Natural history: out of fashion and out of time?

To my fellow natural history students/natural historians: I’m sorry, but we’re not cool anymore. Yes I know that we think we’re cool because we alone know the truth, that we are cool. But no one else in the science world thinks we’re cool even though the stuff we study is just as cool as the cool stuff  anyone else studies. But if every thing that scientists study is cool then suddenly the playing field is level again and we’re back to having our coolness defined by other people’s perceptions. And I’m sorry to say that they tend to think that we focus a little too much on how things have sex.

Most whole organism biologists I know don’t even call themselves ‘naturalists’. It’s a little too close to ‘naturist’ and has airy fairy, non-intellectual connotations. Then, when a visiting mite scientist from Alberta makes an offhand comment about how little natural history is practised nowadays, it seems a natural state of affairs even if it’s not apparent why it should be. Then, at least once a year in my university life, I’ve been asked ‘when are you going to change to a real degree?’ or ‘does this have any commercial application’? In order to see how natural history became a slightly embarrassing branch of academia with little societal ‘value’ and how the field has actually started shrinking, apparently without our notice, one has to take a look at the pursuit’s history which saw it see-saw in and out of vogue.

Now, ‘natural history’ is a slippery concept. ‘Natural’ is easy enough: animals, plants, geography, geology, plus chemistry (back before physics invaded it). Then a ‘history’, back when the term was first coined, meant more of a description or a systematic account (Herman, 2002). Therefore, natural history is a descriptive and analytical science tasked with providing a systematic account of the natural world be it biological, chemical or geological .

240px-Carl_von_Linné
Carl (1707-1778)

Natural history has ancient origins –Aristotle level ancient (Llana, 2000). But it’s modern heyday probably began in the 1700s with the discovery of new flora and fauna in the New World. The printing press provided the means to accumulate and disseminate information quickly and, consequently, scientists were flooded with information from around the world and forced to create systems and diagrams simply to deal with the information overload. This epoch generated the taxonomic work of Swede Carl Linnaeus as well as a wealth of texts by others including the famed Encyclopédie, a significant Enlightenment era work published in France in which natural history – particularly botany – featured heavily (Llana, 2000; Müller-Willer & Charmantier, 2012).

By comparison, the world of natural history is a lot quieter now. There is even concern that it will go extinct altogether (Wilcove & Eisner, 2000). As early as the beginning of the twentieth century, key scientists had already side-lined natural history as an amateur’s pursuit in their unwavering adherence to Karl Popper’s ruling that, in order to be a true capital-‘S’ Science, a field’s theories must

220px-Karl_Popper
K-Pop (1902-1994)

be falsifiable. Natural history, which generates qualitative descriptions, does not quality (Schmidly, 2005). Even though Popper’s emphasis on falsification has been shown to be limited and overly simplistic historically, a distrust of inferential and descriptive analysis persists (Chalmers, 1999). Furthermore, with the pressure during World War II and the Cold War to fund science which generates ‘results’ (Pyle, 2001); a persistent focus on medical sciences; the growth of urban populations producing generations with little experience in the ‘natural’ world (Weigl, 2009); and a degree of technophilia with the rise of molecular biology  (Schmidly, 2005), it’s easy to see why ‘faddism’ developed in universities. In short, the big biology bandwagon is parked outside molecular science’s door.

Consequently, many American natural history departments are down-sizing as the number of students who have interest in the natural world decreases and as universities scramble for funding which inevitably goes towards sure-fire, rapidly generated, high impact publications (i.e. non-ecological studies). Many natural history courses are discontinued after the co-ordinating professor leaves and some departments sell their natural history collections (Schmidly, 2005).

The effects are less keenly felt in New Zealand because, more so than in other places, experience with and respect for the natural environment is coded into our national identity (whether we really deserve this ‘greenie’ image is another matter altogether). Beach-goers are still treated to orcas in the harbour and if you’re lucky then a kereru he size of a rugby ball will alight on your puriri tree with all the grace of a small helicopter. That is to say nothing of our dependence on primary industries.

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Yet the gloom’s starting to gain traction here. When people ask ‘Oh animal biology? So not real science then?’, that’s the internalised, 100-year old notion of natural history as an irrelevant science talking. But I still think ‘extinction’ is a little dire. After all:

1)       Our ever expanding world still has unknown frontiers which require analysis whether it be the surface of Mars or the deep sea. Where ever there are new species being discovered or borders being extended, there is a need for the descriptive quality of natural history. After all, for many years, the first issues of the Transactions and Proceedings of the Royal Society of New Zealand, begun in 1868, were wholly dominated by natural history as settler-scientists began to roam about exploring the country.

