Tag Archives: research

New paper: Testing the stability of behavioural coping style across stress contexts in the Trinidadian guppy

My first empirical work from my postdoc with Alastair Wilson is out now in Functional Ecology (open access). We take a pretty deep dive into analysing individual variation in behavioural plasticity, including comparing multivariate among-individual behaviour across contexts, testing for a single underlying axis of variation, etc. The supplementary information also includes some R code showing how we did the main analyses, and the dataset is available on Dryad.

This paper also got a lot of traction in the popular press due to us showing that guppy ‘personality’ (i.e., consistent individual differences in behaviour) exists, is more complex than might have been thought, and persists across different stressors (which had large effects on the average behaviour in the population). Some of the articles are linked in my Media & Outreach page, and the video of my interview on BBC World News is embedded below.

 

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New paper: Food supply – not ‘live fast, die young’ mentality – makes male crickets chirpy

I have a new paper out in the journal Functional Ecology, entitled ‘Mating opportunities and energetic constraints drive variation in age-dependent sexual signalling‘. This is work from my PhD with Luc Bussière at Stirling, along with collaborators from the University of Exeter’s Cornwall campus (where I’m currently based).

We used dietary manipulations as well as manipulation of potential mate availability to investigate how male sexual signalling changes with current budget and previous expenditure. We found some cool results about what causes variation in age-dependent sexual signalling – these have implications for ‘honesty’ in sexual displays, and are also a nice reminder that there are simpler explanations than we (as humans, who love seeing patterns in the noise) often cling to.

Our paper also includes a nice example of using ‘zero-altered’ statistical models, enabling us to partition out effects on why males call from the effects on how long they call.

You can find the paper here, or email me for a PDF if you don’t have access to the journal.

Alternatively, the press office at Exeter put together a nice press release, which I’ve pasted below:


 

Shedding a few pounds might be a good strategy in the human dating game, but for crickets the opposite is true.

Well-fed male crickets make more noise and mate with more females than their hungry counterparts, according to research by the universities of Exeter and Stirling.

It has long been believed that males who acquire ample food can adopt a “live fast, die young” strategy – burning energy by calling to attract females as soon as they are able, at the expense of longevity – while rivals with poorer resource budgets take a “slow and steady” approach, enabling them to save resources and take advantage of their savings later in the season.

But the researchers found that increased diet – rather than any strategic decision by the cricket – led the best-provisioned crickets to chirp for longer. This had no noticeable cost to their lifespan.

Meanwhile hungrier males not only signalled less – meaning fewer female visitors – but also died younger.

Senior author Dr Luc Bussière, of the University of Stirling, said the findings offered a “simpler alternative” to understanding the behaviour of crickets.

“While it was intriguing to think that males might foresee and plan for their future reproductive prospects by strategically staying quiet, what our experiment suggests is actually easier to understand: rather than relying on an ability to forecast the future, crickets appear instead to respond mainly to the resources they have in hand,” he said.

Male crickets signal to females using an energetically expensive call, produced by rubbing together their hardened forewings.

The more time they spend calling, the more mates they attract.

The paper, published in Functional Ecology, studied decorated crickets, which mate about once a day on average during their month-long adult life.

Males need a three-hour recovery period following each mating to build a new sperm package, after which they are able to call again in the hopes of attracting another female.

Researchers found that a male cricket’s decision about whether to call was primarily based on whether females were nearby – rather than how well-fed they were – but the better-nourished males were able to call for longer and thus increase their mating prospects.

The study also provides insights into how energy budgets keep male displays honest for choosy females over the course of the mating season.

“In nature, a ‘better quality’ male will likely have better access to resources,” said lead author Dr Tom Houslay, a Postdoctoral Research Associate at the University of Exeter.

“Low-quality males might be able to ‘cheat’ by calling a lot one day, making females think they are high-quality, but this is not sustainable – so there is ‘honesty on average’.

“A female may be fooled once or twice, but over time males with more energy will call more – meaning females should tend to make the ‘correct’ decision by preferring those males.”

Applying the story circle to academic writing

Storytelling comes naturally to humans, but since we live in an unnatural world, we sometimes need a little help doing what we’d naturally do.

I’m a big fan of the work of Dan Harmon, writer of amazing tv shows like Community and Rick & Morty, and I’ve often heard him talk on his podcast (‘Harmontown’) about his ‘story circle’: a pattern to which most good stories conform.

