Looking Closer at Look at Your Fish

“In science, I concluded, even in fields as apparently apolitical as ichthyology and glaciology, the story always involves more than a fish in a tin pan or lines etched on bedrock. Culture, history, and beliefs about humans determine, now as in the nineteenth century, who exactly is invited into the science laboratory to “look and look again” at the fish in the pan, and who exactly has the leisure and means to take a trip to Maine.”— Marion K. McInnes, “Looking for Louis Agassiz: A Story of Rocks and Race in Maine” 

Less than a week after I published a blog post that referenced Louis Agassiz and the Look-at-Your-Fish-school-of-natural-history-instruction, I stumbled upon an essay that upended my perception of Agassiz, glaciers, and the apocryphal fish. “Looking for Louis Agassiz: A Story of Rocks and Race in Maine” flashed on my radar via my google scholar alert for Acadia National Park and Dr. Marion McInnes pulled me down a history of science rabbit hole to face my own field site and writing in an unforgiving mirror. 

McInnes weaves together the geologic history of Mount Desert Island, Maine, Agassiz’s well-founded theories on glaciers, and his illegitimate theories on race in an astounding piece that’s part archival detective story, part cultural criticism. This essay is engaging and thought-provoking and scathing. I did not escape unscathed. Because, here’s the thing: I elided Agassiz’s racism when I quoted Look at Your Fish. I knew better — I read Chrisoph Irmscher’s 2013 biography Louis Agassiz: Creator of American Science and half-remembered Agassiz’s spurious writing on superior and inferior races even as I was typing up pithy takes on his pedagogical style. 

Both McInnes’ essay and Irmscher’s Agassiz biography cover the breadth of Agassiz’s career as a scientist and teacher. In the mid-19th century, Agassiz leveraged his position as a public intellectual to expound on race: his writing and lectures added scientific credence to the idea of the white superiority. He was an abolitionist and a champion of glaciers over the biblical Noah’s flood as a geologic force. He also rejected Darwin and believed in a theory of multiple creations, which included separate creations for different human races, the “newest” and best model being white Europeans like himself. My personal brand is loving 19th century naturalists, and my historical ecology research makes it clear that all my favs are problematic. This essay reinforces the important point that glossing over these problems, especially if they were cultural norms, is itself problematic. 

McInnes’ essay centers on her quest to find the Agassiz Outcrop, a site that, at the outset, she believes is a National Historic Landmark in Maine celebrating an outcrop of 510 million-year-old Ellsworth Schist bedrock bearing glacial striations and Agassiz’s name. Except she discovers that the Agassiz Outcrop is unmarked, half-hidden beside a parking lot, and its status has actually been inflated by a mistake on Maine.gov — it’s on the National Register of Historic Places, added in 2003, but it is not a capital ‘L’ Landmark. Ellsworth is on the mainland side of the bridge to Mount Desert Island; it’s where I do my grocery shopping on my way to my field housing each spring and boasts the Home Depot where I’ve spent thousands of dollars of grant money on corner gutter pieces, zip ties, cloth weed barrier, and various other field ecology supplies.

As I read McInnes’ essay, I could picture most of the geological formations she references — the pink granite, the glacial erratics — but I had never heard of the Agassiz Outcrop. Then, I saw her photo and I immediately recognized the parking lot.

I’m a pretty curious person with a stubborn streak in research projects, but I’m not sure I would have followed the threads that McInnes plucks from here; I think I might have let the project die in that parking lot of underwhelming landmark status and disappointment. I am genuinely amazed by what McInnes has crafted from the ashes* of the Agassiz Outcrop anecdote, and her dedication to unwinding the story of Agassiz, this outcrop, and the cultural moments they connect. As she writes in her introduction, “when I started this project I thought I was taking a trip back to the Palaeozoic and pre-Cambrian Eras, but in fact I landed squarely in the nineteenth century.” 

Among my favorite moments in this essay is when McInnes reads Agassiz’s ‘Glacial Phenoma of Maine’ from a bound copy of the year-end edition of Atlantic Monthly in her college library: “When I took down volume XIX to look for Agassiz’s articles on Maine, the leather spine tore along the seam; red dust coated my fingers and stained my clothes. All the better: this was the volume published in 1867, here in my hands, and not on a sterile computer screen.” A more recent paper on Maine glaciology looms large too: Smith and Borns’ “Louis Agassiz, the Great Deluge, and Early Maine Geology” published in Northeastern Naturalist nineteen years ago. Smith and Borns turn out to be the catalyst behind the Agassiz Outcrop’s listing on the National Register of Historic Places; it was their recommendation that landed the site this honor. But McInnes is more interested in what Smith and Borns’ left out of their writing on Agassiz: race. 

