Archive for the ‘history of science’ Category

The Sons of Scientists

Wednesday, December 18th, 2013

I once interviewed a prominent ecologist for my doctoral research, whose partner told me, “You know, these [prominent ecologists], they all have really strong mothers, influential women that encouraged them to explore nature.” I liked this theory, though I didn’t have much proof to support it, so I thought better of mentioning it in my dissertation.

I bring this story up today only because I want to completely disavow any sort of similar claim that you may or may not imagine I am making with my title. In fact, once I realized that this was the post that I was writing, I was slightly embarrassed. You see, by pure chance, I have researched the work of a lot of scientists with sons.

The first was Carroll Williams, an insect physiologist whose work I ran across early in my doctoral career. In leading his lab at Harvard in the 1950s, he solved a small scientific mystery, a sort of biochemical whodunit. Whole generations of his insect subjects were mysteriously dying. They grew and grew, but never developed into mature adults, remaining outsized juveniles, unable to reproduce.

Williams (left) isolating the newly discovered "natural insecticide" from a slurry of paper towel.

His sleuthing led him finally to the paper towels he used to line their petri-dish homes. But when he wrote to the manufacturer to ask for the makeup of the towels, the answer he received was simply this: “paper pulp.” Not one to be disheartened, Williams hypothesized that the trees used to make the pulp must produce chemicals that acted as hormone mimics, disrupting the development of his insect subjects—compounds that had likely evolved in response to insect feeding, as a form of “natural insecticide.” He even managed to isolate this substance and verify that it was responsible for the death of his experimental insects.

Williams’ fascination with “natural insecticides” was shared by the coevolutionary theorists at the core of my Ph.D. research, so when I learned that the Harvard University Archives held his collected papers, I was pretty excited to get a look at them. Typically, I seek out a scientist’s children when it proves impossible to locate the scientist’s papers in any archive, in the hopes that their family has stashed away boxes of letters and research notebooks in a nice dry attic somewhere. But in this case, while Williams’ papers were already conveniently deposited in an archive, I needed special familial permission to gain access to them. Luckily, I had the internet to help with own my sleuthing, and I tracked down one of Williams’ sons, Roger, who kindly sent Harvard notice that I could see his father’s papers.

Another scientist whose son I have contacted is Gottfried S. Fraenkel—again, an insect physiologist and a near contemporary of Williams. Fraenkel was far more interested in insect nutrition than in hormones, however. In fact, it was his interest in nutrition that brought me into contact with his son, Gideon, who has had a career as an organic chemist himself. I was revising a paper about Fraenkel the senior, starting with his work in the UK in the ‘30s and ‘40s on the molecules of nutrition. Later Fraenkel moved to the US, where he began to hypothesize about the evolution of insect feeding choices. But in 1946, a couple of years before he left the UK, Fraenkel contributed to a Fabian Society tract on agriculture, arguing vehemently against the capitalist conspiracy to foist white bread on an unsuspecting public. Using his favorite research subject, the confused flour beetle, Fraenkel had demonstrated that refined grain was nutritionally deficient. Even more significantly, he found that refortifying the bread with the nutrients removed in processing still produced a nutritionally inferior product—a very nice story in light of growing scientific consensus that vitamin supplementation may be fairly worthless (or worse!).

In other words, Fraenkel suggested—back in the 1940s—a fairly holistic concept which has seemed increasingly convincing in recent years: nutrients are healthful in the context of food, but a disembodied molecule (even when added back in to food) is of dubious value. The reductionist reliance on nutrients has not attracted a ton of media attention, though Michael Pollan wrote a nice piece on this topic some years ago (and I loved the molecular banana cover image for this piece!). Expect more coverage now, however; just today, NPR has rounded up recent research on the value of vitamins, which is well worth checking out.

But back to the sons of scientists! When I first wrote the paper on Fraenkel, I did not realize that he was instrumental in naming brown bread the National Loaf of Great Britain. In other words, there was a UK-government mandated insistence on whole wheat as early as the 1940s! (Yet, my kid’s nursery today serves white toast to preschoolers who otherwise would not even know that such an abomination exists…) And I only learned about this thanks to Gideon Fraenkel, who actually wrote a letter to the New York Times on the subject.

One son of an scientist, I am chagrined to admit, may have been unhappy with how I portrayed his father. Warm and welcoming when I was viewing his father’s correspondence, I never heard from him again after sending him a draft of the paper that examined some of his father’s work. This is certainly the biggest danger in interacting directly with a subject’s children; they naturally want to see their parent’s work only celebrated.

Don Eyles Sr. in Malaysia with the family's pet gibbon, Wah Too. Image courtesy of Don Eyles Jr.

