In a previous life, before I became a successful, respected and well-balanced science writer, I did a PhD on the evolution of soldier castes in aphids. Happy days (not).
In this life — in 1996, to be exact — I travelled to an entomology conference in Florence. There, at a session on aphid biology, a fellow grad student and more talented researcher than myself called Sam Brown gave a presentation, coauthored with his supervisor Bill Hamilton, on the idea that the autumn colours of trees were a signal to marauding aphids of the strength of their antiherbivore defences.
Bright colours, their argument went, were an honest signal: only well-resourced trees able to make lots of the secondary compounds that plants use to make themselves unpalatable to herbivores would be able to make them. And aphids flying around in the autumn, looking for somewhere to lay their overwintering eggs, would shy away from such vivid displays.
The debate on the worth of this neat hypothesis has rumbled along for more than a decade now. Sceptics have pointed out that yellow pigments were there all along, but are only revealed when the leaf takes back it’s chlorophyll — leaves don’t turn yellow, they unturn green. Also that red pigments have other potential uses, centred on protecting the leaf as the plant takes it apart, chemically speaking. The latest update comes from Lars Chittka and Thomas Döring, two researchers on sensory ecology writing in PloS Biology.
To put it crudely, C and D’s piece plugs a forthcoming paper (this link wasn’t working when I checked) by them looking at colour vision in aphids. They find that Brown and Hamilton might have been deceived by their human’s-eye view. Aphids (and all other herbivorous insects looked at so far) don’t have good vision in the red — so red leaves wouldn’t look anything special to them. And yellow is powerfully attractive — it tickles their green receptors even more so than green itself, and brings insects flocking: ‘If trees wanted to deter herbivorous insects using color, yellow leaf coloration is about the worst strategy they could pick,’ they write.
The piece does such a good job of pouring cold water on the notion that autumn colours are signals that their final (inevitable) conclusion — the good old cry of ‘more research is needed’ rings a little hollow. Speaking as a rampaging adaptationist, who thinks that Hamilton has a good claim to having been the most important evolutionarybiologist since Darwin, I think that’s a bit of a shame, but there you go, beautiful theories, ugly facts and all that.
The essay also has some nice bits of history, and a lovely first sentence: ‘Most living things don't turn beautiful when they senesce’. But some editor should have stopped the use of ‘fascinating’ twice in the first paragraph. I can work out whether something is fascinating or not. (And while we’re about it, can we have a ten-year moratorium on the use of ‘intriguing’ in science journalism? It’s just ‘interesting’ wearing a false moustache.)
Thursday, August 16, 2007
Monday, July 16, 2007
Spontaneous order, fungal networks, and circuses
You wait ages to feel moved to post, and then three things come along at once. In no particular order…
Biological modularity can emerge as a spontaneous, self-organized process, say Ricard Solé and Sergi Valverde in J. R. Soc. Interface. By modularity they mean particular sets of interactions in the great web of biochemistry (rather than, say, organs):
Such a trend seems to call for an adaptive explanation. In particular, what seems to demand explanation are ‘motifs’ in these networks
Solé and Valverde cite a couple of adaptive explanations “based on a genetic programming approach”. But they don’t agree with them.
Instead, they say such modularity is the inevitable consequence of evolution by gene (or genome) duplication (“the driving force behind the evolution of complex organisms”, they say) followed by divergence, as evolution tinkers with the newly enlarged network of interactions (letting natural selection back in, it looks like)
I’ve clearly, as is my wont, become aware of this debate somewhere in the middle — the paper cites several is-modularity-evolution-or-is-it-self-organization? papers from the past few years. But, as far as I can tell, Solé and Valverde are saying that this is the first explanation for such modularity based on “fundamental, dynamical rules”.
In other network news, Proc R Soc B has just published a paper by Daniel Bebber et al. looking at fungal networks.
The challenges such a fungal mycelium faces are to explore its environment, exploit resources, transport them around the rest of the organism, and to be sufficiently robust to resist physical damage and the many fungus-eaters in the soil.
To investigate how fungi meet such challenges, they grew Phanerochaete velutina in the lab, growing it out from an inoculated lump of wood towards other lumps of wood. They found that the fungus began in exploratory mode, sending out lots of narrow filaments. But as it completed searching its environment it consolidated its resources into fewer, bigger bundles of hyphae, growing between maor resource patches, with more exploratory filaments in new territory, and crosslinks to provide some redundancy in the case of network damage. “Netowrk development”, say Bebber et al.
In other words, they’re stressing the diversity of different structures produced by flexibility and responsiveness to environmental variation, as much as whatever general laws such networks might have.
Philip Loring (who I believe blogs here) approaches questions of resilience, connectedness and persistence from a different angle in Ecology and Society. He proposes the circus as an icon of resilience, in that it has retained its identity while changing its contents — i.e. getting rid of freak shows and (mostly) animal acts.
The article, to my mind, contains a bit too much on the history of the circus, without exploring the implications of the circus-as-sustainability metaphor. Also, while ‘circus’ has survived for 200 years, most individual circuses haven’t. This is fine for institutions and systems, but not so much for species and ecosystems. But it’s a nice comparison.