“In their article for Northeastern Naturalist in 2000, Smith and Borns sidestep the issue of Agassiz’s racism; they simply do not refer to his views on race at all. One might argue that they wrote this piece, after all, for an audience interested in geology, not social history…Yet this reasoning does not suffice. In the last section of their article, Smith and Borns consider Agassiz’s legacy outside of his contributions to glacial theory; they highlight his contributions to science education, his skill as a mentor of future brilliant scientists, and his support of women…I can understand their quandary as writers, and I continue to appreciate the research Smith and Borns have done on nineteenth-century geologists, including Agassiz, who studied bedrock in Maine. But if Agassiz’s enlightened views of women are relevant to the case they make for his being ‘one of the world’s preeminent natural historians,’ then so are his views on race.” 

Here, McInnes cuts through a thousand thorny arguments with incredible clarity. Why did I feel so guilty reading this after publishing a blog post that conveniently forgot to mention Agassiz’s racism? I think McInnes nails this sin of omission. In her writing on stripping memorials of problematic namesakes she plucks a perfect metaphor from the google map view of the road that passes by the Agassiz Outcrop: a ‘FILL WANTED’ sign. “This alternative, it seems to me, calls for research and interpretive work rather than erasure of the past. We want and need the full story of science history: we need to fill in what has been left out of geology textbook chapters on Agassiz’s Ice Age Theory; and “FILL” could usefully be added to the signage in the galleries of what once was the Agassiz Museum of Comparative Zoology.” 

I cannot recommend this essay enough. When I teach Field Natural History, I will assign it in tandem with Look At Your Fish; the two pieces are now inseparable in my mind.

It is amazing how this improbable connection came together: an essay written by a Professor Emerita of English at DePauw University, published in the latest issue of Mosaic, an interdisciplinary critical journal that I’d never heard of before. This is, by all accounts, a paper I should never have read. But, the practice of reading a paper a day can be expansive and magical; it can allow for opportunities to read broadly and cast a wide net, or an interdisciplinary Acadia-sized-net. For these reasons, I’m just sort of charmed that my off-again on-again dedication to #365papers became a conduit for the universe to reach out and smack me for letting Agassiz’s racism slide unchecked in the year of our goddess 2019. I will do better. 

*terrible wordplay here — Ellsworth Schist is not igneous rock. 

Reference:

McInnes, Marion K. 2019. Looking for Louis Agassiz: A Story of Rocks and Race in Maine. Mosaic: a Journal for the Interdisciplinary Study of Literature. 52(2): 35-56. 

Pikas Meet Cute: Two Subspecies, One National Park

The National Park Service is wrapping up celebrations on its 102nd anniversary this August. I’m unabashedly biased towards park science: my dissertation and my postdoc research are both Acadia-based, while cleaning out old papers last week I actually paused for a moment before recycling a torn up, coffee-stained copy of a National Park research permit from 2013. (Don't worry, the original pdf is safely stored on an external hard drive.)

I’d report on the hybridization of pikas in Rocky Mountain National Park even without the excuse of a belated happy birthday to the National Park Service, but clearly covering research on pikas and #poopscience is the perfect way to honor the stewards of our public lands. There are charismatic megafauna (mini-fauna?) and there are charismatic landscapes, and the scientists who study pikas in the western National Parks enviably have cornered the market on both. Dr. Jessica Castillo Vardaro just published new research on the population genetics of American pikas in PLoS ONE last month. In “Identification of a contact zone and hybridization for two subspecies of the American pika (Ochotona princeps) within a single protected area” Castillo Vardaro and coauthors analyze the DNA in pika poop to pinpoint where the northern and southern Rocky Mountain lineages of these rabbit relatives meet. Their pika #poopscience spanned samples from Grand Teton National Park, Great Sand Dunes National Park, and Rocky Mountain National Park.

Before Castillo Vardaro’s work, there was some evidence that the northern and southern Rocky Mountain pika subspecies had a historic contact zone somewhere near-ish Rocky Mountain National Park. However, Castillo Vardaro wasn’t looking for a contact zone or hybrid pikas when she began working on the Pikas in Peril (PIP) project — a team of National Park Service staff and academic researchers. Pikas are a bit of poster child for climate change vulnerability — “a climate indicator species” — because they cannot tolerate prolonged exposure to high temperatures. Castillo Vardaro’s initial genetic analyses of pika populations in western National Parks focused on signals of isolation by distance (IBD). She explains, “the further individuals are apart geographically, the less related they are genetically. Since pikas typically establish territories close to where they were born and mate with their neighbors, I expected to see strong signals of IBD. I did in all of my study sites except Rocky Mountain National Park (ROMO).” Comparisons of the pika samples and their sequences to Genbank showed that there were two genetic lineages represented in ROMO — Northern and Southern. Then, at a pika meeting (could there be a cuter meeting?) Castillo Vardaro met Preston Somers, a researcher who studied pika dialect in the Rockies in the 1970's. She notes, “His work suggested there might be a contact zone, but we were the first to actually show it and evidence of contemporary gene flow. So, we weren't initially interested in studying ROMO as a potential contact zone, but we are now.” The analyses in this research are steeped in #poopscience, or what the paper refers to as “fecal samples…through a combination of random, targeted, and opportunistic sampling.” I asked Castillo Vardaro about the trade offs of #poopscience versus tissue samples. As a plant ecologist, my Methods have never included gems like, “We avoided collecting old fecal pellets by preferentially collecting pellets with green plant material inside to avoid degraded DNA” — but I was curious to hear more. Castillo Vardaro expounded,