Most recently, when I traveled to Boston for the 2013 History of Science Society meeting, I was lucky enough to meet with the son of one of my current subjects. Don Eyles was a parasitologist working for the NIH in 1960 when he was accidentally infected with a malaria parasite that had been isolated from a Malaysian (or, rather, Malayan, at the time) macaque. Though the infection of humans with monkey malaria had, in truth, been known for decades, malariologists regarded the possibility as so remote that used little caution with the monkey malarias, even when working with heavily infected mosquitoes. Eyles was one of the first to learn that this was a mistake: What seemed like a meaningless mosquito bite while running an experiment became, for him, a case of malaria. And thus ensued three years of intensive NIH-funded lab and field research on a variety of monkey malarias and their mosquito vectors.

Admittedly, when I started searching for the children of Don Eyles, I immediately saw that his son—his namesake, in fact—lives in Boston. Eyles Jr. is an interesting person in his own right, having worked as programmer on the moon mission.  The BBC referred to him as a “Beatnik” who put men on the moon.  And here Eyles has written a paper about technical problems on the mission.

Meeting with him last month, I enjoyed my requisite Bostonian lobster lunch and gratefully received the gift of historical treasures from him.  He lent me a very cool 1966 New York Times Magazine with a cover article on his father’s malaria research project. And he gave me a copy of the memoir of his fascinating mother, Mary Stipe Eyles, who was herself trained as a scientist and taught high school biology for many years. His mother and his two younger siblings were with Don Eyles Sr. when he tragically died of a heart attack in 1963, just as the family was about to return to the US from Malaysia.

Don Eyles Jr. at our seafood lunch meeting.

 

Don Eyles Jr. (who even, by the way, attended my talk at the conference!) promises to put me in touch with his sister, one of the above-mentioned younger siblings, who lived in Malaysia with her family while her father pursued local monkey malarias. Check out photos of the family here.

I may finally have my chance to talk to the daughter of a scientist! And I have no doubt that she will be just as helpful and insightful as the very kind scientists’ sons who have kindly assisted me in the past!

Making the scientist, making the place for science

Wednesday, March 28th, 2012

Sir Joseph Dalton Hooker

 

Kew’s exhibition, “Joseph Dalton Hooker: Botanical Trailblazer,” highlights handsome illustrations and provides a personal and professional cross-section of the making of a Victorian scientific career. But tantalizing morsels hint at tensions between public needs and professional goals in the life of a scientist and in the operations of a scientific institution like Kew, leaving the visitor wanting more.

“Kew is what my father and I have made it by our sole unaided efforts,” claimed Joseph Dalton Hooker in the early 1870s, affronted by a Board of Works proposal to eviscerate the scientific function of Kew Gardens.  The proposal to transfer Kew’s herbarium collections of dried plants to a new museum soon to be opened in South Kensington (now known as the Natural History Museum) was politically framed as an attempt to streamline government-funded institutions and reduce spending. But Hooker saw it instead as a direct attack on his scientific career.

He had strived for decades to support himself through botanical work, making expeditions to the ends of the earth to collect new species of plants for Kew Gardens. Finally, in 1855, his father, Sir William Jackson Hooker, the first director of Kew, was able to hire him as assistant director.  And in 1865, with his father’s death, J.D. Hooker became director himself.  But now, just when he had ascended to the rank that would allow him to shape botany into a properly scientific pursuit, this proposal threatened to turn Kew into a mere pleasure garden, and to turn Hooker himself into a mere public servant.

Of course, ever since Kew was made public in 1841, its director was expected to act, to some extent, as a public servant, assisting horticulturalist and farmers at home and abroad with various botanical conundrums.  Hooker himself became known for his aid in transplanting useful plants to colonial outposts: bringing quinine and rubber from South America to India, and disease-resistant coffee from West Africa to Sri Lanka.  But Hooker believed just as strongly that Kew must serve the needs of botanical science, and to that end the herbarium was essential.

Fortunately, the safety of Kew’s herbarium was secured by 1874, thanks especially to the exertions of that infamous firebrand evolutionist Thomas H. Huxley.  But questions about the Gardens’ function remained.  In fact, while this exhibit largely glosses over the near-catastrophe of the early 1870s, comical illustration from later in the decade arrest the visitor’s attention, depicting Kew Gardens as a place where the enjoyment of the public and the work of scientists directly conflicted.  In 1883, the Gardens began opening at noon; but prior to this shift, an opening time of 1pm prolonged the morning hours that scientists and students could work in Kew, undisturbed by the baser concerns of the general public.  This one extra hour of public access was the hard-won product of at least seven years of public protest, if we are to judge by the date on a large cartoon: Inside the Gardens’ walls the privileged few luxuriate while the rabble pickets outside with signs like “Down with the select arrangement. No peace until satisfied” and “Give the public justice.”  This cartoon, as with other such images in the exhibit, is inexplicably unreferenced, which is a shame, since visitors could better understand the illustrations’ significance with knowledge of their sources.

