Don’t spoil the ship

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Guest post by Jim Deed

I like a good nature documentary – especially those that delve more deeply into biology and ecology than merely saying “Cor blimey, ain’t nature amazing?” TV ratings show I’m not alone.

Image by  Remember the dot
Image by Remember the dot

But, more and more, I’ve noticed a worrying thing about these shows when they start talking about evolution. It’s at about this point on a Sunday eve when I begin foaming at the mouth and raving at the tube such that my kids run and hide and my wife suggests I might like a cup of tea and a good lie down. Please don’t take this to mean that I’m some “Intelligent Design” fanatic: it is just that, more often than not, otherwise well-credentialed presenters start talking about organisms evolving as if they intended to do so.

A case in point: a doyen of evolutionary biology suggested on a very recent doco that horses evolved to run fast so that they could get away from predators. Another recent high-production-values show indicated a very similar rationale for plants evolving thorns. To me, this is putting the cart before the appositely proverbial. Granted, faster horses or thornier plants were probably more likely to survive and reproduce, but to suggest that they chose to do so runs counter to evolutionary theory as I understand it.

New woodlice species whose distribution is restricted to mound springs in South Australia (A. Austin)
New woodlice species whose distribution is restricted to mound springs in South Australia (A. Austin)

It’s possible that I’m crying wolf, but this type of goal-oriented, purpose-driven slant on evolution seems to be becoming the norm. I fear the elegance and utility of evolutionary theory is being undermined by such unpolished public interpretations; the journey from Lamarckian “purposeful evolution” to the outer shores of Intelligent Design unreason is not a long one for the viewing public to take.

There’s an old saying, “Don’t spoil the ship for a ha’penny worth of tar”. Like a ship, the theory of evolution has taken many years and many hands to build. And if we can’t take that little extra time to explain evolution properly, make it “seaworthy”, then we share some of the blame for people getting on the wrong boat.

[Featured image: Photo by Jayant Kulkarni on]


  1. I agree Jim, but I think part of the problem is it is much easier to talk about evolution as if it’s purposeful and (most of) the people that talk about it in this way expect the listeners not to take it literally. It’s as if they expect that everyone has a good enough understanding of evolution to know that when they say “horses evolved to run fast so that they could get away from predators” what they really mean is “faster ancestral horses were better at outrunning predators than slower ones and so the slow ones got caught and eaten whereas the faster ones survived and reproduced, resulting in a higher proportion of faster ancestral horses in the next generation due to the successful transmission of genes which bestow the horse with the ‘fast’ characteristic. An evolutionary arms race develops between the ancestral horses and their predators, with the selection pressure to run faster to escape their predators or capture their prey” – bit of a mouthful. However, many people do not have this understanding of evolution and so, as you point out, come away from watching the documentary with this idea that evolution is purposeful. Having been a high school biology teacher, I have spent many lessons attempting to unpick students’ misconceptions about evolution that they’ve developed from watching such docos!!

    1. Completely agree Matt. Many people would have heard about the KISS principle in communicating ideas, but as you say it runs the risk of leaving a rather large chasm of mis-understanding between the speaker and the audience. My fear is that if we persist in spreading the concept of ‘purpose’ in evolution because it’s “easier”, then it’s actually a very small leap to ‘design’ in an audience member’s mind. In that fraught space, there will be a certain number implacably welded to the design concept and it won’t matter what we say or do. But, more importantly, there is likely to be a large number of ‘swinging voters’ open to more thorough explanations, and would you agree there’s no better time than now to get cracking on better ways to communicate the concept?

      1. You’ve both got a point, and in one sense you’re both saying the same thing: that evolution, while quite a simple concept in itself, has traps for the young player.

        Using Matt’s horse analogy, any explanation that runs “horses evolved to faster to avoid predators” also runs the risk of being hit with the response “Well, why didn’t they grow wings then?” and so forth, which roll quickly into the deliberate design swamp.

        I think it’s better to say “faster horses survived longer, so there were more fast horses in later generations, and so on” then draw in the corresponding race on the predators’ side.

        Although given that true believers in ID aren’t likely to be swayed by rational arguments, I’m not sure how much energy we should be expending. I’m sure you’ve seen The Atheist’s Nightmare, where some guy claims that the shape of a banana is indubitable proof of (a) God, and (b) intelligent design – what can you say there?

