulation that staged scenes were only permissible when based on scientific studies of natural behaviour.

Many of the students pointed out that fakery can be useful if it promotes awareness or excitement about things that are impossible to capture in the wild. The spectacular “woodland timelapse” scene from the “Plants” episode of BBC’s Life series is a perfect example of this.

When I asked the group whether distorting biological reality could be justified in the classroom, the results were almost identical to the previous question. Nearly everyone who said yes to that question said yes here as well. About 2/3 thought simplification is permissible if it comes with a disclaimer, or if it is limited to the earliest stages of education, and the whole story will be eventually be presented. The rest were firmly on the no side: science aims for an objective view of reality, and science education should follow suit.

Consider the peppered moth story, one of the textbook examples of evolution by natural selection. In the 1800s, coinciding with the Industrial revolution, British naturalists noticed a shift in the peppered moth populations with a dark-coloured “carbonaria” form taking over. This pattern reversed in latter half of the 20th century. The standard explanation is that with rising industrial pollution in the 1800s, trees became covered in soot, giving darker moths a camouflage advantage. The new “carbonaria” form suffered less predation, so the populations evolved. With the decline of coal-burning factories and emissions regulations in the 1970s, this pattern began to reverse. The environment in British forests shifted back to favour the lighter coloured moths. Once again, they are the more common form today.

But the real story is not so simple. As Jonathan Wells points out in this article3, peppered moths are probably not picked right off of the sides of trees by predators, as the classic story suggests. Wells reveals that the photographs commonly seen in biology textbooks are fakes, with dead moths were placed on the sides of trees artificially. The early experiments demonstrating differential predation on moths were not very realistic, either: some were done in aviaries, at a time of day when moths are not typically active; others used dead moths that were pinned to the trees like in the textbook photographs. Wells argues that the photographs, and the peppered moth story, should be taken out of the classroom altogether.

So how damning is Wells’ critique? Simplification is a necessary part of experimental control. In the case of peppered moths, the early predation experiments might not be perfect, but they are just a small part of a research program that has spanned decades. Scientists today are continuing to work out the effects of other factors in the evolution of the peppered moths in the UK, such as dispersal, using sophisticated genetic techniques4. We accept differential predation despite the flaws of the early experiments, but no-one would claim that the story ends this way.

In fact, convenient fictions like these are found throughout science education. Take the “ball and stick” model of molecular bonding in chemistry. It gets replaced by a series of increasingly sophisticated views as you advance through high school and university chemistry that, presumably, get closer to objective reality with ever step.

Science is full of metaphors, too. Richard Dawkins has given us some of the best: the selfish gene neither implies that genes are selfish nor that we are5. Mount improbable is his metaphor for the peak of adaptation on a landscape of evolutionary possibilities.

By far the most common metaphor in biology is the idea of intention, or a designer, in the process or natural selection. We speak of an organism “wanting” a particular outcome in evolution as a convenient way to emphasize who benefits and what exactly is in their best interest – even when there are no desiring minds involved.

Sometimes the only thing we know for certain is that things are not as simple as our metaphors suggest. I was surprised to learn recently that the nature of chemical bonding is still a major bone of contention6. Surely a field full of useful, tangible results like chemistry shouldn’t have the deep philosophical schisms of evolutionary biology. Apparently, even the most recent definitions of “bonded or not” are based on approximations, and the concept gets murkier when you start talking about large molecules. Debates about whether atoms are bonded or not in certain molecules are ongoing on in the scientific literature6. As Charles Coulson, author of the 1950s chemistry textbook “Valence” put it:

A chemical bond is not a real thing: it does not exist: no one has ever seen it, no one ever can. It is a figment of our own imagination.see 6

The gene might also be considered a metaphor. We know that the basic concept of a segment of DNA that codes for a single protein is a major oversimplification. Protein expression can be influenced by other genetic regions, sometimes located in regions of DNA that are far from the coding sequence, sometimes on an entirely different chromosome. Other chemicals in the cell can also influence gene expression in a heritable way.

Here’s what I think: these fictions are incredibly useful. Metaphors allow us to offload some of the mental effort required to unpack sentences that, if stated literally, would be far too complex and demanding. A well-placed metaphor helps you to take in the bigger picture. This can be essential for teaching, but it is also useful for looking at a familiar subject in a new way. Scientists benefit from efficient communication and imagination, too. The key is that everyone in the audience has to be in on the metaphor, otherwise they just get taken for a ride.

As in Hollywood, inspiration is a major and noble purpose, but metaphors can have real consequences. Creationists and intelligent design fans love picking up on sloppy use of the design metaphor to try to undermine evolutionary biology. In the case of chemistry, the way scientists conceive of the bond will probably influence what they think they can create6.

I would argue that it is the responsibility of teachers and popularizers to be judicious about when, and how, they apply these fictions. People who know better should correct misuse. It may be the only way to save the metaphor for everyone else.


  1. Rumak, O. J. “Cruel Camera”. The Fifth Estate. 16 January 2008.
  2. Donovan, J. et al. “Rent-a-Wolf”. Abc News. 28 September 2010.
  3. Wells, J. 1999. The Scientist 13: 13.
  4. Saccheri, I. J. et al. 2008. PNAS 105: 16212-16217.
  5. Ruse, M. “Genetic Generosity”. The Globe and Mail. 12 September 2009.
  6. Ball, P. 2011. Nature 469: 26-28.