The REAL structure of any good story is simply circular – a descent into the unknown and eventual return – and that any specific descriptions of that process are specific to you and your story.

The structure itself is pretty simple: a circle, divided and numbered as below, with each number representing a step on our journey.

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  1. When you
  2. have a need,
  3. you go somewhere,
  4. search for it,
  5. find it,
  6. take it,
  7. then return
  8. and change things.

 

It got me thinking about whether research papers fit this kind of pattern, whether they should, and also whether thinking about such a pattern when developing our papers would help structure them better.

“But my paper is about SERIOUS RESEARCH,” you might say. That may be so, but don’t you want your readers to also enjoy reading about it? If your paper isn’t compelling, then will it even leave a lasting impression?

I’ve taken most of this from Harmon’s notes on the Channel 101 page on story structure, and it’s worth going through that to see some more examples of how some of our favourite movies (ok, he mostly focuses on Die Hard) fit the pattern.

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Let’s go through the steps, and see how this structure might relate to the typical academic paper.

1. Establish a protagonist

Who is the protagonist in a research paper? This is – on the face of it – a tricky question, particularly as we are often taught to write in a weird passive (third-person?) voice, resulting in bizarrely disjointed sentences. The crusade against such an impersonal style includes things like the ‘by zombies’ meme, but still some people push it for reasons like ‘the focus should be on the results’, or ‘science should be impartial’. I agree, in that your research should not be carried out with an agenda. But you came up with the question, you designed the experiment, you carried it out, and you are presenting and interpreting the results. You are taking the reader on a journey with you. Don’t write yourself out of it.

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In fact, the context of a research paper means your reader instinctively knows who the protagonist is: a scientist, pluckily trying to advance their field. You don’t need to flesh it out any more than that. But you do have to establish the ‘zone of comfort’: the current state of research in your field. By bringing others into your zone at the beginning of the story, this is how your reader identifies with you.

2. Something ain’t quite right

Things aren’t perfect. They could be better.

Science in a nutshell. We could always understand things better than we currently do. Your job here is to show the reader what’s missing, what the gap in your knowledge is. This is your call to adventure.

3. Crossing the threshold

You are now entering an unfamiliar situation, because that’s what science is about: driving into uncharted territory, in search of something more. Harmon says here to figure out what your ‘movie poster’ is; that maybe doesn’t work as an analogy for scientists, as we have a tendency to front-load presentations of our research with the results. The threshold we are crossing here is between defining our knowledge gap, and attempting to rectify that gap with further research. Our movie poster is not the results, but the question.

4. The road of trials

Is there a more fitting descriptor for a methods section? Harmon talks here of how, in ‘Hero with a Thousand Faces’, Joseph Campbell “evokes the image of a digestive tract, breaking the hero down, divesting him of neuroses, stripping him of fear and desire”. You’ve crossed the threshold, the adventure has begun; “our protagonist has been thrown into the water and now it’s sink or swim”.

Your reader needs to know the tools with which you are going to approach your call to adventure, and they need to know this as quickly and efficiently as possible.

The purpose here has become refreshingly – and frighteningly – simple.

5. Meeting with the goddess

This is a time for major revelations, and total vulnerability

…In other words, the results of your research. What did you find? Don’t be afraid to say, we found nothing – particularly if your trials were designed well enough that you can say that conclusively.

To paraphrase Harmon’s words here: we started from a position of safety and comfort (1), but a lack of completion (2) drew us to a question (3) and we were pulled across a threshold into the unknown. Via our experiment, our understanding was transformed (4) by gaining this new, hitherto-unknown knowledge (5). Show it with a definable moment, advises Harmon. Clear, understandable figures and tables bring the reader with you in these revelations.

On the circle, this is the opposite of the protagonist’s zone of comfort; movement beyond this point requires you to push forward. Figuring out the question, and performing the experiment, was almost the easy part compared to what comes next…

storystructure.jpg

6. Meet your maker

This half of the circle has its own road of trials – the road back up. The one down prepares you for the bed of the goddess and the one up prepares you to rejoin the ordinary world.

I like the description Harmon gives in a later page:

The hardest part (both for the characters and for anyone trying to describe it). On one hand, the price of the journey. The shark eats the boat. Jesus is crucified. The nice old man has a stroke. On the other hand, a goal achieved that we never even knew we had. The shark now has an oxygen tank in his mouth. Jesus is dead- oh, I get it, flesh doesn’t matter. The nice old man had a stroke, but before he died, he wanted you to take this belt buckle. Now go win that rodeo.