But Hooker’s place as the gatekeeper of Kew’s scientific reputation was also hard-won and it’s easy to understand his staunch defense of the Gardens as, first and foremost, a place for science.  Both his and his father’s early careers had not been easy, and in building the scientific reputation of Kew, he built himself into a scientist in parallel.  His trips around the world had fed the growing herbarium; according to the exhibit, over his 70-year career, Hooker identified more than 12,000 new plant species. Hooker sketched many of his collections while he was in the field.  It’s wonderful to see the handwritten evidence of fieldwork found in researchers’ field notebooks, and Hooker’s sketches of plants and landscapes are some of the most engaging illustrations in the exhibit, drawing the visitor in to Hooker’s travels.

Using these collections, Hooker also asked larger questions about plants. In 1839, when he was only 22, he set off on his first long voyage, working as the assistant surgeon on an Antarctic expedition (though he preferred, according to the exhibit, his unofficial title of ‘Botanist to the Expedition’).  Observing patterns of similarity and difference between plants found on the continents he visited gave him a lifelong fascination with the geographical distribution of plant species.

In highlighting Hooker’s astute observations of the geographical distribution of plants, the exhibit also presents a rather funny incongruity.  Hooker is credited in one breath with cultivating non-native plants like quinine and coffee in the colonial landscape, and in the next with a prescient understanding of the ecological dangers of non-native species.  In particular, we are told that upon visiting various islands in his travels around the Antarctic, Hooker became aware that non-native species were damaging to their “unique plant communities. These problems continue today with invasive non-native plant species overwhelming natural habitats, pushing some native species to the brink of extinction.”  The irony of this is only heightened by Hooker’s renown for bringing the seeds of unfamiliar varieties of rhododendron back from the Himalayas.  As popular plants in the Gardens, some of these may still be seen today in Kew’s Rhododendron Dell—as well as outside the garden where some “escapees” have come to act “invasively,” and are considered a non-native nuisance.

This apparent contradiction is no mistake—in fact, it reflects a cognitive dissonance that still thrives in biology, where organisms may sometimes be cast as emigrants and other times as invaders, where one moment one is a great success in a new ecological niche and the next a weedy marauder.  The identity that a newly introduced species assumes rests to a large extent on cultural context rather than biological fact—which supports no opinion either way.

To be fair, though, J.D. Hooker’s scientific legacy is felt more in evolutionary biology than in invasion ecology.  Hooker began his 40-year friendship with Charles Darwin just as he was setting off on his Antarctic expedition in 1839.  And by the time Hooker left for the Himalayas in 1847, Darwin had confided in him his developing theory of natural selection.  Thus, on this adventure, Hooker travelled, as a video in the exhibit says, with “a shopping list for Charles Darwin,” acting as Darwin’s eyes and ears in the field. “I congratulate myself in a most unfair advantage of you,” Darwin wrote to Hooker, “viz in having extracted more fact and views from you than any other person.” Considering what it must have meant for Hooker to have the seed of Darwin’s theory already planted in his mind a dozen years before the publication of On the Origin of Species, for him to see the vegetation of the Himalayas through that lens, it’s easy to understand how Hooker’s assistance and—later—his support of natural selection became indispensable to Darwin.

This plaque on the wall of St. Anne's church on Kew Green commemorates J.D. Hooker, who was buried in the churchyard outside.

This is the gravestone for J.D. Hooker and his family--considering that he could have been buried near Darwin in Westminster Abbey, this is pretty understated!

“Joseph Dalton Hooker: Botanical Trailblazer” does a good job of touching on many of the major themes in Hooker’s life and work and it is a worth a visit.  But you must hurry to the Shirley Sherwood Gallery of Botanical Art, for the exhibit closes on Monday 9th April. If you wait till after 31st March, you will also be lucky enough to catch Rachel Pedder-Smith’s awesome herbarium specimen paintings.

 

 

For Further Information:

The exhibit has a very nice little companion volume, which can be purchased at the Kew gift shop, and features a great introduction by historian of science Jim Endersby.  I admit that I have not read his book Imperial nature: Joseph Hooker and the practices of Victorian science, but it looks like within its pages you can find out more about the near-demise of the Kew Herbarium in the early 1870s, a controversy that was named the “Ayrton Affair” after the head of the Board of Works, Acton Smee Ayrton. (The Ayrton Affair was also just one element within the Royal Commission on Scientific Instruction, also known as the Devonshire Commission.)

For more on the history of the Royal Botanic Gardens, Kew, check out their cool historical timeline.

If you would like to learn more about why I put “invasive species” in scare quotes, read out my own article on the subject at The Naked Scientists and check out this 2011 Nature article, entitled “Don’t judge species on their origins,” which you can actually read for free here, thanks to the US Forest Service!

Darwin’s finches – and Darwin’s humans

Tuesday, August 16th, 2011

Darwin gets a lot of credit in biology.  And rightly so, given the sheer quantity of persuasive proofs and fascinating conundrums that he put forth during his career.  This is a man who saw a foot-long nectary on an orchid from Madagascar and asserted the existence, sight unseen, of a moth with a proboscis long enough to reach the nectar at the bottom and pollinate the flower.  Forty years later he was proven correct.  So it is no exaggeration to say that Darwin left a legacy of leads for his intellectual inheritors, many of whom are fond of claiming Darwin not only as an ancestor but also as the source of all of the best ideas and problems in evolutionary biology to this day.