Fecal DNA is essentially the mucus and cells lining the digestive tract that then coat the fecal pellet as it passes through. There are very few cells compared to tissue (organ tissue or ear clips), there are other things present that can inhibit the PCR process like plant secondary compounds, and the feces has been sitting around outside for an unknown amount of time so the DNA can degrade. Each sample has to be genotyped multiple times to overcome the errors resulting from low quality/quantity DNA. My genotyping success rate was 50% - 75%, after removing samples that failed, contaminated samples, and multiple samples collected from the same individual unknowingly. That's a lot of work in the lab.

But, the #poopscience lab work pays off if you need lots of samples across a broad geographic area:

In contrast, I just got back from a week in Montana where I was helping my coauthor Chris Ray trap pikas at a site she has been monitoring for 30 years. In four days of effort (two trap days, but it takes a day to set up traps and a day to check traps/process pikas) we trapped 5 pikas. One person can collect 10-25 quality fecal samples in a day, plus anyone can collect fecal samples for genetic analyses after about 10 minutes of training. So while I would have preferred to have worked with tissue, there is no way to sample the number of individual pikas necessary for 10 high resolution genetic analyses if you had to trap every animal.

The collaborative nature of Castillo Vardaro’s research and the Pikas in Peril reminded me of an earlier blog post I wrote about the Biological Conservation paper “The importance of non-academic coauthors in bridging the conservation genetics gap.”  I noticed that Castillo Vardaro’s PLoS coauthors were all academics, but she pointed out that her coauthor and grad mentor, Clint Epps, designed the PIP project alongside National Park Service personnel and other academic researchers. “The questions, goals, and desired products were explicit from the beginning. These included National Park Service reports, summaries, briefs (publications on the web and available at the parks themselves), spatial data, and research that could be utilized in each of the parks.”

While Castillo Vardaro was doing field work, she worked with National Park Service and US Fish and Wildlife Service biologists, interns, and volunteers. She noted, “we worked with interpretive staff to prepare the park specific resource briefs. We (myself, Clint Epps, and Doni Schwalm) also wrote a note on the potential effects of a proposed quarry site in Grand Teton National Park on the pika populations there, which was provided to resource managers there.” Basically, this work (one of Castillo Vardaro’s dissertation chapters) is the exception that proves the rule to the non-academic coauthors paper: here, the coauthor list belies the strong partnerships with non-academic scientists and managers, and if you didn’t know about Pikas in Peril, you might think wow, these academics really know how to put together explicit management implications single-handedly! 

Finally, in Castillo Vardaro’s research I saw a mirror of my own dissertation work. I had no pikas or fecal DNA, but we both finished our dissertation field work in National Parks before the 2016 election. Her work could inform whether pikas are listed as endangered or threatened under the Endangered Species Act; my research supported a climate change vulnerability assessment; and after our halcyon days as PhD students under the Obama administration, we are now watching an administration and Secretary of the Interior generally disregard the National Park Service expertise on these issues.

I told Castillo Vardaro that I feel an extra sense of urgency in publishing my Acadia papers now — especially in open access venues. I wondered if this was a personal quirk or if she felt a similar sense of responsibility for her field sites and study species. She agreed that highlighting the work that we are doing on public and federally managed lands is even more important in the current political climate. “One of the main reasons I chose to publish in PLOS ONE was because I wanted the manuscript to be accessible (open access).” She also noted that, “the PIP project was funded as part of the NPS Climate Change Response Program. I do worry about continued funding for similar projects and initiatives under Zinke and the Trump administration. Pikas tend to live in places that aren't as directly impacted by development as other ecosystems (it would be difficult to put a subdivision on the steep, rocky, side of a mountain), but the policies and proposed changes to the Endangered Species Act under the current administration to make it easier for development and resource extraction on public lands could definitely impact pikas.” 

The flipside of non-academic coauthors bridging a conservation gap is this: when the federal government is hostile towards non-extractive natural resource management, the academic coauthors in these partnerships will continue to publish our findings, piling up the evidence to support our field sites and our study species. For those of us in academia who completed National Park fieldwork in what seems like another era, getting the writing done can seem both daunting and futile. It's not. Traditionally, the first wedding anniversary is the “paper” anniversary, but for the National Park Service’s 102nd I think papers are still an appropriate — and important — gift. 

