In the 1960s, W. D. Hamilton introduced the world to kin selection. But whilst his paper was in review, he was far away in Brazil... watching the primitively eusocial wasp Polistes canadensis*. Surprisingly, worker wasps were moving between nests, seemingly lending a hand to the neighbours. This was odd. If wasps were supposed to be maximising their inclusive fitness, why did they seem to be squandering helping effort on more-distant relatives living next-door?
Hamilton added this strange fact to a section called 'Anomalies' in the second of his 1964 papers, and speculated that it might be explained by kin selection theory if (a) wasps are less useful at home and (b) neighbour nests are still related to some degree. Since then, two more hypotheses have been proposed. In our new paper based on fieldwork in Panama (thanks to National Geographic and the Smithsonian Tropical Research Institute for funding!), we show that these newer hypotheses don't work. We find that Polistes canadensis nests appear to experience diminishing returns to cooperation that confirm Hamilton's hunch: wasps can become less useful at home, so altruistic wasps can improve their inclusive fitness by switching nests.
This fieldwork involved working in some surprising parts of Panama, including a derelict loo. I've somehow managed to have an ode to derelict Panamanian loos posted on the Nature Ecology and Evolution blog, here:
The paper is here:
*a classic mistake in zoological naming, as P. canadensis lives nowhere near Canada.
We have a new perspectives article out, proposing that interactions with rival outsiders could help explain the large amount of unexplained variation in brain size between species.
Here's the paper: https://www.nature.com/articles/s41467-020-18780-3
I've written a blog post on the Nature Ecology and Evolution community website here: natureecoevocommunity.nature.com/posts/napoleonic-intelligence-and-the-evolution-of-big-brains
In a recent Biology Letters paper, we ask whether the embattled haplodiploidy hypothesis (the idea that hymenopteran females are more disposed to evolve sterile helpers than diploids are) is affected by sex-specific condition-dependence. In principle, a female bee's reproductive success may depend more strongly on her physical condition than does a male bee's reproductive success: she must face the energetically-demanding challenge of nest founding (and often overwintering), whilst males face only the challenge of succeeding in mating. (This is the opposite way around to the condition-dependent asymmetry familiar in vertebrates, where male reproductive success depends more strongly on condition).
If female quality determines future nest-founding success, altruism that increases sibling quality will be easier to evolve in haplodiploids than in diploids. More generally, we suggest that empirically quantifying the payoffs of altruism in insects has focused largely on sibling quantity (how many brothers and sisters can I raise?), but that effects on sibling quality remain incompletely understood.
Wasps have a serious PR problem. Here's one proposal to win hearts and minds (ignoring the occasional kid with anaphylactic shock):
I'm really grateful for the funding and fantastic support of the National Geographic Society (NGS) for my wasp fieldwork in Panama. This week, Nat Geo posted some coverage of the project online - link here: http://www.nationalgeographic.co.uk/animals/2018/03/meet-slow-mo-ninja-discovering-why-wasps-work-others.
For some footage of our beautiful wasps - from our Panama populations, many taken by Pieter Botha - see: https://video.nationalgeographic.com/video/news/180307-wasps-origin-animal-altruism-tiny-backpacks-vin-spd
This week we published a paper in Nature on the evolution of altruism in changeable, unpredictable habitats. Recently, biologists have pointed to a number of striking connections between animal cooperation and environmental stochasticity - particularly in cooperatively-breeding birds. We decided to go back to basics and see what happens to Hamilton's rule in these stochastic environments. I've written a blog post on the background to the study over at the Nature Ecology & Evolution Community site.
When is an termite mound like a leopard? Are they both - in some sense - 'organisms'? If that question makes you (a) annoyed or (b) intrigued, this is the event for you. Dr Heikki Helanterä and I are chairing a symposium on whether social insect biologists should embrace or reject the embattled concept of the 'superorganism'. It'll be at the social insect biology congress (iussi2018.com) in Guarujá, Sao Paulo State, this August. If you're a social insect biologist with strong thoughts either way, get your abstracts submitted! Talk slots are 15 mins.
Abstracts submission is at http://iussi2018.com/node/1014.
Recently-published coverage on the FAPESP website of our fieldwork radio-tagging wasps in Sao Paulo state: http://agencia.fapesp.br/vespa_compartilha_alimento_com_a_vizinhanca/27076/
My PhD has been a series of wasp-hunting forays through French Guiana, Panama, and Brazil - and people sometimes seem a bit surprised at all this South American wasping. "Surely," they say, "there are perfectly good wasps in the UK?" Whilst my wasping loyalties are definitely with the wasps of South America - from the night-dwelling Apoica in the rainforest to the spectacular armadillo wasps of the cerrado - it's true that British wasps aren't to be sniffed at. After all, we have hornets, and even devoted wasp-killing maniacs will concede that they are fairly impressive.
