Archive for March, 2009

What’s sexier than sex and warfare? Taking the “arms race” one turn too far.

Wednesday, March 25th, 2009

Talk about sexy science. How could any science be any sexier than sexual selection?

Then combine sexual selection with “nature’s arms race,” and what do you get?  Science so titillating that even a seasoned science journalist might get a little…carried away.

This was the only explanation I could contrive yesterday morning after I read Nicholas Wade’s latest contribution to the New York Times Tuesday Science section. Only last week I posted about the importance of the arms race analogy to my dissertation research on the history of coevolutionary research. So I was very excited to see Wade’s piece, “Extravagant Results of Nature’s Arms Race,” gracing the cover of the Science Times.

Sexual selection is not really my bag—the evolutionary “arms races” that I write about are between hungry herbivores and unpalatable plants, not males of the same species. But the general concept is the same: offense and defense is heightened over many generations as a result of natural selection for the best-fed herbivore, or the least palatable plant, or, in the case of the sexual selection, the most successful (read: sexiest) male.

Sexual selection is a special case of natural selection where the most successful features do not always seem obviously adaptive. Take the classic example, the peacock’s plumage. Its lavishness makes no sense when you imagine the peacock trying to outrun a tiger. What can be more evolutionarily important than avoiding being eaten? Being sexy, of course. At some point in evolutionary history, females developed a preference for gaudy tails, and since the males with the gaudiest tails were the ones getting the action, more pretty boys in the next generation had gaudy tails. And so on– you get the picture.

This “female choice” type of sexual selection does involve an “arms race” of sorts: Peahens’ preference for gaudy tails escalates even as the gaudiness of male tails escalates—female preference and male success mutually reinforce and drive each other to greater extremes.

But invoking the “arms race” seems a lot more convincing when you are talking about out-and-out evolutionary combat. The second type of sexual selection, “male-male competition” is all about the escalating evolution of better and better weapons. In some species, males actually fight for sex, as with these male elephant seals battling for control of a harem of females. But in other species, it’s enough to look big and scary, to intimidate the other guy before he even tries to fight you. If your antlers are large, you might fight other males and win. But if your antlers are humongous?  You could be king of the lek without ever having to tangle. Possible bonus: Your “armament” may also serve as an “ornament” if females find your big antlers sexy. These University of Minnesota researchers found that lion’s manes did double duty, attracting females AND intimidating other males.

Wade’s Science Times article profiled a recent review paper on the diversification of male animal “weaponry” by Douglas Emlen at the University of Montana.

Dung beetles -- from a nice Discover Mag blog posting about the evolution of female dung beetle horns.

 

For your viewing pleasure, the piece focuses especially on the dramatically beautiful “horns” of dung beetles. And, as in most profiles of sexy science, Wade could not resist taking the next step, pushing toward that ultimate climax of sexy science.

What’s sexier than sex and warfare?

Sex and warfare and humans, of course:
“People have pathetically puny teeth and claws compared with the armaments of other dominant species. This is a sign not of pacific intent but of the fact that they manufacture their weapons.”

In other words, the “arms race” is more than just a metaphor that allows us to comprehend the evolution of elaborate organic weaponry on our own terms, those of technological weaponry. It’s an analogy between human and nonhuman evolved features.

If you read what I wrote about analogies last week, you’ll know that when evolutionary biologists posit such an analogy, they are claiming that evolved tusks and manufactured guns were generated in response to the same selective pressures. They have different evolutionary histories–in this case, the difference is even more extreme, since one has a biological evolutionary history and the other has a cultural evolutionary history.  But they are analogous because they share an adaptive function.

I am most fascinated by analogies like these, which effectively blur the boundary between biological evolution and cultural evolution. But it’s not just the boundary between biology and culture that becomes a bit blurry here. Wade interviewed a primatologist who claimed that it’s “very reasonable to assume that, as humans evolved and our culture became more complex, skills in tool making or other cultural behaviors took over from anatomical traits as ‘markers’ of a male’s competitive skill.”  In other words, the proposed mechanism for such a shift is also kind of hazy.  Claiming that cultural evolution just “took over” from biological evolution is not exactly a substitute for a testable hypothesis.