The Galápagos Islands have long been the scene of such claims. Darwin travelled around the world from 1831 to 1836, but he spent barely over than a month exploring the Galápagos.

Map of the Galápagos Islands, from Darwin's Journal of Researches, published in 1839.

Even so, this volcanic archipelago off the coast of Ecuador became one of the iconic locations of Darwin’s Beagle voyage.  Because of the attention that Darwin drew to the evolutionary dynamics of the Galápagos, the islands became a so-called “natural laboratory,” where biologists have gone for generations to watch evolution in action.

In this month’s issue of Evolution, researchers led by Fernando de León from McGill University in Montréal chose these iconic islands —and one of their most iconic groups of animals, the birds known as Darwin’s finches— as the arena for tackling an appropriately Darwinian question: How do humans alter the trajectory of other species’ evolution?

This question is at the heart of Darwinian theory itself.  The very name that Darwin gave to his mechanism for evolutionary change reveals how difficult it is for humans to think about evolutionary change without becoming self-referential.  Natural selection is actually a passive process in which nobody is directly or consciously selecting anything.  The wing length or leaf shape or antennae placement that is “selected” is merely that which allows the animal or plant to face the challenges presented by its environment and have babies that can do the same.  The term “natural selection” reflects the analogy that Darwin made between what happens in nature, the product of mere survival, and what happens when humans interfere with nature and breed specific features into animals and plants through artificial selection.

In other words, humans have long been altering the trajectory of other species’ evolution.  But animal and plant breeding is only the most obvious and most intentional way that we do this.  As animals ourselves, with our own needs and interests, we have also been unintentionally changing the course of evolution since we came into existence.

How do we evaluate the evolutionary effects that we have on other organisms?  More to the point, must we evaluate them?  All animals and plants irrevocably shape the evolution of others in ways both large and small.  How many of these organisms waste time worrying whether these evolutionary impacts are good or bad?  It’s probably safe to say that Homo sapiens are the only ones.

In the case of Darwin’s finches on the Galápagos Islands, our authors begin with the premise that the human effect on evolution is a bad one.  They investigate the loss of diversity within a particular population of finches.  Darwin’s finches are distinctive for their specialized beaks, whether they eat insects or nectar or cacti.  Medium ground finches (Geospiza fortis), the focus of this study, eat seeds.

Four of the fourteen species of finches found on the Galápagos, an image from Darwin's On the the Origin of Species, published in 1859.

Following this particular species over the decades, researchers have observed that it appears to be diverging into two specialized “morphs,” two groups with different beak forms. Medium ground finches with larger beaks specialize on larger, harder seeds, and those with smaller beaks specialize on smaller, softer seeds.

But the population in Academy Bay on Santa Cruz Island looks different.  Academy Bay is one of the more populous human communities in the Galápagos and, as a result, human foods have become more and more available to the finches.  This wealth of new food has slowed down the evolutionary divergence-in-action, leading to the slow homogenization of beak sizes in the Academy Bay population.

As de León and his colleagues put it, human food is “eroding the diet-based disruptive selection that is thought to have previously maintained beak size modality in G. fortis.”  Simply put, elsewhere in the Galápagos, the natural food sources of these birds seem to be driving the evolution of these finches into two distinct groups.  But the presence of humans and their foods stifles this evolutionary process.

Why do we care about “eroding” the “disruptive selection” in the Galápagos—or anywhere, for that matter?  One critical reason is that this type of selection maintains diversity.  And diversity represents evolutionary potential.  In a world that changes all of the time in unpredictable ways, diversity is the source of adaptation to change.  Genetic diversity within populations is a natural resource, an evolutionary reserve; if climate change eliminates the food source that most individuals in a population rely upon, a few hardy survivors could still exploit some new and unanticipated food source.  But that potential only exists when there is diversity within a population.  It’s trite but true: diversity is the raw material of evolutionary adaptation.

The authors conclude that the case of the medium ground finch in Academy Bay is another example of “the importance of conserving the processes that generate and maintain biodiversity, rather than just the product of those processes.”  The products, of course, are the organisms themselves.  This approach to conservation has become increasingly common in recent years.  Its proponents argue that we miss the point of conservation when we champion the cause of individual species and ignore the processes of biological change that generate the all-important, more valuable prize of diversity itself.

As arguments for conservation go, protecting an evolutionary process probably does not tug the heartstrings of most nature lovers.  And as an intellectual argument, it’s important to note that evolution and evolutionary processes do not themselves have any intrinsic value.  When we argue for the conservation of an evolutionary process, we must argue for it as an investment in the future, an investment in the generation of biological unpredictability in all of its incipient evolutionary potential.