So, to correct the balance a little bit, here are some shots of British wasps (hornets, no less...) from a park in London, which we collected this week for a three-year project being undertaken Daisy (a postdoc in the Sumner lab, probing the very origins of sociality in the wasp world...):
Spectacular photo taken by Alice on our recent field trip to Brazil! Technically, it's a boring beetle, which seems a bit harsh.
May I present the giant metallic ceiba borer, Euchroma gigantea, modelled by Sam:
Sitting at Madrid airport on journey back from Sao Paulo, Brazil, where it's been a busy month studying a different paper wasp: the ominously-named Polistes satan.
Why are they called P. satan? I suspect that it's because the first thing you notice in P. satan is that many individuals have a black face with red eyes. Does look fairly satanic. Others have red faces with black splotches. This variation in facial colouration is thought to serve a signalling function, at least in foundresses (paper here). Here, for instance, is a typical black-faced female:
The second thing you notice about them is that they prefer stinging whoever isn't wearing the bee suit.
The third thing you notice is that they are all wearing tiny radio-transmitter backpacks.
Working with Professor Fabio Nascimento's lab at the University of Sao Paulo in Ribeirao Preto, we have once again been using miniature radio-transmitters to study Polistes behaviour. This is all part of the project I have been doing in French Guiana and Panama, and follows on from the 2007 work by my supervisor Seirian Sumner (and later fascinating experiments by Thibault Lengronne).
The four of us - Andre de Souza (post-doc at USP), Sam Morris, Alice Chadwick, and me - have spent the month in two field sites (an abandoned farmhouse and a small fazenda, both in a valley near the small town of Pedregulho in the north of Sao Paulo State). The landscape was very different to Panama: not tropical lowland rainforest for P. satan, but rather the transition zone between cerrado and Atlantic forest ecosystems, which seems to be popular with the toucans and looks something like the Yorkshire Dales with more palm trees:
Next step is to analyse the pile of data from this blitz month of data-collecting. We have movement networks from the radio-tags, aggression data from behavioural experiments, hydrocarbon samples from the cuticles, microsats for genotyping, and facial colouration for matching with behavioural histories. Lots to be getting on with!
Massive thank you to Fabio (for so generously hosting us at USP and supervising the project), Andre (who had to tolerate dragging a bunch of confused gringos around small Brazilian towns), Sam (who gallantly left his giant dinosaur ants behind to spend a sweaty month dodging wasps and piglets), and Alice (who recklessly followed her crazy boyfriend to Brazil to run around grabbing wasps). Obrigado todos!
Just written a blog post over at National Geographic's 'Explorers Journal', on recent field trip to Panama - explaining exactly why I've now been stung over 70 times for this wasping PhD... Link's here:
I'm writing this from a field station on the coast of Panama. Darkness is falling over a coral lagoon and the fireflies are beginning to drift through the grass. This has been my second field trip of the PhD, with the support of the National Geographic Society and the Smithsonian Tropical Research Institute (STRI), and after three months it's now drawing to an end. Pieter and I have encountered so many amazing things that it's hard to know where to start! Being here, it has been impossible to stop ogling at all the wonders everywhere you look - from capuchin monkeys flinging themselves through the branches to the iridescent flashes of morpho butterflies skitting through the forest. We've even stumbled upon the overgrown relics of Second World War bunkers smothered under strangler figs in the rainforest. Panama is a riot of diversity.
Every time I come back to the tropics, I fall in love with it all over again. As a bit of a wild Darwinian, it's a bit like squatting briefly in the temple of natural selection: here in tropics, there are 'endless forms most beautiful' in the most stupendous, magnificent, awesome sense possible. Can't wait to get back here!
I've been busy getting to know 17,000 baby wasps over the past two months in Panama, which explains my slight silence on the blog front. My species is the striking dark red Polistes canadensis, but we've also run into a number of other species (from the tiny Polybia to the redoubtable and oddly-beautiful Synoeca - one of the few insects to possess the maximum score on the Schmidt Sting Pain Index). Above, in a tree in the Bay of Colon is Apoica pallens, a strange white wasp because it spends the daytime huddled neatly over the brood and does all its foraging during the night.
Of course, no blog post should be without a snap of P. canadensis, so here is my PhD species in all its glory - making full use of the daytime:
These colonies are on the Caribbean side of Panama, near the mouth of the Chagres River. Here's Pieter looking out at the river as the evening draws in:
Ever wondered what a God's-eye-view of civil war looks like? No, neither have I, but I have wondered about something similar - a God's-eye-view of civil war within wasp colonies. In French Guiana last year, I did exhaustive behavioural analyses of the 'queen struggle' (the struggle for power over the colony that takes place amongst the surviving workers once the queen dies), all part of an experiment to test some intriguing hypotheses we have about wasp dominance behaviour.