In any case, whether or not you think this is a reasonable assumption, you have to admit that it’s very compelling. Analogies are compelling—that’s why they are so useful.  They motivate us to make analytical leaps that, in the best of scientific circumstances, may also be empirically verified.

Sometimes those gravity-defying leaps also defy logic, however. Even a seasoned science journalist like Nicholas Wade may be seduced by sexy analogies into making such a logic-defying leap.

Wade analogizes between the organic “weaponry” featured in Dr. Emlen’s paper and a samurai helmet or a crossbow. So far, so good—these could make sense within the context of sexual selection.

Then, suddenly, Wade leaps into the geopolitical domain of the “menacing tanks and rockets that paraded through Red Square in Moscow in the days of the Soviet Union.” This is where the allure of the arms-race analogy becomes dangerous. Was the Cold War a result of sexual competition? Is the “the advent of chemical, biological and nuclear arsenals” really relevant to a piece on male-male competition?

The arms-race analogy has been scientifically productive, helping biologists imagine a series of evolutionary interactions that mimic the military escalation of the Cold War.  But when it leads us to relate sexual selection to global politics, it has probably overreached the limits of its utility. And when this overreaching happens on the cover of the Science Times, we must take pause.

Evocative analogies are powerful tools and—just like that nuclear arsenal—they should be used only with the greatest of caution.

The confusion over funding basic science is about much more than an ignorant Canadian chiropractor.

Thursday, March 19th, 2009

Over the last few days Canadians have become positively apoplectic over the comments of their Minister of State for Science and Technology, the Honorable Gary Goodyear.  It’s really hard to believe how this whole affair began.  In an interview with The Globe and Mail (a Torontonian newspaper that is distributed nationwide), Goodyear was asked whether or not he believes in evolution.  To which he replied, “I’m not going to answer that question. I am a Christian, and I don’t think anybody asking a question about my religion is appropriate.” 

When I first read this, I thought there must be some mistake in the transcript.  They couldn’t possibly have asked him a question about evolution and received an answer about religion, right? Apparently, however, this is exactly what happened.  After which Goodyear insisted that his attitude toward evolution is “irrelevant” to his position in the Canadian government.  As if the sudden insertion of religion into the conversation hadn’t already demonstrated that relevance was—-well—-irrelevant?

Of course, Goodyear’s attitude toward evolution really is relevant to his post when scarce funds are being divvied up between cash-starved research agencies.  Society grants money to the research projects nearest and dearest to its heart.  This is true on a large scale, as in the case of widespread enthusiasm for medical research, and on a small scale, in the case of individuals making case-by-case granting decision.  In any case, it’s hard to imagine how Goodyear could even assess the relative merit of different research programs, since he is not trained as a scientist and has likely never performed any kind of research himself. He is a chiropractor.  According to the original Globe and Mail piece, his qualifications for steering Canada’s science policy include undergraduate science courses and his high school education in “welding and automotive mechanics.”

In case the suspense is just killing you, let me relieve your mind: In a follow-up interview with the local CTV, Goodyear clarified that he does believe in evolution.  He then demonstrated that he actually has no idea how biological evolution works.  Evolution happens “every year, every decade” he claimed, in response to such things as walking on pavement or wearing high heel shoes.  With a lack of biological knowledge and a lot of imagination, anything is possible, I guess.  In this scenario, sore feet from bad footwear results in lower reproductive success?  OK, maybe.  Then footwear shifts the genetic makeup of the human population within the span of a year?  Never.

While I find Goodyear’s ignorance unnerving, the journalist’s response was far worse.  She didn’t even call him on his imaginary version of “evolution.” What’s the point of asking Goodyear such a question if you can’t even suss out a nonsensical answer?

I guess I should not be surprised that journalists deep into the Goodyear drama really don’t understand the science that’s at stake. Even in formulating arguments in support of so-called “basic science” research, journalists get it wrong.  Here is an excerpt from the original Globe and Mail article on Gary Goodyear:  “Many scientists fear 10 years of gains will be wiped out by a government that doesn’t understand the importance of basic, curiosity-driven research, which history shows leads to the big discoveries. They worry Canada’s best will decamp for the United States, where President Barack Obama has put $10-billion (U.S) into medical research as part of his plan to stimulate economic growth.”