2)       In addition, the naturalists’ deep abiding enthusiasm for the world has historically made them successful communicators to the public and this tradition continues today with the likes of David Attenborough (Schmidt, 1946) and this success

3)       Inspires amateurs to continue the practice.

4)       Furthermore, due to relatively low operating costs (like, the cost of a ruler, a pencil and petrol), natural history is an ideal field for developing universities or developing nations to establish academic profiles within (Schmidly, 2005).

5)       Finally, natural history’s extinction has been predicted before but it made like a species and adapted.

What I’m referring to is remediation of the ‘dichotomy’ between naturalists and experimentalists at the beginning of the twentieth century. As the split widened, scientific leaders called for a ‘synthesis of purpose and aims’ (Allen, 1979). The result was ‘Modern Synthesis’ which argues that all evolutionary phenomena can be explained in genetic terms which are consistent with observations by naturalists (Mayr, 2004). This theory is hailed by biologists and science historians as the ‘primary integrative event’ of twentieth century biology (Schmidly, 2005).

So while natural history is certainly not the hotshot of the science playground at the moment, an understanding of the pursuit’s history emphasises that its wane in estimation is the product of historical shifts in priorities and an adherence to debatable yet persistent science philosophies. This state of affairs may cause funding headaches and make employment difficult for people – which is bad – but we’re not witnessing a protracted extinction because it would be foolish to think that we have so completely explored our world to make natural history wholly redundant. At the very least, natural history imbues the world with detail and majesty. People like that.

References (APA)

Allen, G.E. (1979). Naturalists and experimentalists: the genotype and the phenotype. Studies in the History of Biology, 3, 179-209.

Chalmers, A.F. (1999). What is this thing called Science? United Kingdom: Open University Press.

Herman, S.G. (2002). Wildlife biology and natural history: time for a reunion. Journal of wildlife management, 66, 933-946.

Llana, J. (2000). Natural history and the “Encyclopédie”. Journal of the History of Biology, 33(1), 1-25.

Mayr, E. (2004). What makes biology unique? Cambridge, United Kingdom: Cambridge University Press.

Müller-Willer, S. & Charmantier, I. (2012). Natural history and information overload: The case of Linnaeus. Studies in History and Philosophy of Biological and Biomedical sciences, 43, 4-15.

Pyle, R.M. (2001). The rise and fall of natural history, Orion Autumn 2001, 16-23.

Schmidly, D.J. (2005). What it means to be a naturalist and the future of natural history at American universities. Journal of Mammology, 86(3), 449-456.

Schmidt, K.P. (1946). The new systematics, the new anatomy, and the new natural history. Copeia 1946, 57-63.

Weigl, P.D. (2009). The Natural History Conundrum Revisited: Mammalogy Begins at Home. Journal of Mammalogy, 90(2), 265-269.

Wilcove, D.S. & Eisner, T. (2000). The impending extinction of natural history. Chronicle of Higher Education,

47(3), B24.

Mantises eating mantises to make mantises

So last time was wining and dining with insect people. This time it’s back to dining *hur hur*.

*Hem*

To recap on sexual conflict: it happens whenever the optimal reproductive strategy (i.e. means of maximising one’s reproductive output) of one sex encroaches on that of the opposite sex and this happens because eggs are like elephants and sperm are more like ants – there are a helluva lot more of the latter but the former are a helluva lot bigger. (The analogy ends there. I wouldn’t want to suggest that eggs are scared of sperm like elephants and ants are…).

So while sexual conflict reflects a common inequality in gamete size/availability across many sexually reproducing species, the way that this conflict manifests varies significantly. One such way is through the development of clasping behaviours and structures in male water striders as I discussed in my first post with these structures helping males defend their ladies against any hopeful rakes. Another such way is through sexual cannibalism.

Would it be a surprise to anyone if I said that I was never met with glazed eyes whenever my research came up? Mild disgust, yes. Morbid fascination, sometimes. ‘Does that have any commercial applications?’, you’d be surprised. Most commonly, ‘Pardon?’ (Read: ‘I had only asked because I was being polite so I was only half listening but if I heard correctly then this conversation has taken a turn for the surprising. Let me charge your glass so you might tell me more of kinky insect noms’.)

This is what sexual cannibalism is according to the internet (with safe search on):

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I don’t want to go into all the reasons sexual cannibalism makes such good nightmare fodder in erotic horror fiction and also don’t want to go into all the consequences that this interest has for the study of sexually cannibalistic species. There is an ongoing debate about this which has reached the internet already. I might go into detail one day but not now.