But it’s difficult to know precisely how an evolutionary process may be conserved, and it’s a question that the authors do not address in this paper.  In the case of Darwin’s finches, you might assume that the authors would advocate the restoration of the disruptive selection “eroded” by the availability of human foods.   But they could hardly argue for the elimination of the human influences on finches in Academy Bay.  After all, without humans, these biologists would have missed their chance to watch a new evolutionary story playing out.  In other words, while the human community in Academy Bay could be taken as a threat to the Galápagos, we can also appreciate how it increases the archipelago’s utility as a “natural laboratory.”

Even Darwin’s finches could find some utility in their entanglement with humans.  Without access to human foods, the medium ground finches of Academy Bay may have continued to diverge into two new species, each one specialized on its respective food source, thanks to its respective beak size.  The multiplication of species is certainly a form of diversification.  The irony, however, is that specialization does not necessarily lead to great adaptability in the future.  In this sense, then, losing the close linkage between a specific food source and a specific beak morphology could be a boon for the medium ground finch, a generalizing force that might allow them to exploit a variety of foods in the unpredictable future that they face.

Should these last arguments for the utility of human influence make your inner conservationist cringe, consider that humans have always influenced —and been influenced by— the evolutionary trajectories of other species.  It’s only recently that scientists have seen this form of evolutionary interaction as suitable for naturalistic investigation.  And what more appropriate place to investigate the place of humans in evolutionary processes than in the iconically Darwinian Galápagos Islands?

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.

On really striking out and (sometimes) striking el oro

Tuesday, February 24th, 2009

About luck. The notion has been irritating me for the past few days. I’ve always been interested in how chance operates in my own life. Like most people, I usually construct a nice satisfying retrospective narrative about my life. But chance has always played an unsettling starring role, throwing a wrench in the aesthetics of that erstwhile smooth story arc—you know, the one where I make wise conscious decisions and directly control the events of my own existence?

My sense of the importance of chance has only been heightened in my dissertation research, in observing its importance in the lives of pretty prominent scientists. This is not just the historian’s impartial eye, observing how life deals different hands to different players. This is the witness borne by those players themselves! Renowned biologists—known for their brilliance and not, typically, for their humility—have repeatedly credited chance with the paths of their careers. Paul Ehrlich. Dan Janzen. These guys have taken unusual and sometimes unpopular stances on ecological issues—in other words, they give the impression of deliberately charting their own courses. And yet, Janzen loves the words “serendipity” and “serendipitous,” and applies them liberally to the story of his own career.

Of course, when Janzen speaks of “serendipitously” stumbling upon an ant acacia while roving across Costa Rica in the early 1960s, he is not talking about pure chance. He is talking about the convergence of luck and preparation; the effect of a particular experience upon a mind primed with just the right kind of knowledge and previous experiences. The true luck is almost always in the timing of that critical experience.

Like Janzen, we’ve been doing some roving across the Costa Rican landscape, hoping for such a lucky convergence. We have no concrete information directing our mushroom search at the moment; only a knowledge of the general rainfall patterns for the season and a sense of where oak trees might be found.

Walking along a forest trail during the dry season might remind you of autumn in North America. Deciduous trees lose their leaves here just as they do in the temperate zone—it just happens to be during the “summer,” the drier and sunnier time of year. According to the Costa Rican bird Bible, Skutch and Stiles’  Birds of Costa Rica, it was the Spanish that declared the dry season summer, arriving with their memories of a hot and dry verano and cool and wet invierno.

If you’re lucky enough to have made it to an oak-dominated forest, however, you might still look up and see a truly regal canopy above your head. These oaks are closely related to the evergreen live oaks of the Southern U.S. And while “regal” might seem a cliché, under the circumstances, it’s spot-on. The oaks we have seen here are hundreds of years old, many feet in diameter, and verdantly populated with mosses, lichens, and bromeliads. There’s something so vital about the silhouette of an oak tree. The leaves burst so densely from the awkward joints of its branches. Its body looks haphazardly assembled and, at the same time, absolutely coherent. Coherence is a concept, but I would even say that an oak tree is cohesive, in a purely physical sense, as if it is gathering its deep green pigmentation along with moisture and light and a body of cool air, directly from the air around it. When each branch supports a dozen bromeliads, and their bright fuchsia and maroon and yellow-green leaves glowing translucently from above, this sense of pure organic gravity, of substance and sustenance, is intensified.

Rhapsodies over the beauty of oak trees, however, do not a successful collecting trip make! Oak trees are also mycorrhizal symbionts, living in intimate collusion with fungi, whose hair-like mycelia connect with their roots underground, sharing nutrients and minerals in an exchange that sustains both tree and fungus. Finding an oak means finding its fungal symbionts, which, if we’re lucky, have fruited above ground, producing those reproductive organs that my dear husband so desperately seeks: mushrooms.

This is where serendipity comes in. There are thousands of acres of forest reserve and national park in Costa Rica. Most of this is completely inaccessible, or else only moderately accessible, especially for people that need to collect mushrooms, photograph them immaculately, in situ and against a gray background with an herbarium collection number, take DNA samples (because this is, after all, part of a DNA barcoding project), and then dry them completely in a food dehydrator. So, via various points of entry, public, private, and otherwise (meaning, we’re not quite sure who owns the land or the road by which we reach it), we try to get at this inaccessible core of forest.