  2. Yes, you’ve provided a good example (the horses, not that banana thing) that it’s not that difficult or time consuming to explain it better. But I also strongly believe expending the energy *is* worth it. My original post was not really about convincing dyed-in-the-wool ID’ers – that’s an oil and water situation – but could well be a ‘lightbulb moment’ for the oodles of people who are interested in nature and science, and are open to learn.

    1. Yeah, I think if someone truly believes that a banana is the shape it is because that’s how ‘God’ designed it so that it can fit in a human hand and be easily pealed then it’s probably too late to convert their thinking – unless by ‘God’ they mean humans playing ‘God’ through the use of artificial selection.

      So Jim, how do we get evolutionary biologists who are in the public eye to stop talking in metaphors and start explaining things properly?

      1. I think a lot of us are lazy when we speak, or at least use a sort of verbal shorthand that we assume our listeners are aware of. But trying to get evolutionary biologists (or any other scientists, barring mathematicians, who are always precise ;-)) to be accurate with their terminology can lead them to being overly pedantic and losing their audience altogether (much like mathematicians – never admit to having studied maths when you’re at a party).

        And vis a vis BananaMan, it’s just lucky for him he didn’t try arguing using a durian…

      2. Thanks Matt. I think there are probably three broad levels of fairly simple action that could be taken.
        1. Personal self-reflection: when preparing a presentation or publication, put yourself in the intended audiences shoes and assess if the richness of the message is likely to get across…probably a good idea whatever the topic and/or medium…
        2. Proximal sphere of influence: it’s often the case that you’ll review work colleagues’ communications (e.g. practice talks or proof reads), and the issue can be raised then if warranted to polish the final product.
        3. Wider sphere: Contribute to/raise discussions like this one in appropriate fora…of course you may want to apply such action judiciously otherwise you might be a) slated for Associate Dean, or b) asked if you could get a head start on washing up the meeting coffee cups…the latter is, of course, the more preferable alternative.

  3. One of my pet hates! I always imagine the species having a collective consciousness and thinking, hmmm, I keep getting eaten by predators, I really need to evolve faster legs. If evolution really was purpose-driven we would never have ended up giving birth to such big headed babies – pregnancy and child birth is a very dangerous time for women. Would have been so much more sensible to swap gestation for lactation like the marsuipials, get ourselves nice warm pouches to nurture our young. Our current situation is a strong argument against intelligent design.

    1. Thanks for the comment Wendy!
      On a related note I had a recent discussion with someone who was asking, “how could Galapagos marine iguanas just ‘invent’ their salt glands to excrete unwanted salt?” (which the iguanas somehwat amusingly snort out their nostrils with great gusto).
      The simple (some might say simplistic) answer being a) salt glands weren’t invented de novo, they evolved from a previously existing capability, and b) the evolutionary time-scale is almost beyond our ken.
      Although I’m not an expert on salt glands (or much at all), marine fish, as an example evolutionary predecessor to reptiles, are generally able to get rid of the excess salt that enters their system.
      If the question then becomes, “how did the previously existing capability come into being?”, the answer is (also simplistically with a dash of facetious glibness for taste), “the answer previously supplied”.
      I could go on to make the rather bold assertion that this argument also effectively accounts for the origin of life…

    2. I tend towards the ‘infinite number of monkeys’ type of theory: when you have such a mind-boggling time scale, the occasional beneficial random mutation out of all the multiplicity of mutations can give sufficient advantage that eventually, the descendants of that mutation win out over the rest.

      The argument that makes me most cranky is the “well, look how complex the eye is: did that just pop into being? No, therefore intelligent design, QED (which one of my maths lecturers always referred to as “quite enough done”).

      This completely ignores all the steps along the way between simple light-sensitive patches, through eyespots (mentioned in today’s post about hagfish), through simple lenses to focus, and so forth to the eyes we know and love.

      Which is just a more verbose and less amusing version of Jim’s answer – a succession of successful mutations leads to where we are now, and who knows what the Galapagos marine iguana, or the hagfish, or humans, look like in another few million years?

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