Biological modularity can emerge as a spontaneous, self-organized process, say Ricard Solé and Sergi Valverde in J. R. Soc. Interface. By modularity they mean particular sets of interactions in the great web of biochemistry (rather than, say, organs):
Modularity is particularly obvious in cellular networks, where it can be detected at the topological level. These networks include the webs of interactions among proteins, genes, enzymes and metabolites or signalling molecules.
Such a trend seems to call for an adaptive explanation. In particular, what seems to demand explanation are ‘motifs’ in these networks
patterns of interconnections occurring in complex networks at numbers that are significantly higher than those in randomized networks.
Solé and Valverde cite a couple of adaptive explanations “based on a genetic programming approach”. But they don’t agree with them.
Instead, they say such modularity is the inevitable consequence of evolution by gene (or genome) duplication (“the driving force behind the evolution of complex organisms”, they say) followed by divergence, as evolution tinkers with the newly enlarged network of interactions (letting natural selection back in, it looks like)
I’ve clearly, as is my wont, become aware of this debate somewhere in the middle — the paper cites several is-modularity-evolution-or-is-it-self-organization? papers from the past few years. But, as far as I can tell, Solé and Valverde are saying that this is the first explanation for such modularity based on “fundamental, dynamical rules”.
In other network news, Proc R Soc B has just published a paper by Daniel Bebber et al. looking at fungal networks.
they have evolved to explore and exploit a patchy environment rather than ramify through a three-dimensional organism. Unlike all the other biological transport systems studied, the fungal network is not part of the organism, it is the organism.
The challenges such a fungal mycelium faces are to explore its environment, exploit resources, transport them around the rest of the organism, and to be sufficiently robust to resist physical damage and the many fungus-eaters in the soil.
To investigate how fungi meet such challenges, they grew Phanerochaete velutina in the lab, growing it out from an inoculated lump of wood towards other lumps of wood. They found that the fungus began in exploratory mode, sending out lots of narrow filaments. But as it completed searching its environment it consolidated its resources into fewer, bigger bundles of hyphae, growing between maor resource patches, with more exploratory filaments in new territory, and crosslinks to provide some redundancy in the case of network damage. “Netowrk development”, say Bebber et al.
involves over-production of links and nodes in the exploratory phase, followed by selection and positive reinforcement of some links and recycling of the remainder during the consolidation phase … A
similar sequence of events is apparent in the development of other biological transport networks including those formed by acellular slime moulds [and] foraging ant trails … and may well represent a universal feature of self-organized biological networks. However, in each of these systems, the final network structure is likely to represent a context-specific balance between the need for efficient transpor t, cost and robustness.
In other words, they’re stressing the diversity of different structures produced by flexibility and responsiveness to environmental variation, as much as whatever general laws such networks might have.
Philip Loring (who I believe blogs here) approaches questions of resilience, connectedness and persistence from a different angle in Ecology and Society. He proposes the circus as an icon of resilience, in that it has retained its identity while changing its contents — i.e. getting rid of freak shows and (mostly) animal acts.
Through the many forms they have taken over the last 150 yr, circuses have changed significantly while sustaining a singular identity. As a successful and enduring social system, their intriguing history exposes the nuances of sustainability theory, from resilience to pathologies, and illustrates that sustainability requires a complex dynamic between identity, tradition, and change.
The article, to my mind, contains a bit too much on the history of the circus, without exploring the implications of the circus-as-sustainability metaphor. Also, while ‘circus’ has survived for 200 years, most individual circuses haven’t. This is fine for institutions and systems, but not so much for species and ecosystems. But it’s a nice comparison.
Thursday, May 17, 2007
Survival of the likeliest?
There's a feature by me in the current PLoS Biology (and it's free!) on whether natural selection can be explained by the laws of physics, specifically thermodynamics and statistical mechanics. This looks at work of Roderick Dewar on Maximum Entropy Production (MEP), Adrian Bejan's constructal theory, work by Eric Smith at Santa Fe on self-organization and metabolism, and a few other things. The basic idea is that, by looking at the flows of energy and matter, we can predict and quantify the path and results of evolution.
This is something I've been thinking about for a couple of years — I put a bit about it in the first draft of ITBOAH, but took it out, 'cos it wasn't really working. And I wrote a piece for Nature looking at MEP from a more climate- and ecological viewpoint, which didn't go so much into the evolutionary implications. So I'm very glad that this is finally seeing the light of day.
This is something I've been thinking about for a couple of years — I put a bit about it in the first draft of ITBOAH, but took it out, 'cos it wasn't really working. And I wrote a piece for Nature looking at MEP from a more climate- and ecological viewpoint, which didn't go so much into the evolutionary implications. So I'm very glad that this is finally seeing the light of day.
What I did on my holiday
I've just got back from three weeks on holiday in Andalucia. Two things I learnt:
Trenhotel good. If you don't dilly-dally, you can eat lunch in London one day, and in Seville the next, without leaving the ground. The overnight journey, from Paris to Madrid, is comfy and fun (cf flying) – there's a bar and restaurant on the train. The mighty seat61.com has all the details.