Instead the point I want to make is that the reason why sexual cannibalism is such an interesting behaviour in a biological context. The simple reason is that the sex enforcing this extreme behaviour are females rather than males. The previous example of male water striders clinging to resistant females is a much more common pattern while in the case of sexual cannibalism, females are very much the ones enforcing the costs.

It can be hard to reconcile how a behaviour which kills a member of one’s own species could possibly be maintained or even be developed in the first place and there are a number of conflicting hypotheses as to how cannibalism can be maintained. The main one I want to look at is called the ‘Adaptive foraging hypothesis’ which was central to my study of the springbok mantis, Miomantis caffra. This hypothesis suggests that sexual cannibalism is a foraging strategy employed by females in times of food limitation and it entails a subset of hypotheses about how this behaviour will manifest. (Aggressive spillover is another major contending set of hypotheses (2)).

To understand how sexually cannibalistic could prove an advantageous hunting strategy you have to remember how spiders and praying mantises live. Both species are cryptic sit-and-wait predators. Spiders generally hide in cracks or in corners while mantises are generally very well camouflaged to their environments and neither will tend to move unless disturbed. The advantage of this is that they can avoid detection by predators and potential prey. Hence they ‘sit-and-wait’. The downside of this strategy is that, if there aren’t many flies around that season, then there’s not a lot that they can do about it.

But female spiders and mantids have a way around this. Females of both species emit long distance sex pheromones from their bodies or, in the case of spiders, from their silk. These airborne chemicals (Chanel/Dior etc.) are detected by males who race to reach the female and mate with her. So, if food is scarce and females are particularly hungry, it only makes sense to ‘make use’ of the males who turn up of their own volition.

And a female consuming males due to low availability of food isn’t just about ensuring that the female doesn’t starve. It seems that female body condition (think of it as an arthropod BMI) can be strongly related to the number of eggs that female can produce aka her ‘fecundity’. She’s not just hungry. She’s not eating for two so much as 401.

Now there is a complication. There are two ways that sexual cannibalism can manifest and the difference is vitally important to understanding the costs and benefits of the behaviour. It’s all very technical but bear with me and we can take a break if it gets a little too complicated. Basically, sexual cannibalism can occur:

  • before sex…
  • or after (slash during).

Phew, made it. The former is called ‘non-‘ or ‘pre-copulatory cannibalism’ while the latter is called ‘post-copulatory’ or just ‘copulatory cannibalism’.  Now, with post-cop cannibalism, females get to mate AND eat which raises the question of why any female would bother with pre-cop cannibalism. Furthermore, if a female eats every male that turns up without mating then she runs the risk of never getting the chance to mate before the seasons change (assume winter = death). So it’s a little hard to see why not all sexually cannibalistic species just eat the male after mating.

There a couple of potential reasons for this. Firstly, males might be in a better position to escape after mating. Secondly, mating can take a long, long time. Some mantises mate for around seven hours and female condition gets appreciably worse throughout the ordeal. Consequently, sometimes it’s a case of a meal now versus the chance of a meal later. However, the pressure to mate is high so it is expected under the Adaptive foraging hypothesis that females would be less likely to cannibalise males as time goes on and the prospect of a frosty death begins to loom.

Costs and benefits
Pros and cons of cannibalism without mating (according to the Adaptive foraging hypothesis)

Basically, there are two major primary ecological constraints which can support the development of sexual cannibalism: food availability and mate availability. If you have a small number of food species around but a surplus of potential suitors, sexual cannibalism is a valuable asset for a female. In my own work I mainly looked at the availability of food and how that influenced the frequency of sexual cannibalism. In the wild this is generally the result of major environmental changes which influence the availability of prey. In the lab it involves with-holding locusts from a lab population. Science!

Next time: I need to take a break from mantises. I’m sure an equally dignified topic will present itself.

References:

  1. The Adaptive foraging hypothesis was formally described by Newman and Elgar in 1991 and entails five different hypotheses. Based on work with the fishing spider Dolomedes sp.

    dolomedes-triton080617-5066sandycrkz
    Dolomedes dawwwww
  2. The Aggressive spillover hypothesis was generated when Arnqvist and Henriksson found that the Adaptive foraging hypothesis didn’t fit with their own experimental spider species. It suggests that the level of female aggression is determined during development and that aggressive female nymphs (young) are more likely to survive into adulthood as they’re more voracious feeders. As adults they continue to be aggressive to anything that comes near them, including males. Under this hypothesis, sexual cannibalism is maladaptive i.e. not advantageous and is merely the by-product of the survival of more aggressive young.