History does, indeed, show that “basic, curiosity-driven research” can lead to “the big discoveries.”  The 20th century left us with some neat stories about basic research leading to powerful technological application.  These stories begin with that esoteric, ivory-tower kind of science, like theoretical physics or the search for the structure of DNA, and end with big explosions or tools for directly manipulating genetic material.  None of them begin with $10 billion to the U.S. National Institutes of Health (NIH) for medical research.  Medical research is not basic research—it is research driven by an explicit goal, by the desire to solve a specific kind of problem, not by curiosity.

Many Americans will probably be pretty excited that U.S. policy is, for the first time in almost a decade, being held up as an aspirational standard. A piece in The Globe and Mail on the same day pointed to Obama’s economic stimulus package as an exemplar of investment in scientific innovation.  Don’t believe the hype, though—there isn’t much good news for so-called “basic science,” even in the vaunted economic stimulus package.  The U.S. stimulus package does, indeed, contain a large amount of money for the NIH.  In fact, the much-touted $10 billion for medical research is being granted to the NIH in addition to the approximately $29 billion that it already receives on a yearly basis.  In other words, the NIH will get about $40 billion from the federal government in 2009.

By contrast, the National Science Foundation (NSF), established just after WWII to support basic research, that elusive brand of research that doesn’t try to sell you a panacea for all of society’s woes, is receiving $6.5 billion.  That doesn’t sound so bad. Until you learn that this is the NSF’s entire budget for the year.  And last year it received $6 billion.

OK, so my husband, who is one of these basic scientists (He studies the evolution of fungi.  No, he does not study possible anti-cancer agents found in mushrooms.  Nor the bioremediation of toxic-waste spills by fungi.  He studies what happened to fungi thousands of years in the past.) interjects here: “Think of how many more proposals the NSF will be able to fund with an extra half a billion dollars!”  Granted.  But proportionally speaking, well, I think you see my point.

It’s intuitively appealing to imagine that research aimed directly at finding the next miracle cure yields more bang for our scanty bucks than basic biological research.  But science policy should be steered by something more substantial than intuitive appeal.  The research projects funded by the NIH are, by and large, not exploratory.  They will likely break no new ground, and it’s misleading to claim that they will somehow lead to the next big “discovery.”   To the contrary, medical research usually builds upon ground broken by biologists who were not even hoping for a medical breakthrough, biologists funded by agencies like the NSF or, in the Canadian case, the Natural Sciences and Engineering Research Council (NSERC).

The honorable Gary Goodyear has rightly become a symbol.  But rather than a symbol of broad societal ignorance of evolutionary theory (which, don’t get me wrong, he is), I see him more as a symbol of the confusion over notions of “basic research” and technological innovation.  Funding medical research is essential.  But investment in basic research, in building knowledge even when its application is not immediately obvious, is equally essential.

(For an interesting take on how to spend these billions of research dollars, check out this week’s guest columnists on Olivia Judson’s NYT blog.  Definitely an interesting proposal–again, like most basic research, though, an investment in the future.  There’s no instant gratfication in the practice of science.)

Make an analogy between humans and cockroaches and then read this posting.

Friday, March 13th, 2009

At this moment in my dissertation work, I am transcribing my two-hour interview with ecologist Daniel H. Janzen.  In early December 2007 I flew to Philly and stayed there for one night, interviewing Janzen in his office at the University of Pennsylvania just 6 hours before I flew back to Toronto.  Clearly, I have waited far too long to transcribe the interview, which is typical of me.  I am always excited to rediscover what I learned during an interview.  Somehow I manage to forget almost everything we discussed in the minute after an interview ends—it’s as if my intense relief that it’s over triggers some sort of spontaneous amnesia.  So there are always many pleasant (and some excruciatingly embarrassing) surprises awaiting me.  But I find the process of the transcription totally grueling.  I really try to get every “um” and “ah” and grammatically disastrous sentence recorded for posterity, and this requires a lot of rewinding.  In the case of Janzen, who sprints from topic to topic in a rusty Minnesotan accent, rarely pausing for the insertion of a period or comma, my rate of transcription slows down considerably.  Not to mention that there are so many more words per minute in this interview.  I am 1 hour and 36 minutes into this interview and I have a 15-page transcript already.