For our purposes then, these roads and trails are essentially random cuts in the forest. We can steer ourselves toward higher altitudes, where oaks and other mycorrhizal tree species are more common, or toward the rainiest provinces, but the decisions made decades ago to build a trail along this ridgeline or blast a switchback for the road into that hillside, may or may not take us precisely where the mushrooms just happen to be fruiting today. As much we have prepared for this trip, there will always be the discomfiting suspicion that somewhere—maybe even just a measly kilometer to the east or the south—the mother lode of mushrooms is elbowing its way up through soil and detritus, where we will never find it.

Anyway, that’s how it feels today. Fieldwork, especially when the task is opportunistic collecting in an attempt to document fungal diversity in the region, can sometimes boil down completely to luck. And luck is not with us in other ways, as well. We are three days into this collecting trip and have yet to see the collection and export permits for the mushrooms we are supposed to be collecting. Bryn started the process of applying for these permits more than two months ago, at the moment he knew that his teaching trip would be extended into a collecting trip. Unfortunately however, the term “process” implies that there is a straightforward method for obtaining such permisos. In reality, successfully scoring a permit turns mostly upon finding a reliable contact on the ground, a contact who also has a functional working relationship with the relevant bureaucratic body. It’s not entirely clear what went wrong, but it seems to be a little bit of a failure in both aspects (maybe more heavily the former than the later, I might add).

In any case, we have not yet been able to collect in Parque Nacional Tapantí-Macizo de la Muerte, as we do not have the relevant permits. So, we are reduced to making even more random forays into the landscape, in hopes of finding mushrooms on land where park rangers are not likely to be breathing down our necks. This morning, over weak coffee (Costa Rica is a coffee-producing nation that reserves its most drinkable beans for export and tends to disappoint the palate with weak and bitter brews in person.), Bryn identified a small “protection zone” called Cuenca Rio Tuis, perhaps a couple of hours drive from our hotel in the small village of Orosi. It seemed a little far away, but also unlikely to be heavily monitored, and according to our topographical map, it reaches a peak elevation of 1963 meters and may even have oaks.

It was a lovely drive, on a fantastically sunny day, over mountainside roads that rapidly drop and fall while they and around Lake Cachí. Everywhere that we drove, a brief wave or a “Buenas!” out the window of our car transformed that standard hard-edged impersonal glance you turn toward a strange car into smiles—people are incredibly nice to strange gringos blowing unexpectedly through their tiny little hamlets.

coffee plantation

At first, at the higher elevations, we drove through coffee plantations. Coffee is Costa Rica’s grano de oro, “grain of gold,” which brought prosperity to this nation named “rich coast.” Workers alongside the road were spraying the beans with a pesticide. These workers are, reportedly, mostly Nicaraguans, since Costa Ricans are no longer willing to lower themselves to earning something like $1/bushel for picking el grano de oro. The shade-grown varieties actually appear to receive a good deal of sunlight, especially since many of the scattered trees planted to give them shade are deciduous, with only bare branches remaining, which cast crooked shadows (if not actual shade) over the coffee. Other plots are stocked with imported eucalyptus, trees that at least retain their leaves during the dry season.

dscn0249Halfway through the drive we made delicious tomate, aguacate, y queso fresco sandwiches for ourselves at the roadside. At lower elevations we began to see the sugarcane fields, where men with machetes hacked away at their stalks. Near the end of the day we passed a plant where trucks full of sugarcane stalks pulled in for processing. The men trailed down the roads slowly in the wake of the trucks, looking exhausted, machetes still in hand, while a smoggy burnt-caramel smoke filled the Orosi valley.sugarcane truck

Finally we reached our little forest reserve. Or…..we’re pretty sure that we did. After all, most of the roads are not signed and the GPS is often little help in finding our position on what seems to be a pretty imperfect map (it’s missing an entire huge lake?!). Driving into the reserve on the potholed dirt road through increasingly tiny villages (where people seemed even friendlier, in inverse proportion to the size of their towns), we started to get excited about the wooded hills that we could see ahead. When a road winds around so much, you really just have to keep faith that eventually you will reach that mirage of forest on the horizon.

abandoned houseWe passed a couple of abandoned house, one with half-collapsed porticoes and arches and windows that still contained shards of glass. We’ve tried to decipher graffiti from the side of the building, but it’s hard to read from my passing photograph: Aqui es solamente / No se aqui que / porque aqui.” Bryn says I’m wasting my time trying to read this nonsense, like a bathroom wall in the basement of some bar in Toronto. It’s something like: “Here is only / I don’t know here what / why here.” Indeed.

Anyway, eventually, we had to turn on the 4-wheel drive to cross a little river with steep embankments on either side and a little catarata (waterfall) in the center. But we never got much higher, and we never got much closer to that elusive deep core of forest. We drove as far as we could on the road, to a place where the mud was ridged so deeply in a sharp turn that we couldn’t imagine the car handling both challenges simultaneously. So we did a little bit on foot. And it was disappointing mycologically.