Undergrad students Sinead Godson and Neil McIvor back in Bristol have been watching reams of video footage of this power struggle played out on two of my nests, and have produced fascinating projects using Elo rankings (the ranking system used in chess) to tackle questions of their own about these colonies. I'm currently working through each of my colonies to test my hypotheses. Using raw data from Sinead's work, I've plotted the dominance interactions between the wasps of one of the colonies from Sinnamary below. The colours refer to particular external information about the wasps - a categorisation system that will allow me to tease apart the behaviours.
So, if you want to know what a God's-eye-view of civil war (in wasps) looks like, it looks a little bit like this:
Watch this space as we go deeper into the social struggles of life on a primitively-eusocial wasp colony!
I'll be off to Panama in May for 4 months, and am on the look-out for a field assistant interested in ecology/evolution. We will be radio-tagging thousands of wasps in field sites likely to be in Colon Province (and potentially Lago Bayano to the east). It'll be hard (but fun) work. Apply if the prospect of long days of enthusiastic wasping in high humidity sounds like it could be your sort of thing....!
Deadline: 7th Feb. 2016
Field dates: 15th May to 10th September 2016
Here's the full advert:
In 2016, my fieldwork will be in Panama, where we know that 'drifting' (the mysterious movement of wasps between colonies, which is the focus of my PhD) takes place at extreme levels. Data from 2005 show that over half of detected wasps were 'drifters', so this is a real chance to get to the bottom of this Darwinian enigma.
It's all looking great. The only potential snag is that next year is likely to be an intensely dry year in Panama, due to the return of El Nino - a large-scale climatic phenomenon in the Pacific in which the colder eastern side of the Pacific warms up, leading to shifts in precipitation and temperature. Here's a handy guide from the Met Office:
So should I be worried? Here's my current thinking.
What's already happening in Panama?
The Panamanian rainy season in 2015 has been both slow to develop and weak. In fact, the current El Nino is looking suspiciously like it will be the strongest since 1997, which itself was the strongest on record . As STRI (the Smithsonian Institution's famous tropical research arm in Panama) have declared, "the total rainfall recorded up to August 18th was... the lowest ever recorded since records began in 1925" .
Should we be concerned?
It seems likely that next year's wet season will be unusually dry. This is a potential problem for a wasp biologist (me!), because wasp populations are likely to respond negatively to drought stress, both in terms of abundance and activity patterns.
It is too early to be sure what the effects will be. I am currently in contact with groups on the ground in Panama, and monitoring the state of the wasp populations over the coming months will be crucial.
Please contact me if you have any information!
If you're reading this from Central and South America and know the state of your local wasps, then I'd love to hear from you. Do let me know if your wasps are as abundant as normal, or whether there have been any noticeable adverse effects. Many thanks!
The great French botanist Francis Hallé (famous for his expeditions to the canopy on an inflatable raft) presents this fascinating and beautiful film. A definite recommendation! Here's the trailer...
In one of the more poetic moments of the Chronicles of Narnia, a guinea pig slips through the fabric of our world and finds itself in a transcendental woodland dotted endlessly with ponds. All is still. It later turns out that each pond is home to a separate universe. Our fluffy hero is a sort of unwitting higher-dimensional cosmonaut.
The vision of "the wood between the worlds" has stuck with me ever since I first read it as a child. But I now think that, in a genuine sense, we live in the wood. Surrounding us on all sides in our fractal world are swirling depths of life evolving, each complicated enough to be a world in itself. Millions of tiny fungi are hurling microcosmic lassos around passing nematode worms, driven by proteinaceous conversations between unseen genes; trillions of bacteria float in ethereal silence through private watery voids; miniature spiders are adventuring through the atmosphere suspended beneath diaphanous balloons of silk; ascomycetes in plumes of Saharan dust are wafting through Atlantic skies; and Demodex mites are crawling over the creases and follicles beneath your eyelashes like crampon-wielding explorers struggling over crevasses. Meanwhile, photons are careering into your retinas, splashing through oceans of rhodopsin eight minutes after erupting from nuclear explosions on the surface of the sun; behind your eyes, explosions of sodium ions are ushering action potentials down a filigree lacework of nerves; leaf-mining insects are scrawling their wavy signatures through two-dimensional flatlands; strepsipteran females, shrunken by relentless selection to lumps of ovary-bearing fat, jut from the stergites of paper-wasps; and we ourselves are navigating the world as nearly-chimaeric beings part-composed of bacterial cells vastly outnumbering our own. Our own universe is the "wood between the worlds" - and we can peer into each world-pond and find "caverns measureless to man".