With the results in hand, you now have to do the hardest part: interpret what they mean. The ‘heavy price’ we pay as scientists is that sometimes we don’t find what we expect, and things are often messy, and complicated, and hard, and we have to think about them a lot. Again, look at the opposite side of the circle, which was the call to adventure (2). You identified a knowledge gap, and now you need to consider what your results mean in that context – and bring your readers with you.

Now, instead of reacting to the forces of the current state of research – “adapting, changing, seeking” – you have BECOME the current state of research. You are the cutting edge.

You have become that which makes things happen. You have become a living God.

(So I guess this is about where you start fantasising about submitting to Nature)

7. Bringing it home

It’s not a journey if you never come back.

The return to the familiar situation – we can now come back to the beginning of the story, the state of research as we left it, armed with the new knowledge gleaned on our journey.

8. Master of both worlds

The protagonist, on whatever scale, is now a world-altering ninja. They have been to the strange place, they have adapted to it, they have discovered true power and now they are back where they started, forever changed and forever capable of creating change. In a love story, they are able to love. In a Kung Fu story, they’re able to Kung all of the Fu. In a slasher film, they can now slash the slasher.

…And in a science paper, you can now science the science. How are you capable of all this? Because of what happened before – just look at the opposite side of the circle. The opposite of (8) is (4), the road of trials. You did a science, and now you can science some more. Show your reader what you’ve done. The state of research in your field is forever changed, because of your journey. A hero’s journey.

 

To finish, Harmon provides an example of breaking down the structure using The Matrix: the story of an everyday guy (1) that gets a weird call (2) and, upon following it, realizes that reality was an illusion (3). He learns the ropes (4), talks to the oracle (5), loses his mentor (6), goes back (7) and saves the fucking day (8). Can we apply this kind of structure to our favourite science papers?

Andersson (1982) Nature

Malte Andersson believed Darwin’s hypothesis about the evolution of male sexual ornaments through female preferences was plausible (1), but saw little experimental evidence that such preferences exist (2). Would experimental increase of ornaments confer higher mating success (3)? He manipulated widowbird tail length (4), found males with elongated tails won more mates than those with shortened or ‘control’ tails (5), and excluded other variables to conclude that changes in tail length caused the differences in attraction (6). His results supported Darwin’s hypothesis that certain male ornaments are favoured by female mate choice (7), and probably evolved through it (8).

Not as snappy as the Matrix, sure – but Andersson’s journey changed the idea of sexual selection as ‘plausible with no great evidence’ to ‘plausible with some solid evidence’. A basis for further journeys. For more heroes to come.

Will knowing this structure make you a great writer? No. To return to a quote from earlier:

The REAL structure of any good story is simply circular – a descent into the unknown and eventual return – and that any specific descriptions of that process are specific to you and your story.

You still need a story to tell. But this might just help you figure out how to tell it.

 

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Quotes all taken from Harmon’s ‘Story Structure‘ posts on the Channel 101 wiki.

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Update: Through the delights of twitter, I just found that Ian Lunt has a video online of a talk he gave on using this approach for science communication, called ‘Shaping stories to save the world‘. I highly recommend watching this, particularly as Ian discusses the difference between the circle and the ‘hourglass’ approach to telling a story. It comes to mind that the story circle may be better suited to seminars and popular writing than it is to research papers – something to think more about, anyway…

New paper, new job, stuff like that

Things have been pretty slow on the updating side (yet again), but I have been busy with THINGS and also STUFF!

I have just had my first research paper (snappily titled ‘Sex differences in the effects of juvenile and adult diet on age-dependent reproductive effort‘) from my PhD published, in the Journal of Evolutionary Biology. Happily, the review process was really great – the editor (Thomas Flatt) was really helpful, and we had great, constructive reviews from Sue Bertram and Mike Kasumovic (who did sign their reviews, I’m not just outing them!).

 

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In the paper, we manipulated resource acquisition at both the juvenile and adult stage in male and female crickets, and tracked allocation to age-dependent reproductive effort. Crickets are great for this kind of work, as reproductive effort is easy to quantify for both males and females (not the case in a great many organisms): fecundity (i.e., egg production) in females, and sexual signalling (time spent calling) in males. We investigated how resource acquisition affects allocation to reproductive effort over time, and also how this affects investment in longevity… Not only did we find some interesting results, but I also got to showcase the use of Zero-Altered Poisson (ZAP) models for male signalling! This is a really useful type of statistical analysis, as we can look at two factors within a single model:

  • What factors affect whether a male calls or not (binary ‘0/1’ response)?
  • Given that a male does call (i.e., a ‘1’ in the first part of the model), what factors affect how much he calls?