But for me, with the mud on my boots, and the humidity that layered my face in sweat the moment I started to climb the steep trail along the hillside, and my first glimpse of something as common as a bird-of-paradise flower—all of these started to melt that icy nucleus of Torontonian slush and snow at my center. Running my hand along a mossy boulder, I had a tempting moment of synesthesia, and I was certain that I could taste the deep green in the blade of a bromeliad just above my head. So, although we struck out mycological today, I feel finally that I have really arrived in Costa Rica, and I’m excited to try our luck again tomorrow.sunset drive back to Orosi

Darwin’s dirty little secret

Thursday, February 12th, 2009

An otherwise inspired tribute to natural history buries the fossils of Darwin’s theological ancestry and misses its chance to challenge Intelligent Design.

10-pound bill

When “Darwin: The Evolution Revolution” first opened at New York’s American Museum of Natural History in 2005, creationist critics were among its first visitors.  Reviews on Intelligent Design blogs found the show “biased” and “dogmatic,” and, even worse, burning with a “Darwinian fundamentalist” zeal.

What gives?  Thousands of visitors have already enjoyed this exhibit in New York, Chicago, Boston, and Toronto.  It’s currently on display at the Natural History Museum in London, as Britain gears up for the 200th anniversary celebration of Darwin’s birthday on the 12th of February.  Will hordes of visitors look back on the exhibit and remember what a hard time those doctrinaire Darwinians gave God?

I doubt it.  In fact, Intelligent Design will be the last thing on visitors’ minds as they reflect back on “Darwin.”  And frankly, I think that’s a shame.  If an exhibit about Darwin’s legacy is not the perfect place for biologists to face the Intelligent Design movement, then where will they do so?

This exhibit promises to unpack the wild and woolly head of one Charles Robert Darwin and, to a large extent, it delivers.  We meet Darwin in his privileged early-19th-century childhood, where he picked up the compulsive habit that would haunt him his entire life: Collecting the flotsam and jetsam of the English countryside when he should have been studying, making him a “scapegrace” according to his physician father.   But Darwin turned his disgrace into a virtue, learning to “look closely” at all of nature, mastering the ultimate “simple tools” of an authentic biologist, his own eyes.

These two themes of the exhibit, “Looking Closely” and “Simple Tools,” are put to elegant use, connecting visitors with the lived experiences of Darwin.  We peer through Darwin’s magnifying glass and stand in a replica of the study where he wrote the great tomes of his adulthood.  The exhibit shares iconic Darwinian stories, like his mad questing for beetles, which drove him once to “collect” a beetle in his mouth, for want of a free hand.  The beetle spewed an acrid repellant, an effective way to avoid being eaten, whether by a hungry bird or a desperate naturalist.  Paired with historical artifacts—in this case, beetles collected by Darwin himself—these stories bring him to life and reveal an intimate contact with nature, cultivated from childhood onward.

When I caught the exhibit last year at the Royal Ontario Museum (ROM) in Toronto, I had a chance to speak with its local curator, entomologist Chris Darling, who shares more than just a passion for insects with Darwin.  As a child, he too spent a lot of time outdoors, laying the experiential foundation for his life as a biologist.  According to Dr. Darling, an urgent concern addressed by the exhibit is “the demise of the naturalist,” the disappearance of biologists who concentrate as intensely as Darwin (who spent nearly a decade becoming the world’s expert on barnacles) while maintaining a broad base of knowledge and experience, observing and cross-referencing information from diverse sources.

And the exhibit certainly samples from many of these diverse sources, bringing home the enormity of Darwin’s accomplishment. That is, the synthesis of such a swarm of biological and textual information that most people would simply give up and go home.  In this exhibit you may catch African spurred tortoises mating, touch a replica of the giant extinct armadillo fossil that Darwin found in South America, and witness moments of startling insight, recorded in Darwin’s own hand, in an original research notebook.

Visitors to the ROM on opening day were dazzled by the dual quality of breadth and depth on display.  “How could you not be impressed by a man who acquired so much scientific knowledge during his life?” commented a young woman, an American tourist who proudly informed me of her Christian faith.  Another visitor, an aging Torontonian schoolteacher, struck by Darwin’s wealthy background, saw the exhibit as a demonstration of what can be accomplished by specialist scientists when they have sufficient resources to delve deeply into a topic. Natural history museums worldwide should applaud this exhibit for the case it makes in support of “Darwinian” science: Visitors see the value of collection and careful observation, and the ever-expanding catalogue of life that is the backbone of modern biology.