There is a lot of good stuff here.  There’s an absolutely incredible story about botanist G. Ledyard Stebbins, who purportedly slept through Janzen’s thesis defense, but woke up just in time to compare the ants that Janzen studied to the chemical defenses that other plants produce, which protect them against attack by herbivorous insects.

At that moment, Stebbins gave Janzen what would become one of his most persuasive analogies.

My (point-and-shoot) pics of ant acacias from Santa Rosa National Park in Costa Rica (2006)

My (point-and-shoot) pics of ant acacias from Santa Rosa National Park in Costa Rica (2006)

Some background will help you understand this analogy.  Janzen’s dissertation research in Mexico exhaustively detailed the mutualistic relationship between “bull’s-horn” acacias and acacia ants.  As a graduate student in entomology at Berkeley, his first notion was just to study these ants—why were they so bizarrely fond of these prickly acacia trees?  It was by chance, or at least “serendipity,” that his attention shifted to the relationship between the ants and the acacia tree.  In his thesis, he concluded that there is a real mutual reliance between the two species.  The ants cannot live without the acacias: they take shelter and breed in the acacia’s oversized thorns and feed from the plant’s nectaries and Beltian bodies (little nutritive tabs that grow at the leaftips of the acacia).  Conversely, acacias that grow without a resident ant population rarely thrive. Without the ants to fight off other insects and the choking lianas that like to drape themselves across other plants, the acacia falls prey to both herbivory and competition with other plants.

Now, Janzen was not, by any means, the first to turn his attention to this surprising relationship.  Thomas Belt, a 19th-century British mining engineering who worked in Nicaragua for years, called the ants a “standing army” that defends the acacias against their enemies.   Harvard entomologist William Morton Wheeler challenged the claim that the ants were protecting the acacias, writing in the early 20th century that plants needed ants like a dog needs fleas.  Strong words, gentleman!  A raging academic debate that did not subside till Dan Janzen’s paper, “Coevolution of Mutualism Between Ants and Acacias in Central America,” published in the journal Evolution in 1966.

One of the things I’ve always loved about evolutionary biology is the evocative language that biologists use to describe processes and relationships.  Are the ants a “standing army” or a pack of voracious sap-sucking fleas?  Gives you two pretty distinct ecological pictures, right?

The study of coevolution between plants and insects has been built upon suggestive language like this.  This was a field that came into being during the Cold War, so who could really resist using the term “arms race” to describe the back-and-forth evolutionary responses between plants and insects?  Plants escalate their toxic biochemical defenses against hungry herbivorous insects, and insects escalate the tools they use to overcome those defenses.

So, what does it mean to claim that acacia ants function just like the chemical defenses used by other plants to fend off the insects that would eat them?  First, this analogy crosses categories: the ants, organisms in their own right, become (merely?) evolutionary adaptations of the acacias.  The ants are, Janzen would claim, an extension of the plant’s genome—in the same way that human technologies are extensions of our genome (which he also claims).  In essence, then, the ants become an adaptive technology.

But an analogy always operates in two directions.  The reciprocal effect is to grant the chemicals produced by plants a new identity.  The best analogies (just like the best metaphors) associate entities that seem, otherwise, completely dissimilar.  In this case, the analogy between ants and plant chemicals breaks a long-accepted boundary between what animals can do and what plants can do—or, rather, what plants can’t do, passive pieces of green furniture that they are.

I mean, when we talk about animals, we use active verbs.  We see them causing things to happen, acting—in short—with agency, if not intentionality.  Plants, on the other hand, when they’re not simply invisible, don’t tend to act.  They don’t move, they have no sensory organs.  Even when we see them, we don’t think of them as agents.   Even when a plant has an effect on its environment, it appears somehow passive, and the effect is often considered a by-product of some other more planty function.