Plasticultura bad. When I saw vegetables in my local supermarket from Spain, I had, I suppose, a dim image of a happy campesino weidling a mattock and whistling a song. In fact, it seems that they are grown in one of a never-ending series of plastic greenhouses that, in eastern Andalucia (around Almeria) fills just about every bit of land between the sea and the mountains.
There's a danger in knee-jerk disapproval of the unsightly — I'm sure there are outdoor forms of farming that have just as much environmental impact, but, because they fit our idea of what farmland should look like, don't make you as depressed as a sea of plastic. And there are arguments that, where we farm, we should do it as intensively as possible, so that is uses the minimum of land and leaves more for nature (whatever one means by that). (Although in a country like the UK, where farmland and countryside are the same thing, this would be tricky.) Plasticultura, or invernaderos, however, do seem to take out more water, and put back more nitrates, than the land can support. Plus they are hellish places to work (although not so hellish that no one wants to work there).
To find out more, try this article from the Ecologist for more on water, the environment and farming in southern Spain, this from John Vidal on the Spanish drought, this lecture by Felicity Lawrence for intensive farming in general, and here (recommended) for photos of plasticultura farming.
I shan't be buying Spainsh veg any more, thus making my winter diet even more cabbage-based than previously.
Trenhotel good. If you don't dilly-dally, you can eat lunch in London one day, and in Seville the next, without leaving the ground. The overnight journey, from Paris to Madrid, is comfy and fun (cf flying) – there's a bar and restaurant on the train. The mighty seat61.com has all the details.
Plasticultura bad. When I saw vegetables in my local supermarket from Spain, I had, I suppose, a dim image of a happy campesino weidling a mattock and whistling a song. In fact, it seems that they are grown in one of a never-ending series of plastic greenhouses that, in eastern Andalucia (around Almeria) fills just about every bit of land between the sea and the mountains.
There's a danger in knee-jerk disapproval of the unsightly — I'm sure there are outdoor forms of farming that have just as much environmental impact, but, because they fit our idea of what farmland should look like, don't make you as depressed as a sea of plastic. And there are arguments that, where we farm, we should do it as intensively as possible, so that is uses the minimum of land and leaves more for nature (whatever one means by that). (Although in a country like the UK, where farmland and countryside are the same thing, this would be tricky.) Plasticultura, or invernaderos, however, do seem to take out more water, and put back more nitrates, than the land can support. Plus they are hellish places to work (although not so hellish that no one wants to work there).
To find out more, try this article from the Ecologist for more on water, the environment and farming in southern Spain, this from John Vidal on the Spanish drought, this lecture by Felicity Lawrence for intensive farming in general, and here (recommended) for photos of plasticultura farming.
I shan't be buying Spainsh veg any more, thus making my winter diet even more cabbage-based than previously.
Oekologie #5
Jeremy Bruno over at the Voltage Gate has done an erudite job on this month's Oekologie blog carnival (my own hosting effort is here).
Wednesday, April 11, 2007
Guardian podcast
I'm on this week's Guardian science podcast, talking about D'Arcy Thompson, polymathy (is that a word?) and ITBOAH with Alok Jha and the other young rowdies.
Father and son
Among the many, many stories I've recently written for news@nature.com recently is one about changing dates of the UK mushroom season. There's been a huge effect in response to warming — the autumn season is twice as long, and some mushrooms are popping up in spring, as well as autumn.
This is a lovely example of you-never-know-when-it'll-come-in-handy data collection. The data — ranging from 1950-2005 — were collected by Edward Gange, stonemason by day and fungal recorder for the Wiltshire Natural History Society in his spare time. The lead author on the paper is his son, ecologist Alan Gange. Isn't that nice?
Another good thing about this piece is that it gave me a gave me a chance to interview Andy Overall, one of whose fungus forays I attended last year.
Back in the dim'n'distant, I had a lot of fun writing a longer piece for Nature about ecologists using data collected by amateurs to measure the effects of climate change on living things. If you ask me, this is probably the most important ever non-specialist contribution to science. Always glad to hear of any other candidates, though.
This is a lovely example of you-never-know-when-it'll-come-in-handy data collection. The data — ranging from 1950-2005 — were collected by Edward Gange, stonemason by day and fungal recorder for the Wiltshire Natural History Society in his spare time. The lead author on the paper is his son, ecologist Alan Gange. Isn't that nice?
Another good thing about this piece is that it gave me a gave me a chance to interview Andy Overall, one of whose fungus forays I attended last year.
Back in the dim'n'distant, I had a lot of fun writing a longer piece for Nature about ecologists using data collected by amateurs to measure the effects of climate change on living things. If you ask me, this is probably the most important ever non-specialist contribution to science. Always glad to hear of any other candidates, though.
Tuesday, April 03, 2007
The coming era of jellyfish ascendancy
I admit it, my devotion to the work of George Monbiot (or The Monb, as he's apparently known in some environmental circles) borders on the unhealthy.
But this piece on marine conservation, and the overfishing of top predators such as sharks, is really excellent.
The Spanish fishing industry, he writes, is "traditionally dominated by Galician fascists". There's no fascist like a Galician fascist.
But this piece on marine conservation, and the overfishing of top predators such as sharks, is really excellent.