Oh yeah, pictures:

This is wrong
This is wrong
This is right.
This is right.

Weta and wine; thoughts on the NZ Entomology Conference 2013

Introduction

I’d would like to interrupt our regularly scheduled program (haha what?) to talk about the conference I went to last week. From what I can understand, scientific conferences are a means of disseminating information about new protocols, new fields of research and providing a platform for industry representatives to explain new initiatives and outline any restructuring that government departments may be going through. For smaller conferences such as this one, they’re also a good opportunity for graduates to present their work in an academic environment and to meet with potential supervisors.

My only previous scientific conference experience was one day at the Entomological Society of New Zealand (ESNZ from now on) conference in 2012 and posts on whatshouldwecallgradschool.tumblr.com. From my experiences with the latter, I went in expecting terrified students and free comfort food.

I went with the purpose of presenting my honours project from last year because apparently that’s what grown up academics do and because it’s also good practice learning how to condense a year’s worth of anxiety and biology into a ten minute talk and powerpoint presentation. Having said that, there probably isn’t much left once you’ve trimmed out the anxiety part. On one hand, my performance would have no impact on any grades and there would be no written record of assessment. On the other hand, I would also be presenting to a room of people who have no personal investment in my success and who could tear me to pieces with impunity and with no fear of having to see me skulking like a wounded spaniel around their office the next week.

Methods and materials:

This survey was conducted at Massey University in Palmerston North, New Zealand from the 2nd – 6th of April. There were 57 registered attendees, the lowest it’s been for the last couple of years. Our Auckland contingent consisted of 11 people.

If you haven’t been to a conference before, this is generally how things seem to work.

  1. Listen to a 12 minute talk followed by 3 minute question time. Repeat four to five times.
  2. Leave lecture theatre to forage for biscuits and tea. (For the brave, accost the interesting speaker/potential supervisor or employer during this period. If you are hung-over from conference dinner or are recovering from gastro, go find the UoA students because they’ve probably found a quiet nook to hide in and talk about how scary it all is.)
  3. Lady at reception walks around the group ringing a bell to herd the sheeple back into the lecture theatre (Remember that my conference sample size is n = 1.3).
  4. Rinse and repeat.

As well as the talks during the day, the cost of registration usually also entails a conference dinner during which students, industry and academics can meet in a neutral location and have the rusted wheels of human conversation greased by an ad libitum application of wine and tapas.

Results:

There were 42 talks at the conference and the break-down of the nature of these talks is shown in Fig. 1. Meanwhile, Fig. 2 shows the distribution of topics for the conference, namely what proportion of talks each day was about weta. The largest number of weta talks occurred on the first day and to be quite frank 7/16 talks on weta is just a bit too many dammit. All weta talks were presented by students at Massey University which, unsurprisingly, was the most strongly represented academic institution present at the conference (Fig. 3). The fact that other North Island Universities had the second largest contingents pretty strongly indicates that students are poor and that people hate travelling long distances although the last part might just be me.

Fig.1: Break-down of talks depending on who they were coming from.
Fig.1: Break-down of talks depending on who they were coming from.
Fig. 2: Of those talks associated with a university (i.e. by students and their supervisors), the university of origin for those talks.
Fig. 2: Of those talks associated with a university (i.e. by students and their supervisors), the university of origin for those talks.

 

Fig. 3: Too many.
Fig. 3: Too many.

While I have no numerical data on this I did observe that the University of Auckland table at the conference dinner was somewhat magnetic (Fig.4) . At t = 0, bottles of Matua valley private bin were roughly equally distributed around all the tables. By t = 5 hrs, many more of them were at the Auckland table and these accumulated despite displacement of some UoA members to other tables.

Fig. 4: EntoSoc Conference dinner arrangement at the start of the evening (t = 0) and at the end (t = 5) Roma’s showing number of seated attendees (n), and distribution of red wine. (White wine not shown because it would probably be too sad).
Fig. 4: EntoSoc Conference dinner arrangement at the start of the evening (t = 0) and at the end (t = 5) Roma’s showing number of seated attendees (n), and distribution of red wine. (White wine not shown because it would probably be too sad).

This is merely observational so I am unable to draw any conclusions from this event. However, I did learn that the operative word for Matua Valley Private Bin wine is ‘BIN’.

Discussion:

My general assessment of this particular conference for this year was that, due to its small size, it was an ideal platform for students as a large number of speakers a large proportion of the attendees were students and their supervisors. As entomology covers a wide range of disciplines (phylogeography, behavioural biology, molecular ecology, natural history etc. etc.) there is perhaps less to be gained for those looking for new and exciting ways to conduct their own research rather it’s a means for supervisors and graduates investigating other research options to scout out what is being studied in other academic institutions (go to Massey, they have weta).

