Wallace, Darwin and the night shift

Last week I had the great honour of attending the Royal Entomological Society’s annual conference, this year hosted by Edge Hill University, to accept the 2017 Alfred Russel Wallace Award. The award is given for the PhD thesis “judged to make the most significant contribution to entomology in the year”, and after several rounds of selection my own thesis, “The role of moths as pollinators, and the effects of environmental change”, was chosen. At the conference, I said that I was particularly proud to receive an award in Wallace’s name, because of his own connections to the subject matter of my thesis – nocturnal pollination by moths. In this blog, I re-tell the story of that connection…

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It is 25th January, 1862, and Charles Darwin is writing to his friend and confidante Joseph Dalton Hooker. Earlier that same day, Darwin had taken delivery of a box of specimens of exotic orchids from James Bateman, a Staffordshire-based orchid specialist.1 Among these, Darwin found one in particular (Angraecum sesquipedale, a species from Madagascar) to be remarkable, due to the great length of the nectary, extending 11.5 inches below the flower. “Good Heavens”, wrote Darwin, “what insect can suck it”.

Angraecum_sesquipedale.png
(L-R) a drawing of Angraecum sesquipedale by W.H. Fitch, included in: James Bateman (1876) A second century of orchidaceous plants. Curtis’s Botanical Magazine; two flowers of A. sesquipedale (© Michael Wolf | Wikimedia Commons | CC BY-SA 3.0); a plate commissioned by A.R. Wallace depicting the hypothetical hawkmoth pollinator of A. sesquipedale, drawn by T.W. Wood and included in: Alfred Russel Wallace (1867) Creation by Law. The Quarterly Journal of Science, 477.

Darwin must have acted quickly. In the same letter to Hooker he had described his “infinite satisfaction” at the prospect of correcting the proofs of his next books, Fertilisation of Orchids, “in 2 or 3 weeks”. Yet when Orchids emerged less than four months later on 15th May, Darwin had revised the text, incorporating a discussion of A. sesquipedale and a rough hypothesis as to its insect pollinator. Reasoning that the longest tongues among English insects belonged to hawkmoths (family Sphingidae), he wrote:

in Madagascar there must be moths with probosces [sic] capable of extension to a length of between ten and eleven inches

Darwin’s prediction sparked debate; among those who sprung to his defence was Alfred Russel Wallace. Contrary to popular opinion, correspondence between Darwin and Wallace was friendly and reasonably frequent after they jointly proposed evolution by natural selection (van Wyhe & Rookmaaker 2015). Five years after the publication of Orchids, Wallace’s Creation by Law asserted not only that Darwin’s predicted moth could safely be assumed to exist, but further, that naturalists visiting Madagascar “should search for it with as much confidence as astronomers searched for the planet Neptune”. Wallace picked out one moth in particular to back up this statement – Xanthopan morganii, then known from tropical Africa (as Macrosila morganii), which had an exceptionally long proboscis.

Xanthopan_morgani.png
Xanthopan morgani; a specimen from continental Africa. Malagasy X. m. praedicta have proboscides several inches longer still!

Several decades later, Walter Rothschild (2nd Baron Rothschild) and Karl Jordan described a newly-discovered subspecies of X. morganii, from Madagascar. Remarkably, the subspecies had a tongue that was, by several inches, longer than that of its continental cousins. In honour of the predictions made by first Darwin and later Wallace, the new subspecies was named X. morganii praedicta.

DarwinWallaceRothschild
(L-R) Charles Darwin, Alfred Russel Wallace, and Walter Rothschild

At this point, the trail went cold for the best part of the 20th century. We had the flower, and we had found the moth with a proboscis to match it, but the final proof of their association was lacking because nobody had ever seen the two interact. That state of affairs lasted until the early 1990s, when Professor L.T. Wasserthal (then of the Friedrich-Alexander University Erlangen-Nuremburg) finally photographed, beyond doubt, the pollinator of A. sesquipedale. It was, indeed, X. morgani.

BotanicaActa
Making the front cover, a photograph of Xanthopan morgani praedicta visiting the flower of Angraecum sesquipedale finally resolves the mystery!

As a final chapter, the video below is well worth a watch: both for its remarkable footage, shot in 2004 by Dr Philip DeVries of the University of New Orleans, of this pollination interaction in action, and for the sheer joy and excitement shown by Dr DeVries and his colleagues when their hard work finally paid off!

If you want to learn more about this story, I owe a debt of gratitude to the review of Arditti and colleagues (2012), on which I drew heavily whilst researching this blog.

1: The relationship between Darwin and Bateman must have been complex. Bateman was, at this time, one of Britain’s foremost experts on, and cultivators of, orchids, and it is hard not to assume that he and Darwin corresponded while the latter prepared Fertilisation of Orchids. However, this box of specimens, and a brief subsequent exchange of letters, appears to be the only surviving evidence of direct interaction between the two (Darwin Correspondence Project). Bateman lived at Biddulph Grange in Staffordshire, designing (with his wife Maria) its famous landscape gardens, which are now owned by the National Trust. The gardens featured a Geological Gallery, seen as a direct attempt to refute Darwin’s theory of evolution by natural selection by drawing connections between evidence from the fossil record and the account of creation given in the book of Genesis.

References

Arditti, J., Elliot, J., Kitching, I.J. & Wasserthal, L.T. (2012) ‘Good Heavens what insect can suck it’–Charles Darwin, Angraecum sesquipedale and Xanthopan morganii praedicta. Botanical Journal of the Linnean Society169, 403-432.

Darwin Correspondence Project, “Letter no. 3356,” accessed on 3 April 2018, http://www.darwinproject.ac.uk/DCP-LETT-3356. Also published in The Correspondence of Charles Darwin, vol. 10.