The Spanish fishing industry, he writes, is "traditionally dominated by Galician fascists". There's no fascist like a Galician fascist.
Thursday, March 29, 2007
Some stories what I wrote, and one that I didn't
I'm working for news@nature for a few weeks, so I haven't had a chance to write much stuff for El Gentraso.
What I have written is a story about what the direction a dog's tail wag means, one about 'semi-identical' twins', both of which were subsequently picked up (i.e. copied) elsewhere.
I found them, not by any particular piece of investigative brilliance, but by looking at journal tables of contents. As a science journalist, if you look beyond the press releases on sites like Eurekalert and Alphagalileo, you'll often find that you've got no company.
The twins story, in particular excited a rush of comments to Nature's newsblog, mainly from people who thought they were, or had had, semi-identical twins. But probably aren't/haven't.
Not that incentives for good practice should be necessary, but writing for online is a useful reminder of what people might make of your stories - it's always sobering to see the expressions of hope that come in after any story on a potential cure for a disease or disability, however caveat-laden the story.
More recently, I've written about cane toad distribution and mammal evolution.
So doing all that has prevented me from blogging about John Lanchester's masterly essay on climate change in the LRB. This has one of the best intros I've seen in a long time:
It makes you think (and tempts you to act). My guess is that most people don't like doing violence, to property or people, and that we shy away from escalating a confrontation, usually for good reason. Maybe that's another word for cowardice, or apathy, though.
I don't bandy the words 'essential reading' about much, but I'd say that this is. The one thing I might take issue with is Lanchester's approving words on James Lovelock's advocacy of nuclear power.
I don't have an issue with nuclear power per se, and I think it should probably be in our energy portfolio. But George Monbiot's 'Heat' argues that, in practical terms, building a new generation of power stations would take so long that it's not a quick fix - we might as well go all out for renewables and carbon sequestration - and that energy efficiency gives the best return in carbon-saved-per-pound-spent.
One's always tempted to find rational arguments to support things you emotionally favour, but Monbiot makes an effort to do his sums - and also shows that no one really knows what's what when it comes to how we're going to get our energy.
What I have written is a story about what the direction a dog's tail wag means, one about 'semi-identical' twins', both of which were subsequently picked up (i.e. copied) elsewhere.
I found them, not by any particular piece of investigative brilliance, but by looking at journal tables of contents. As a science journalist, if you look beyond the press releases on sites like Eurekalert and Alphagalileo, you'll often find that you've got no company.
The twins story, in particular excited a rush of comments to Nature's newsblog, mainly from people who thought they were, or had had, semi-identical twins. But probably aren't/haven't.
Not that incentives for good practice should be necessary, but writing for online is a useful reminder of what people might make of your stories - it's always sobering to see the expressions of hope that come in after any story on a potential cure for a disease or disability, however caveat-laden the story.
More recently, I've written about cane toad distribution and mammal evolution.
So doing all that has prevented me from blogging about John Lanchester's masterly essay on climate change in the LRB. This has one of the best intros I've seen in a long time:
It is strange and striking that climate change activists have not committed any acts of terrorism. After all, terrorism is for the individual by far the modern world’s most effective form of political action, and climate change is an issue about which people feel just as strongly as about, say, animal rights. This is especially noticeable when you bear in mind the ease of things like blowing up petrol stations, or vandalising SUVs. In cities, SUVs are loathed by everyone except the people who drive them; and in a city the size of London, a few dozen people could in a short space of time make the ownership of these cars effectively impossible, just by running keys down the side of them, at a cost to the owner of several thousand pounds a time. Say fifty people vandalising four cars each every night for a month: six thousand trashed SUVs in a month and the Chelsea tractors would soon be disappearing from our streets. So why don’t these things happen? Is it because the people who feel strongly about climate change are simply too nice, too educated, to do anything of the sort? (But terrorists are often highly educated.) Or is it that even the people who feel most strongly about climate change on some level can’t quite bring themselves to believe in it?
It makes you think (and tempts you to act). My guess is that most people don't like doing violence, to property or people, and that we shy away from escalating a confrontation, usually for good reason. Maybe that's another word for cowardice, or apathy, though.
I don't bandy the words 'essential reading' about much, but I'd say that this is. The one thing I might take issue with is Lanchester's approving words on James Lovelock's advocacy of nuclear power.
I don't have an issue with nuclear power per se, and I think it should probably be in our energy portfolio. But George Monbiot's 'Heat' argues that, in practical terms, building a new generation of power stations would take so long that it's not a quick fix - we might as well go all out for renewables and carbon sequestration - and that energy efficiency gives the best return in carbon-saved-per-pound-spent.
One's always tempted to find rational arguments to support things you emotionally favour, but Monbiot makes an effort to do his sums - and also shows that no one really knows what's what when it comes to how we're going to get our energy.
Wednesday, March 21, 2007
One of the best things about being a science writer...
Is sitting down on a Monday, and turning out a story about something that, that morning, you knew less than nothing about - the 248-dimensional exceptional Lie group E8. And then coming in on Tuesday and writing a story about a burrowing dinosaur. Who knew?