We really should refuse to be sedated by the "anaesthetic of familiarity". However mad it sounds, life is dancing around us in a richness that defies belief. It makes you want to laugh.
In that supposed last word on the horrors of the humid tropics, Heart of Darkness, the forest wilderness of the Belgian Congo is not just a dank wasteland, oozing with unscrupulous ivory-traders and hungry cannibals. It is a remnant of Eden as it really was, a claustrophobic, uncivil emptiness - a phantom landscape inhabited by nauseous emblems of our own depravity, igniting mysterious lusts in western souls.
For Conrad, our most primaeval urges stir in the most primaeval landscapes. By implication, civilisation (as the antithesis to the forest) does not so much cultivate novel virtues as straitjacket our underlying tendency to barbarism. Tropical forests lie beyond a moral frontier, and thus deserve our contempt.
Heart of Darkness is a racist book (just see Chinua Achebe's 1975 polemic if you're unconvinced). Where does that racism come from? It comes, largely, from an obsession with contrasting the apparent turpitude - and dark inscrutability - of the Congo with the West, even if the thrust of the comparison is to underscore the delicate truth that the foundations of civilised society are not so far from the state of nature as we might wish to think. As Achebe put it, Conrad imagines his purgatorial rainforest resurrecting 'grotesque echoes of... forgotten darkness,... the avenging recrudescence of the mindless frenzy of the first beginnings' (p.1785).
Today, tropical forests tend to attract embarrassing gung-ho hyberbole about 'killer snakes' and 'giant spiders', and no end of TV blokes in camouflage being airlifted into the middle of nowhere smeared in mud to declare how dangerous everything is. Again, these forests offer the ultimate antidote to the familiar - they are alien, amoral, exotic worlds.
I think that there's a third way, which celebrates their extraordinary 'other-ness' without resorting to either Conrad-esque phantasmagoria or tabloid hysterics. It sees tropical rainforests as ambiguous, beautiful, enigmatic, infinite but knowable, and, ultimately, vulnerable. I genuinely feel that when we start seeing rainforests as neither hellish nor heavenly, but rather as vibrant, dynamic totems to the evolutionary processes that also created us, we will stand a much better hope of halting their destruction and the ongoing decimation of their indigenous inhabitants, who are neither 'savage' nor 'untainted' but simply alternative and legitimate ways of living on Earth.
In French Guiana, my main experiment involves plucking the queen from unsuspecting wasp colonies to (literally) see what happens. It takes about a day before those left behind realise that some kind of royal alien abduction has taken place. You can almost smell the tension. Nobody stops to pay their respects. The colony is plunged into a tiny power vacuum, a moment of private societal crisis in which only one wasp can wrestle control. That's the brutal charm of primitively-eusocial wasps - in principle, anyone could be egg-layer. It's a cut-throat meritocracy, in which the most thuggish pretenders to the throne end up in power.
Thibault and I recorded this scramble for control as it played out on a number of colonies over three hot weeks this summer. And I'm still recording it now, as most of the colonies were filmed in order to be analysed back in Bristol. I can then visualise this violent data in the form of networks (the network above, for instance, is a snapshot of eight hours of aggression over four days on a particular colony, in which each node is a wasp and each 'edge' an act of dominance). From this I'll be able to piece together the social status of the particular wasps I'm interested in using social network analysis, which will be the really intriguing bit. It's a bit like being God looking down to watch the back-stabbing Borgias take over Rome. Here goes into pandemonium!
And so Wasping Trip One comes to an end, with a swift sprint down a leafy runway on the outskirts of Cayenne. (I'll be back next year.) How did it go? Well, I returned with 2,000 wasps (deceased), a stick of cocoa, a few pinned cicadas, a large bill for car batteries, and a lot of radio-tag data which will - fingers crossed - reveal myriad wonders about how primitive animal societies evolve. Next step is processing hours of footage of my wasps vying for power after the abduction of their erstwhile queens...
Hi! I'm Patrick - an early-career postdoc in behavioural ecology. I completed my PhD in 2019, focused on Polistes paper wasps in South and Central America. I'm currently a Marie Skłodowska-Curie Fellow and Simons Society Junior Fellow in the Rubenstein Lab at Columbia University (New York) and the Radford Lab at the University of Bristol (UK), looking at the social behaviour and evolution of Africa's incredible wasps! I'm always keen to get involved in outreach to spread the word about these amazing animals.
Patrick Kennedy, University of Bristol
A blog about research, fieldwork, and trying not to get stung by big tropical wasps too often