By contrast, the molecular tools that many of today’s evolutionary biologists use in their daily work merit no more than a cameo.  For this omission we can hardly blame the creators of the exhibit.  After all, “Darwin” is already packed with artifacts and ideas, and its creation must have been an excruciating surgery, where the organs excised seemed just as vital and vibrant as what remained.  Pride of place is rightly given to the specimens, tools, and documents of a Victorian naturalist.  Yet, despite the success of this central theme, the curators’ scalpels went astray when they carved away the history of Darwin’s theological education. What seemed like a vestigial organ to them—a useless bit left over from our ancient ancestors, like your appendix or coccyx—was more like Darwin’s carotid artery, the wellspring of some of his most important observations.

At the risk of sounding a lot like those complaining creationists, I protest: there wasn’t enough Intelligent Design in the exhibit!  And I’m not talking about bringing in the masterminds behind the Big Valley Creation Science Museum in Alberta to give “Darwin” a facelift.  Instead, I’m talking about the very heart of Darwin’s scientific training at Cambridge, natural theology, which took his love of “looking closely” at organisms and turned it into a scientific skill.

Instead, Darwin’s deepest scientific insights seem to arise de novo.  In its effort to depict Darwin as a revolutionary, the exhibit text implies that he was the first person to critically examine similarities between different species.  In “The World Before Darwin,” we are told that all species were considered “unconnected and unrelated.” The text asks, “Why didn’t more people grasp that similarities in skeletal structures—so clearly visible—were a clue that species are related?”

Why?  Because the best comparative anatomists of the day, Darwin’s own mentors and colleagues, saw the shared skeletal structures of different species, known as homologies, as evidence of God’s design, his master plan for the living world.  Darwin was able to challenge this view only because he had assimilated its lessons so fully.

When the young Darwin looked closely at the world, he saw those homologies just as clearly as his colleagues did, as evidence of design.  But like other good observers of his day, Darwin began to see the flaws in this approach.  If God were so intelligent, why would he give a bat’s wing, a human’s hand, and a whale’s flipper the same skeletal structure?  Didn’t he have the basic engineering chops to devise specialized designs, better suited to the job that each type of limb does?

As Darwin learned more about anatomy, collecting animals both extinct and extant, he came to see homology as evidence for evolution.  And he had no trouble convincing his colleagues, also students of natural theology, of the same. Today, homology still stands as one of the most vivid demonstrations of our evolutionary heritage.  Our human hands share a skeletal structure with a bat’s wings and a whale’s flipper because we all share an ancestor in the distant past.

Because of the visual power of homology, the exhibit relies on it as evidence for evolution more than once, making the absence of natural theology that much more regrettable.  In leaving out this part of Darwin’s story, the creators didn’t ditch a pesky detail only a historian could love.  They missed an opportunity to explain the early prehistory of Intelligent Design, which is basically, “Been there, done that.”

How can we explain this oversight?  It may be, as ROM CEO William Thorsell commented at a media preview, that “Darwin is still too hot to handle.”  After all, “even in Canada,” it was impossible to find corporate sponsorship to support the exhibit until nearly a week after its opening.  In seeing the controversial content on their hands, perhaps the exhibit’s creators decided that Darwin’s training in 19th-century “Intelligent Design” was better left unmentioned.

In portraying his religious sentiments as nearly nonexistent, they sanitized the exhibit of Darwin’s dirty little secret, his theological education. We learn that Darwin, who was trained as a clergyman at Cambridge, brought a swanky engraved German Bible on his five-year voyage around the world, along with his more practical pistol and “peacemaker” club.  Anyone who has studied Darwin’s letters could tell you that he was, in his own words, “a very poor German scholar,” an insight that confirms what is implied by this display case: the Bible was just an accoutrement of travel, perhaps more effective as a weapon than as a source of inspiration.

And how do today’s biologists deal with God?  In answer, a human-sized video screen simulates conversation with a number of prestigious biologists, a valiant attempt to create some kind of dialogue. But the conversation is one-sided. And guess who’s talking?  God-fearing head of the Human Genome Project, Francis Collins (not an evolutionary biologist), blandly assures us that faith and science are “complementary.” A nattily dressed engineering student described the video as “interesting” but hardly enlightening.  “It still leaves a lot of questions for me.  I don’t think I understand anything more about the controversy.”

Nearby, a biology textbook is displayed, branded with the kind of disclaimer sticker disseminated by the Intelligent Design movement, claiming that evolution is “only a theory.”  Another video tries to answer this challenge: scientists stand again in a featureless room, talking at the visitor, explaining that a “theory” in science is not merely a guess, but a critical “framework” within which facts are understood.

But these videos are all just talk.  Visitors have been told time and again, before they even arrived at the “Darwin” exhibit, that science is dynamic, self-correcting, allowing its most treasured principles to be toppled in the face of solid evidence.

Ironically, the story of natural theology, so carefully avoided in this exhibit, is a real-life account of just how such foundational concepts in science may be challenged. Though it is neither biased nor fundamentalist, as creationists claim, in overlooking the “Intelligent Design” in Darwin’s own intellectual history, this exhibit misses an authentic demonstration of the ideals it professes.  Worse, it sidesteps a meaningful discussion of Intelligent Design and why—as science—it just doesn’t cut it.