Thursday, March 15, 2007
Oekologie #3
Here beginneth the third edition of the Oekologie blog carnival. Thank you everyone who took the time to send in posts. It was great to receive such a diverse bunch — we've got just about every group of organism and every part of the world represented, at scales ranging from the global to the backyard, and addressing just about every issue you can think of. So here we go…
Crime! Julie from The Human Flower Project has sent in a cool story on the banning of the Hungarian hovirag harvest. The hovirag is a snowdrop, sold in Hungary as a mark of coming spring, but now grievously over-picked (and with a street value somewhat greater than crack, apparently). The flower is also the source of the protein that, put into to GM potatoes, led to the controversy around the experiments by (Hungarian-born) Arpad Puzstai.
Deceit! GrrlScientist at Living the Scientific Life posts on a neat piece of mimicry — the moth that pretends to be a jumping spider.
Pestilence! Jennifer Forman Orth at the Invasive Species Weblog reports on beech bark disease, which involves an invasive insect infesting the tree, which leads to a fungal infection, which leads to trouble.
Meanwhile, showing that not you don't need to cross an international borders to be an invasive species, Paul Decelles at The Force that Through… points the finger at red cedar, a native of the eastern US now making trouble further west. And then defends his position.
Goats! Aydin at Snail's Tales discusses the impact of goats on the past and future vegetation of the Mediterranean. "If we want to return at least some of the land to its original, pre-grazing, pre-human state, the goats must go," he says.
The Mediterranean is interesting because it has diverse plant life, even though it has seen millennia of heavy human impact, suggesting that the plants have coevolved with people and their animals. (This has also equipped Mediterranean plants to do well in places like California and Australia.) But, of course, whether this flora was in place before people showed up — and if not, what was — is another matter.
That's enough exclamation marks.
Fish: Stephen Leahy at, um, Stephen Leahy points us to his story discussing the concept of peak fish — global catches have levelled off (not sure what's happened to global fishing effort, but it seems unlikely to have fallen), and may soon start falling.
Another option for providing seafood is fish farming. The US government has proposed to extend fish farming into federal waters, 3 to 200 miles offshore. But Lish at Science Ripsaw is worried it that this would deplete nutrients and increase pollution.
Oil: Tom Elko at Sky Blue Waters reports on the concerns around the environmental impact and property rights issues of the MinnCan pipeline. If built (which is looking likely) it would carry crude oil from Canadian oil sands (which are environmental and carbon-emissions bad news in themselves) to refineries in Minnesota.
Milk(weed): Miconia at A Neotropical Savanna meditates on Asclepia.
I know it's not a very scientific reaction, but…
Eeuuw: GrrlScientist reports on a blind, cave-dwelling Madagascan snake (that looks like a worm), rediscovered more than 100 years after the last known specimens were collected. They avoid the light, and sniff out their prey — the eggs and larvae of ants and termites.
Eeuuw II: The pygmy-hog-sucking louse (as a part-time copyeditor and punctuation geek, I place those hyphens with some confidence). Sticking up for the bloodsuckers at Endangered Ugly Things, Garfman makes the excellent point that every large, cuddly and charismatic species in danger of extinction also has (probably several) parasites that depend on it for their own survival. Coendangered is the technical term, apparently.
Mangroves: On the Ecological Society of America's blog, Edward Barbier has posted an authoritative guide to the issues surrounding the loss and restoration of mangrove forests, particularly regarding their ability to buffer against storm and tsunami damage.
Barbier — who has done lots of research into the interactions between development, mangroves and ecosystem services (the mangroves usually come off worse) — argues that the debate around the benefits and costs of replanting, that have followed from the 2004 Indian Ocean tsunami, is oversimplified.
Cheetahs: Over at Laelaps, Brian Switek highlights something that was new to me — Iranian cheetahs. Brian writes about the Wildlife Conservation Society's work to conserve this population.
(This also made me intrigued about another thing I know nothing about — what issues a US conservation organizations faces when it works in Iran — in terms of dealing with both the Iranian and US governments.)
Bats: Jennifer Pinkley at The Infinite Sphere discusses how the eastern pipistrelle's more catholic taste in habitat and roosts has made it "more adaptable to changing environmental pressures" than its close relative the gray myotis.
Microbes: Coturnix at A Blog Around the Clock alerts us to PLoS Biology's glut of papers on ocean microbial diversity (i.e. metagenomics). This is way-cool stuff right now (see also previous post on this blog).
Semantics: Matt at the Behavioral Ecology blog has sent in a post entitled 'Is rape adaptive?', which also discusses whether 'rape' is a good word to apply to forced copulations in (non-human) animals. The consensus appears to be not and, although I usually favour strong words and try to avoid jargon, I agree.
Celebrity: Mike at 10,000 birds muses on the ethics of twitching, and the motivations of twitchers. Naturalists, paparazzi, rubberneckers, or all of the above?
Memories: for me at least, with Jeremy Bruno, and the Voltage Gate's guide to tropical dry forest.
Jeremy mentions Guanacaste in Costa Rica, conservation success story (thanks to the idea of introducing large domestic herbivores to do the seed-dispersal job once done my extinct species), macroecological hotspot, and a place I visited while researching ITBOAH (I had to get a mention in somewhere). One of the remarkable things about Costa Rica is that this forest is about half-an-hour's drive from cloud forest containing a totally different set of species.