Conclusions:

Beat poetry is the way to go for my next conference talk.

It’s about sexual conflict and it’s about time

I had wanted to talk about something else for my first blog post because talking about the background to my own work seems a bit indulgent. But first semester has already rolled around and I still haven’t posted anything. More importantly, the Entomological Society of New Zealand conference is coming up after Easter and I’ve told enough people that I’m going to present that I’m now obliged to submit an abstract. The last time I looked at my dissertation I was swaddled in a giraffe suit and hooked up to a tea IV drip.

So, if nothing else, researching for this post is a good way for me to remind myself about what the hell my dissertation was all about and shoe horn it back into my brain in time for the abstract submission on the 16th (been and past. Status: Accepted. Holla.)

By the way, my dissertation was about sexual cannibalism in praying mantises. But as exciting and bizarre as sexual cannibalism sounds, it’s only one of a spectrum of…unpleasantness between the sexes.

To take humans as a familiar example. It hardly needs saying that interactions between men and women throughout the world are fraught with direct conflict, misunderstandings and incompatibility of expectations. Women want ‘the one’ while men supposedly want ‘one right now’. It’s cliché to state it plainly but these tropes do have a basis in biological fact (whether they should be enforced in media is another kettle of fish.) Anisogamy is the phenomenon in which the gametes, the bodies that carry a parent’s genetic contribution to a child (i.e. female eggs and male sperm), differ in size between the sexes. Females provide a much larger, well provisioned gamete but producing only a small total in their life-times. Eventually, women reach menopause which heralds the end of any reproductive behaviour.

Meanwhile sperm, relative to eggs, are tiny. But while they may be tiny, they

So meta
So meta

are also produced at a rate of 1,500 spermatozoa per second and men will continue to produce sperm well into their twilight years, long after their female counterparts have lost any reproductive capacity. So on an individual, national, global scale, the number of women’s eggs is minute relative to the number of available sperm. In short, ova are a limited resource.

This pattern of ova paucity and sperm surplus holds in the majority of animals, not just humans, and the consequence of this is that it is in a female’s interest to be choosy about who she mates with in order to ‘make the most’ of her limited number of offspring. Males, meanwhile, have no such limit and therefore tend to improve their ‘reproductive fitness’ by fertilising as many eggs as possible with his veritable bounty of sperm. This disjunction of ‘optimal strategies’ for males and females generates ‘sexual conflict’(1). This could be that males are more inclined to copulate with as many females as possible whether those female’s want to or not.

And you can see how such conflict arises. A surplus of sperm relative to the number of eggs means that it is therefore advantageous for males, overtime, to develop behaviours or structures to force copulation on females and, in response should these behaviours become prevalent, becomes advantageous for females to develop behaviours and structures which help her to evade male ‘affections’.

The humble Gerris incognitus
The humble Gerris incognitus

Possibly one of the simplest and best understood examples of this is the that of the humble water strider (2). To state it simply, male water striders cling to a female’s back and develop genital clasping structures to hold on to the struggling female beneath him. Females are not only forced to copulate but they’re also forced to carry the male around on her back. If this male behaviour becomes common, it becomes advantageous for females to kick males off their backs and to develop uncomfortable looking spines on their abdomens to discourage their suitors from holding on too long.

Water striders are just one example of sexual conflict and manifestations of this conflict are extremely common throughout the animal kingdom. What differs is the extent to which this conflict has become exaggerated. The water striders example with its repeated to-ing and fro-ing of behaviours and structural changes has granted that particular system the descriptor of ‘sexually antagonistic coevolution’. Coevolution refers to when groups evolve with respect to each other rather than due to selective pressures enforced by their environment. The development of close knit relationships between certain flower and bee species is a good example of a mutually beneficial form of coevolution. SAC is obviously a little less congenial.

From 'Franken fran  by Katsuhisa Kigitsu. Censored by moi.
From ‘Franken fran
by Katsuhisa Kigitsu. Censored by moi.

So next time: Mantises eating mantises to make more mantises.

References:

1)       The concept of sexual conflict was first formally described and related to anisogamy by Parker in 1979 in his seminal work, ‘Sexual selection and sexual conflict’, a chapter within Sexual selection and reproductive competition in insects, which was edited by Murray and Nancy Blum.

2)       The understanding of the sexually antagonistic coevolution within the water strider species Gerris incognitus has been developed over the last two decades with some of the most important papers being published by Arnqvist and Rowe in 1995 and in 2002.