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I’m currently working on a manuscript which will delve a little deeper into questions of male signalling, using ZAP models but also a pretty cool experimental design that I think has given us some really interesting results (let’s hope the reviewers agree!). I’ll also be talking about this work at the European Society of Evolutionary Biology (ESEB) conference in Lausanne this August (so hopefully I can get it submitted for publication soon!).

The other big news is that I have finally secured a new research position! I have joined Alastair Wilson’s group at the University of Exeter’s Penryn campus, and my postdoc will focus on the evolution of stress response. This will entail lots of behavioural work and measuring hormones, as well as some pretty intense stats and quantitative genetics! Also, I’m having to learn about vertebrates, as the study system will be guppies… but don’t worry, I’ll still be tweeting / going on about weird insect sex as much as possible. Everyone’s got to have a hobby.

Other stuff: I’ve had a couple of photos published in scientific journals, which happen to also be really cool papers so worth reading (see links below)! I am also working on a setup to get some good guppy photos ready for my own future talks / papers.

Burying beetle in Schrader et al’s work on using experimental evolution to study adaptations for family life (American Naturalist).

Wasp in Rojas et al’s primer on aposematism (Current Biology).

A victory for invertebrates!

Last Saturday saw myself and some other Stirling-based researchers brave the resurgent snow to travel across to St. Andrews University for 2011’s Scottish Conference of Animal Behaviour (SCAB). This was a really great meeting, being small but still covering a variety of fields – my university was represented not only by attendees from ecology and evolutionary biology, but also from the psychology department, some of whom work in conjunction with the Living Links research station at Edinburgh Zoo.

The talks were all of a very high standard, and I had to prevent myself from exploding in a fit of jealous rage at some of the research being undertaken. Thibaud Gruber kicked things off in this vein, showing some fantastic videos of chimps singularly failing to learn how to use sticks to get at honey he’d secreted in holes in logs. My personal favourite was the experiment in which he actually placed the stick into the hole, only for a chimp to remove it, lick the honey from it, and then throw the stick away in favour of scrabbling around with its fingers and rolled-up leaves. As with all research, the combination of excitement and frustration was palpable…

2001 ape

Bonus video – chimps using sticks to ‘fish’ for termites:

Paris Veltsos of St Andrews gave a talk that was of great interest to me, discussing courtship song and cuticular hydrocarbons (CHCs) in populations of Drosophila montana. Veltsos and his collaborators found that various factors outside simply courtship effort contribute to net selection on song; they also saw differences in CHC selection between the two populations. I had a quick chat with Paris after the end of the meeting, and am looking forward to reading the paper that comes from this work (which I shall then review here).

There were also excellent talks on fish, including one which resulted in the lecturer driving us back to Stirling devising a project that should enable him to sit and watch the Tour de France all summer as ‘research’; another from the University of Glasgow’s Amy Schwartz, on sexual selection in guppies, made tantalising references to ‘Nature’s Laboratory’ in Trinidad. I bit my knuckles as I thought of the stark walls of my two controlled temperature labs. Perhaps I should put some posters up in there.

While I remained under no illusions as to the lack of romance in the laboratory setting of my work, I was clinging to the last vestiges of my pride by thinking, well, my crickets are kinda cute…

…and then came the presentations based on work using the rufous hummingbird.

I’m not sure even the most charismatic of my cricket hordes can really compete with that.

Still, there was to be a final sting in the tail – my friend Ros Murray, also working in the sexual selection lab at Stirling, won the prize for best student presentation. This was no mean feat, considering both the standard of the talks on show and the fact that she was discussing her work on sperm competition in the microscopic nematode worm Caenorhabditis elegans. It was a great talk, and covered some really elegant work that included the use of GFP (green flourescent protein) as a marker that was passed to the next generation by the ‘winning’ sire, clearly indicating to which of the competing males the offspring belonged. The award also comes after finding that this work has been accepted for publication in BMC Evolution journal, which is really excellent news. She probably deserves the reward after the mockery she’d put up with from some of us over her tiny, tiny worm sperm going head-to-head with monkeys and hummingbirds…