Global: John Feeny at Growth is Madness! muses on whether spreading the news that we're in the middle of the earth's sixth mass extinction since the Cambrian will help turn people on to conservation.
And Vbecer00 at Reconciliation Ecology also touches on the issue of how you get people to care in his/her post on, well, just about every issue in conservation — why do it, how to do it, and how to make it work.
Local: Join Dave Bonta at Via Negativa for a walk in the snow in Plummer's Hollow, and benefit from his sharp eyes. The man knows his neighbourhood, and his shrews.
Or, you could visit Wayne at Niches, and read his reports on the effects of heavy rains on the creeks on his property in Athens, Georgia.
And finally….
Personals: Johan Stenberg is in Sweden, feeling lonely. Cheer Johan up and join his journal club on insect-plant ecology, at (where else but the) Insect-Plant Ecology blog.
So there you have it. Oekologie — opening your minds, grossing you out, winding you up, bringing you together. Thanks again, and be sure to check out the next edition in a month's time on the Behavioral Ecology Blog.
Crime! Julie from The Human Flower Project has sent in a cool story on the banning of the Hungarian hovirag harvest. The hovirag is a snowdrop, sold in Hungary as a mark of coming spring, but now grievously over-picked (and with a street value somewhat greater than crack, apparently). The flower is also the source of the protein that, put into to GM potatoes, led to the controversy around the experiments by (Hungarian-born) Arpad Puzstai.
Deceit! GrrlScientist at Living the Scientific Life posts on a neat piece of mimicry — the moth that pretends to be a jumping spider.
Pestilence! Jennifer Forman Orth at the Invasive Species Weblog reports on beech bark disease, which involves an invasive insect infesting the tree, which leads to a fungal infection, which leads to trouble.
Meanwhile, showing that not you don't need to cross an international borders to be an invasive species, Paul Decelles at The Force that Through… points the finger at red cedar, a native of the eastern US now making trouble further west. And then defends his position.
Goats! Aydin at Snail's Tales discusses the impact of goats on the past and future vegetation of the Mediterranean. "If we want to return at least some of the land to its original, pre-grazing, pre-human state, the goats must go," he says.
The Mediterranean is interesting because it has diverse plant life, even though it has seen millennia of heavy human impact, suggesting that the plants have coevolved with people and their animals. (This has also equipped Mediterranean plants to do well in places like California and Australia.) But, of course, whether this flora was in place before people showed up — and if not, what was — is another matter.
That's enough exclamation marks.
Fish: Stephen Leahy at, um, Stephen Leahy points us to his story discussing the concept of peak fish — global catches have levelled off (not sure what's happened to global fishing effort, but it seems unlikely to have fallen), and may soon start falling.
Another option for providing seafood is fish farming. The US government has proposed to extend fish farming into federal waters, 3 to 200 miles offshore. But Lish at Science Ripsaw is worried it that this would deplete nutrients and increase pollution.
Oil: Tom Elko at Sky Blue Waters reports on the concerns around the environmental impact and property rights issues of the MinnCan pipeline. If built (which is looking likely) it would carry crude oil from Canadian oil sands (which are environmental and carbon-emissions bad news in themselves) to refineries in Minnesota.
Milk(weed): Miconia at A Neotropical Savanna meditates on Asclepia.
I know it's not a very scientific reaction, but…
Eeuuw: GrrlScientist reports on a blind, cave-dwelling Madagascan snake (that looks like a worm), rediscovered more than 100 years after the last known specimens were collected. They avoid the light, and sniff out their prey — the eggs and larvae of ants and termites.
Eeuuw II: The pygmy-hog-sucking louse (as a part-time copyeditor and punctuation geek, I place those hyphens with some confidence). Sticking up for the bloodsuckers at Endangered Ugly Things, Garfman makes the excellent point that every large, cuddly and charismatic species in danger of extinction also has (probably several) parasites that depend on it for their own survival. Coendangered is the technical term, apparently.
Mangroves: On the Ecological Society of America's blog, Edward Barbier has posted an authoritative guide to the issues surrounding the loss and restoration of mangrove forests, particularly regarding their ability to buffer against storm and tsunami damage.
Barbier — who has done lots of research into the interactions between development, mangroves and ecosystem services (the mangroves usually come off worse) — argues that the debate around the benefits and costs of replanting, that have followed from the 2004 Indian Ocean tsunami, is oversimplified.
Cheetahs: Over at Laelaps, Brian Switek highlights something that was new to me — Iranian cheetahs. Brian writes about the Wildlife Conservation Society's work to conserve this population.
(This also made me intrigued about another thing I know nothing about — what issues a US conservation organizations faces when it works in Iran — in terms of dealing with both the Iranian and US governments.)
Bats: Jennifer Pinkley at The Infinite Sphere discusses how the eastern pipistrelle's more catholic taste in habitat and roosts has made it "more adaptable to changing environmental pressures" than its close relative the gray myotis.