Van Wyhe, J. & Rookmaaker, K. (2015) Alfred Russel Wallace: Letters from the Malay Archipelago. Oxford University Press, Oxford.

Lived and learned: #BES2016 in review

I returned last night from the 2016 Annual Meeting of the British Ecological Society, held in Liverpool. Going to ‘the BES’ is fast becoming an annual tradition for me, as it is for hundreds of ecologists. As always, I had a great time, and learned a lot – not just fascinating snippets from the coalface of ecological science, but also a lot of more general lessons about how to get the most out of big conferences like this one, and a scientific career more generally. For my own sake as much as anybody’s, I thought I’d coalesce some of those thoughts here.

1. Engage with the public (don’t preach at them)

The conference was book-ended by talks that addressed the difficulty of turning your science into practice. Much of what ecologists do has a real-world application – whether we work in conservation, monitoring, or environmental change, I think we all want to see our research getting used, but it isn’t always as simple as ‘publish the paper, wait for people to read it’. Opening the conference, Mike Begon tackled Michael Gove’s comments that “people have had enough of experts”. Mike pointed out that people are more likely to respond to emotionally attractive messages than plain facts, no matter how persuasive those facts may be – but importantly, there is no reason why we can’t use facts as the moral justification to underpin those messages.

Later, in the final plenary, Hugh Possingham distilled his own experiences of trying to get his research into policy in his native Australia into the three simple messages in the tweet above. Hugh also highlighted the importance of ‘environmental heroes’, who can campaign on an issue over much longer timescales than is really possible for an academic. Somebody who definitely qualifies as an environmental hero retired this week after 13 years as CEO of Butterfly Conservation – best wishes for the future to the wonderful Martin Warren.

2. Step outside your comfort zone

This year’s conference marked the first time I had presented a chapter of my PhD (and hopefully soon a paper) that tackled DNA-based approaches for detecting ‘stuff in the environment’ and tested whether they could be applied to my area of interest, pollination interactions. I’m getting fairly experienced now at presenting talks at conferences – I’ve done both small conferences (where, conversely, the audience tends to be larger) and big conferences (where the audience can be much more topic-focussed and expert). But this was a methodological talk, about skills I had almost entirely learned within the last 12 months. What if I got found out?

I needn’t have worried. My talk went well and people seemed to be interested (and some of them said very nice things on Twitter!). A couple of people came up to chat afterwards who, it turned out, worked in related fields and had found elements of my talk useful – making those kinds of contacts was exactly why I’d wanted to give the talk in the first place!

On a related note, I spent Wednesday afternoon chairing a session on Global Change Ecology. Again, something I had never done before, but it worked out great, serving as simultaneously a gentle and a rigorous introduction to session-chairing. Gentle – because it was a small session in a big room, so it never felt too intimidating. Rigorous – because I faced all the challenges that chairing can throw up (speakers worried about their timing, stony silences when asking for audience questions, and at one point a hint of technical issues!). Next time I’m given the chance to chair a session, I’ll be much more confident.

3. Be nice

In a year of celebrity deaths, ecologists mourned the loss of Ilkka Hanski. I recently submitted a paper, based on my dissertation project, that investigated the spatial ecology of a moth species, and so I have a little familiarity with Ilkka’s work on metapopulations. Therefore, I decided to attend as much as I could of the session on Tuesday afternoon celebrating his life’s work. That such a session took place at all was remarkable – how many past attendees of the BES must pass on every year? – but I was struck by both the high turnout and the extraordinary fondness with which each speaker talked about Ilkka. Something to aspire to.

The following morning, Alison Hester – charged with the impossible task of giving the 12 Months in Ecology lecture after the year that’s been! – did a marvellous job of reminding us that it’s not all doom and gloom. There have been some fascinating discoveries this year, and great progress on the issue of microplastics. With Brexit looming and the election of President Trump, it’s easy to feel down – but it’s not certain how things will pan out, and maybe we ecologists, as a collective, can make a difference.

4. You’re not an imposter!

Imposter syndrome – almost all academic scientists will be familiar with it (as a side-note, congratulations to the BES for being proactive in organising a workshop about stress, and especially for targetting it at PIs, to help them look after their students. A great shame it had to be cancelled at the last minute, and I hope it will be back on the programme next year). After last year’s conference, I was honoured to have been named a runner-up for the Anne Keymer Prize for Best Student Talk. On Tuesday evening, I was invited to a drinks reception attended by Society prize-winners, current and past Presidents, and this year’s plenary speakers. Wow – I was terrified! Fortunately, the lovely Zoe Davies (who really did a marvellous job of putting this year’s programme together) spotted me looking nervous and swept me up, immediately introducing me to “Bill” (that’s Bill Sutherland to us mere mortals!). Within the hour I was chatting away to “Pedro” and “Jordi” – authors of this year’s Marsh Book Award winnerMutualistic Networks – about my own research on nocturnal pollination networks. Of course, I still felt like an imposter – but if anybody in the room felt in any way superior to me, they hid it well. Some of the best ecologists around – but totally grounded and humble.

5. The more you see, the more you know

This was my third BES; since starting my PhD I’ve also done two Royal Entomological Society conferences, two Butterfly Conservation/De Vlinderstichting conferences, and a host of other smaller meetings. At the first of these, I knew practically nobody and spent large chunks of the meeting standing awkwardly by my poster. This time out, it took me until Wednesday lunchtime to finally catch up with everybody I’d hoped to see at the BES, despite ‘networking’ during every single break. Along the way, I met a bunch of new people, ranging from MSc students to high-profile PIs, many of them through introductions by my existing contacts. I’m astonished by how many friends I’ve made in three short years in academia – long may it continue.