Coevolutionary analogies, by contrast, make plants and animals equal partners.  More accurately, they’re adversaries. And plants, so long seen as the wallpaper of the world, suddenly become embattled veterans of an ancient chemical war with animals.

This kind of transmission of meaning and agency between plants and animals has real effects on science (this is one of the themes of my dissertation).  It’s one reason that I became so interested in Janzen.  The man analogizes like it’s going out of style.

More importantly, he is very careful to distinguish between “analogy” and “metaphor.”  Janzen does not speak in metaphors, because metaphors make comparisons that could not be literally true.  If he makes a comparison between, say, armyworms gobbling up an entire field of corn and Germany invading Poland, he does not mean this comparison metaphorically.  To him, hungry caterpillars and power-hungry humans are the same thing. The entities interacting are unimportant: locusts or leopards, hummingbirds or humans, it doesn’t matter—only the interactions themselves are important.

Janzen describes this as a fundamentally ecological perspective on the world, but I see it as a fundamentally evolutionary perspective, instead. In evolutionary biology, limbs or organs are analogous when they perform the same biologically adaptive function but have different evolutionary origins.  When Janzen draws an analogy between human warfare and plant-insect warfare, this is also what he means: same adaptive function, different evolutionary origin.

Ants or wild parsnips, humans or cockroaches—we might organize them into different categories, but evolutionarily, they are all subject to the same forces.  It’s part of what gives evolutionary biology its explanatory power.  And also, let’s face it, what makes it so darn fascinating.

This is one good-looking cockroach, right?  Also from Santa Rosa National Park.

This is one good-looking cockroach, right? Also from Santa Rosa National Park.

An example of how much irony you can pack into a story that ends with an iron padlock (plus a pun).

Monday, March 9th, 2009

When Bryn finally got the collection and export permits, it all happened so fast.  One minute we were eating our huevos fritos in Orosi, and the next, driving back to San Jose.  After some navigational hijinks (Was it Calle 11 y Avenida 1 or was it Calle 1 y Avenida 11? It’s the latter, by the way, just in case you are ever searching for the Ministerio de Ambiente y Energia. But since nobody living San Jose even knows what the streets are named, good luck to you.), we had the permits in hand.  After two months of lead time and four days in Costa Rica just wandering the countryside and waiting for these permits, it was like this: We walked into a nondescript office building, were basically handed a few sheets of paper and Bryn’s “Pasaporte Scientifico,” and we walked out 5 minutes later, slightly stunned.

Parque Nacional Tapantí-Macizo la Muerte

Parque Nacional Tapantí-Macizo de la Muerte

Parque Nacional Tapantí-Macizo la Muerte

Parque Nacional Tapantí-Macizo de la Muerte

The following day we finally entered Parque Nacional Tapantí-Macizo de la Muerte.  This park, which remains relatively wet even during the dry season, is the entire reason that we stayed in Orosi.  But this was our first visit to Tapantí.  There was simply no reason to even enter the park before we had the collection permiso (especially considering the $10 per gringo entrance fee—it’s less than $1.50 for Costa Ricans).  After so much anticipation, our first day in Tapantí was anticlimactic.  OK, it was far worse than anticlimactic.  Yes, we did seek out the lluvia, but did we ask for it to pour on us the entire day?  And the miserable rain-drenched hiking really just added insult to injury:  We only made 7 collections the entire day.

Now, we know rain and mud.  Hiking at Los Cedros in the Ecuadorian highlands during the rainy season pretty much requires a complete daily hose-down.  My rubber boots are still full of this persistent dust, the remains of mud built up over the course of weeks, which sifted into the crevices of all my belongings.  But at Los Cedros I wore rain pants and wellies and a vinyl poncho. At Tapantí, in contrast, thanks to the concerted efforts of quick-dry field pants, my otherwise lovely Asolos, and an aging rainjacket, I became more thoroughly saturated with water than ever before in my life.  Somehow we pushed past the limits of Gore-Tex-lined hiking boots until our feet came to resemble ungodly crosses between a mud-puppy and a naked mole rat.