Microbes: Coturnix at A Blog Around the Clock alerts us to PLoS Biology's glut of papers on ocean microbial diversity (i.e. metagenomics). This is way-cool stuff right now (see also previous post on this blog).
Semantics: Matt at the Behavioral Ecology blog has sent in a post entitled 'Is rape adaptive?', which also discusses whether 'rape' is a good word to apply to forced copulations in (non-human) animals. The consensus appears to be not and, although I usually favour strong words and try to avoid jargon, I agree.
Celebrity: Mike at 10,000 birds muses on the ethics of twitching, and the motivations of twitchers. Naturalists, paparazzi, rubberneckers, or all of the above?
Memories: for me at least, with Jeremy Bruno, and the Voltage Gate's guide to tropical dry forest.
Jeremy mentions Guanacaste in Costa Rica, conservation success story (thanks to the idea of introducing large domestic herbivores to do the seed-dispersal job once done my extinct species), macroecological hotspot, and a place I visited while researching ITBOAH (I had to get a mention in somewhere). One of the remarkable things about Costa Rica is that this forest is about half-an-hour's drive from cloud forest containing a totally different set of species.
Global: John Feeny at Growth is Madness! muses on whether spreading the news that we're in the middle of the earth's sixth mass extinction since the Cambrian will help turn people on to conservation.
And Vbecer00 at Reconciliation Ecology also touches on the issue of how you get people to care in his/her post on, well, just about every issue in conservation — why do it, how to do it, and how to make it work.
Local: Join Dave Bonta at Via Negativa for a walk in the snow in Plummer's Hollow, and benefit from his sharp eyes. The man knows his neighbourhood, and his shrews.
Or, you could visit Wayne at Niches, and read his reports on the effects of heavy rains on the creeks on his property in Athens, Georgia.
And finally….
Personals: Johan Stenberg is in Sweden, feeling lonely. Cheer Johan up and join his journal club on insect-plant ecology, at (where else but the) Insect-Plant Ecology blog.
So there you have it. Oekologie — opening your minds, grossing you out, winding you up, bringing you together. Thanks again, and be sure to check out the next edition in a month's time on the Behavioral Ecology Blog.
We are family
This week's Nature is a special issue for Linnaeus' 300th birthday, and I've got a feature($) in it looking at what genomics has done for the Linnaean project, in terms of working out the tree of life (and what evolutionary biology can do for genomics). The field is called phylogenomics. One of the surprising things I found when researching this was how uncertain things still are - we have no idea how many of the animal phyla relate to one another, for example.
I'm also talking with Henry Nicholls and Kerri Smith about this on the Nature podcast, recorded at the Natural History Museum in London. Henry has a feature about Linnaeus' raccoon, and has achieved full-spectrum science media dominance by also having a feature($) on metagenomics in today's New Scientist.
Jonathan Eisen's blog is a good place to find out about both phylo- and metagenomics.
I'm also talking with Henry Nicholls and Kerri Smith about this on the Nature podcast, recorded at the Natural History Museum in London. Henry has a feature about Linnaeus' raccoon, and has achieved full-spectrum science media dominance by also having a feature($) on metagenomics in today's New Scientist.
Jonathan Eisen's blog is a good place to find out about both phylo- and metagenomics.
Tuesday, March 13, 2007
A quick toot on my own trumpet
Library Journal has just named ITBOAH as one of the best science books of 2006. Picket your local college or public library now, demanding that they buy at least one copy.
Beard-stoking
The Scientist has a big ol' article, with a fine typo in the last paragraph, on West, Brown, Enquist and their metabolic theory. It's particularly good on recent historical and biographical detail, although a little sketchier on how the idea works, and what else it might apply to besides metabolism.
And I would take issue with the statement that temperature is a "variable necessary to explain the 3/4 scaling of metabolic rates across organisms". It's not, it's an additional variable that explains some of the variation in metabolic rates (between say, reptiles, birds, and mammals, all of which have different body temperatures) not accounted for by size-based 3/4-power scaling.
The article also shows how some of the disagreements about the theory come from differing expectations and goals. WBE are after a theory that gives an abstract, approximate, first-order account of the underlying structure of organisms and ecosystems.
Confronted with Helen Muller-Landau's data on forest population biology that contradicts their predictions they say, well, ok, it shows something else must be going on. Much as, if you see a planet that doesn't follow its predict orbit, you look for something else influencing it before you junk gravity (not that I am saying metabolic theory is as well-established as gravity). Muller-Landau and others, however, see deviation as disproof.
It's a difference partly of philosophy. But it also shows the genuine uncertainty about when you decide that just because a theory can't predict everything doesn't mean it's wrong (as Michael Ruse has written, natural selection's failures are a sign of its strength), and when you decide it's wrong.
WBE's metabolic model is too powerfully predictive, and its foundations make too good sense, to be junked yet. In fact, it seems to be popping up more and more - I have recently spoken to fisheries and foodweb researchers who are using it.
I would also say that people tend not to change their minds, regardless of what data or theory say. A scientific field's centre of gravity depends on when people retire and who gets their job, as much as it does on dialectic.
(The Scientist has published a couple of previous things on metabolic scaling and so on: here and here.)
And I would take issue with the statement that temperature is a "variable necessary to explain the 3/4 scaling of metabolic rates across organisms". It's not, it's an additional variable that explains some of the variation in metabolic rates (between say, reptiles, birds, and mammals, all of which have different body temperatures) not accounted for by size-based 3/4-power scaling.
The article also shows how some of the disagreements about the theory come from differing expectations and goals. WBE are after a theory that gives an abstract, approximate, first-order account of the underlying structure of organisms and ecosystems.
Confronted with Helen Muller-Landau's data on forest population biology that contradicts their predictions they say, well, ok, it shows something else must be going on. Much as, if you see a planet that doesn't follow its predict orbit, you look for something else influencing it before you junk gravity (not that I am saying metabolic theory is as well-established as gravity). Muller-Landau and others, however, see deviation as disproof.
It's a difference partly of philosophy. But it also shows the genuine uncertainty about when you decide that just because a theory can't predict everything doesn't mean it's wrong (as Michael Ruse has written, natural selection's failures are a sign of its strength), and when you decide it's wrong.
WBE's metabolic model is too powerfully predictive, and its foundations make too good sense, to be junked yet. In fact, it seems to be popping up more and more - I have recently spoken to fisheries and foodweb researchers who are using it.
I would also say that people tend not to change their minds, regardless of what data or theory say. A scientific field's centre of gravity depends on when people retire and who gets their job, as much as it does on dialectic.
(The Scientist has published a couple of previous things on metabolic scaling and so on: here and here.)
Wednesday, February 28, 2007
A GUT of ecological scaling?
OK. I'm not going to pretend that I grasp the details of this, but here goes.
A recent paper in Physical Review Letters by Jayanth Banavar et al. presents a general theory of (macro)ecological scaling.
That is, they offer a common explanation for patterns such as that between the area of a place and the numbers of species that live there, area and total biomass, the number of organisms and species of different sizes, the maximum body size of the biggest species in an ecosystem (see here for another view of maximum carnivore size), and relative abundance — the spread of rare and common species.
All these scaling patterns seem to follow power laws, at least over partially. That is, they take the form y=ax^n, and plot as straight lines on a log/log graph.
Here's the abstract:
As far as I can tell, Banavar et al. present a scaling hypothesis, based on a probability distribution of the mass and abundance of different species. Using this, and a set of reasonable assumptions (such as, that an ecosystem's total population and mass is proportional to its area) they derive the relationships described from a single starting point.
Blimey. If all these things can be brought under the one roof — this is the first such attempt that I know of — that's a big deal, I think. These are fundamental ecological parameters. Together, they pretty much sum up most of the questions that community ecology seeks to answer. Even the metabolic ecology models of West et al. (with which I am more familiar) have steered clear of tackling the relationships between species diversity and area, and between body size and diversity and abundance.
But, although much of the criticism of metabolic ecology focuses on its generality, Banavar and his colleagues have an interesting history of seeking yet more general models for the scaling of metabolic rate with body size. Banavar has also worked with Steve Hubbell to develop the neutral ecological theory. It's interesting that this is in PRL. I wonder what a biology journal would have made of it.
Thanks to Phil Ball for bringing this to my attention. I think. If anyone has any thoughts on this, I'd love to hear them.
A recent paper in Physical Review Letters by Jayanth Banavar et al. presents a general theory of (macro)ecological scaling.
That is, they offer a common explanation for patterns such as that between the area of a place and the numbers of species that live there, area and total biomass, the number of organisms and species of different sizes, the maximum body size of the biggest species in an ecosystem (see here for another view of maximum carnivore size), and relative abundance — the spread of rare and common species.
All these scaling patterns seem to follow power laws, at least over partially. That is, they take the form y=ax^n, and plot as straight lines on a log/log graph.
Here's the abstract:
Scaling provides an elegant framework for understanding power-law behavior and deducing relationships between critical exponents. We demonstrate that scaling theory can be generalized to develop a framework for the analysis of diverse empirical macroecological relationships traditionally treated as independent. Our mathematical arguments predict links between the species-area relationship, the relative species abundance and community size spectra in excellent accord with empirical data.
As far as I can tell, Banavar et al. present a scaling hypothesis, based on a probability distribution of the mass and abundance of different species. Using this, and a set of reasonable assumptions (such as, that an ecosystem's total population and mass is proportional to its area) they derive the relationships described from a single starting point.
Blimey. If all these things can be brought under the one roof — this is the first such attempt that I know of — that's a big deal, I think. These are fundamental ecological parameters. Together, they pretty much sum up most of the questions that community ecology seeks to answer. Even the metabolic ecology models of West et al. (with which I am more familiar) have steered clear of tackling the relationships between species diversity and area, and between body size and diversity and abundance.
But, although much of the criticism of metabolic ecology focuses on its generality, Banavar and his colleagues have an interesting history of seeking yet more general models for the scaling of metabolic rate with body size. Banavar has also worked with Steve Hubbell to develop the neutral ecological theory. It's interesting that this is in PRL. I wonder what a biology journal would have made of it.
Thanks to Phil Ball for bringing this to my attention. I think. If anyone has any thoughts on this, I'd love to hear them.
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