Under these conditions, the most interesting trail also became the most treacherous. El Sendero Natural Arboles Caidos, or the Natural Trail of the Fallen Trees, had two attractions for us.  Many of the trails at Tapantí have been constructed for bird watchers and casual hikers.  They are relatively flat and short and lead to a lookout or small river.  By contrast, the fallen tree trail climbs steeply up into the forest, getting closer, we hoped to those elusive oak trees.  And, for people who hate to backtrack (us), hiking (driving, canoeing, any kind of transportation) in a loop is totally ideal.

El Sendero Natural Arboles Caidos, Tapantí

Did I mention that the trail climbed steeply, however?  Let’s say, actually, that while you, the hiker, are climbing steeply, most of the trail is actually exiting the forest in the opposite direction, in a sizable stream that mounts a pretty decent catarata at times.  Conclusion: Naming a trail for its fallen trees is actually an effective way to abdicate responsibility for trail maintenance.  A hiker expects erosion and tangles of brush on a trail named for destruction, right?

Calostoma cinnabarina

Calostoma cinnabarina

All in all, however, we did make one very nice find. A totally bizarre bolete (Yes–this is good!  A mycorrhizal fungus!), Calostoma cinnabarina (often called the “gelatinous stalked puffball”), which looks as if it is covered in slimy tomato seeds.  However, by Bryn’s calculations, which weigh the cost of a research trip against the number of collections made, this bolete ought to be covered in 24-karat gold leaf, not tomato-seedy slime.

dscn0519

So, what next?  We decided to enter the park from the other end, at a biological station called La Esperanza, where the elevation is considerably higher.  This entrance, which Roy Halling showed Bryn some years ago, is unsigned at the Inter-American highway and lies at the end of a pretty nondescript, rough country road running through an extremely tiny town full of very friendly people (and at least one very cute little cow).

dscn0510

Fortunately, my husband has a photographic memory when it comes to the location of mushrooms, as well as an internal compass to beat the band.  I’m not giving too much of the story away when I reveal that, in addition to these fine qualities, he also appears to have some surprising and extremely useful skills that involve the artful combination of a padlock and bobby pin.

Driving into the park on this gorgeous morning, we happened to pass a Ministerio de Ambiente y Energia truck driving in the opposite direction.  Myself, I took this as a promising sign that we were moving in the right direction.

dscn0466dscn0473

When we arrived at the entrance, however, it became clear that the truck also represented the departure of the ranger.  No, we did not break into the park.  Luckily for us, the ranger had left the gates wide open, so we simply drove up the road to a large grove of alder, where we started our mushroom search.  Over the course of the morning, we worked our way back down the road, enjoying a really beautiful sunny day below the aforementioned oaks.

Just after lunch, however, we were near the station again, so we decided to go chat with the ranger.  This was the moment that we discovered ourselves to be locked into Parque Nacional Tapantí-Macizo de la Muerte.

For days we had been trying to gain entry and now, well, it appeared that we weren’t going to be leaving it anytime soon.

It was 2pm, so we had about 4 hours till sunset.  It looked like we would be hiking out of the park, so I wanted to make sure that we got a jump on the darkness, just in case it proved to be a struggle to contact someone who could also get our car out.  Bryn had other ideas.

We’ve been here before.  I have a lot of faith in my husband, in many respects, but as a lock-pick, he has never displayed much talent.  But when he said: “Do you have anything I could use to pick this padlock?” I just dug out a bobby pin and shut my mouth.  It was an opportunity to lay in the sun for a little while and gear up for the long hike back to the Inter-American.

Not five minutes later, however, there was a loud clang.  He truly did pick that lock.dscn0508

Art or luck?  More likely that double-layered luck again—the fortuitous convergence of some preparation and that telling “Made in China” stamp on the lock’s iron backside.  In any case, we proved to the bureaucratic administration of Costa Rica’s natural resources that we won’t be kept out of the park—and we sure as heck will not be kept in either.

Yep, we showed ‘em.  Even if neither of us quite had the vocabulary en Español to explain the lock-picking story to the ranger when he reappeared later that day.