References:

Castillo Vardaro JA, Epps CW, Frable BW, Ray C (2018) Identification of a contact zone and hybridization for two subspecies of the American pika (Ochotona princeps) within a single protected area. PLoS ONE 13(7): e0199032.

The Rollercoaster of Exploding Pollen

When I think about reading peer-reviewed natural history papers — including contemporary articles in a ‘Natural History Miscellany Note’ or ‘The Scientific Naturalist’ section — I imagine them mostly as a classic throwback: just a scientist, a hand lens, and a notebook. I generally do not think about employing $50,000 of high-speed video recording equipment to test dueling hypotheses about pollination modes from the 1860s. I’m clearly missing out. 

The American Naturalist recently published a mash-up of 19th century natural history observations and 21st century tech: in “Dispensing Pollen Via Catapult: Explosive Pollen Release in Mountain Laurel (Kalmia latifolia)” Dr. Callin Switzer and coauthors present speed records, specialized weaponry vocabulary, and plot twists. 

The Speed Records: Mountain laurel is well known for its explosive pollination — a great botanical cocktail party conversation starter*, but an adaptive function that has remained a mystery since the 19thcentury. Back in 2005 fans of understory plants of the temperate deciduous forest and speed records** were wowed by bunchberry — researchers from Williams College clocked this explosive pollinator launching pollen grains at 3.1 meters/second, and accelerating pollen at 24,000 meters/second2.Switzer’s research at the most basic level sought to record the speed and acceleration of mountain laurel’s explosive pollen. The mechanisms behind the explosion were well documented by the 1990s (pollen on the mountain laurel anthers are tucked into “pockets” in the petals and held under tension by curved filaments — when the anther is released from the pocket, the pollen is launched into the air), but the speed was still unrecorded. Switzer explains, “The paper was inspired by walking around the Arnold Arboretum with several of the faculty there. Robin Hopkins (my PhD advisor) and Ned Friedman both knew that I had done some high-speed video projects in the past, and they suggested that I should take a look at the mountain laurels. I first had the high-speed videography background, and then Robin pointed me to the 19th century literature.” From the high-speed videos, Switzerfound that mountain laurels launched pollen at 3.5 meters/second for an average maximum speed and achieved average maximum acceleration at 4,100 meters/second2. Mountain laurels thus have “one of the fastest-moving floral parts recorded”! But why? In 1867 The American Naturalist published competing hypotheses for the adaptive function of explosive pollination in mountain laurels. Was the pollen aimed at the stigma for incredibly efficient self-pollination? Or is the pollen catapulted on to visiting bees for cross-fertilization? These 19th century natural history observations sat at the heart of Switzer’s interest in quantifying the speed of mountain laurels — a chance to unravel this species’ mythology of adaptive explanations. “I think of natural history as a part of biology that starts with curiosity about the natural world.” Switzer reflects. “Naturalists tend to get ideas for projects simply by going out into the field with a hand lens and a notebook -- with all the new technology available, however, naturalists can do a lot more interesting and quantitative studies.”

Before revealing the speed-pollen’s adaptive function, I just need to acknowledge the weird side effect of reading about explosive pollen — I learned a ton about the physics and vocabulary of medieval weapons…

Specialized Weaponry Vocabulary: The next time you are struggling to articulate the difference between a regular catapult and a medieval trebuchet, just think about the difference between a mountain laurel and a bunchberry. While both flowers have filaments under tension and fling pollen from the tips of their anthers, on bunchberry anthers there is a hinge connecting the anther to the filament tip. The bunchberry trebuchet is a specialized catapult: the payload is attached to the throwing arm by a hinge. Mountain laurels may be standard issue catapults — without the hinge that propels bunchberry pollen with incredible acceleration — but mountain laurel pollen grains are structurally designed to be their own weapon. The mountain laurel’s pollen grains “form tetrads connected with viscin threads…causing each anther to release several stringy aggregations of pollen when it is triggered.” Switzer hypothesizes that these stringy aggregations may act as a bola— hitting a target/pollinator and then wrapping around to attach itself tightly. Both the bunchberry and mountain laurel papers weaponize their flowers, making explosive pollination seem explicitly conflict-driven. I asked Switzer, “Are plants at war with their pollinators?” He responded, “plants and pollinators are in evolutionary conflict -- they have different "goals", and both are constantly evolving to suit their own goals.  If you'll excuse the anthropomorphizing, plants "want" bees to keep pollen on their bodies and transfer it among flowers, but bees "want" to collect the maximal amount of resources, without wasting energy carrying pollen among flowers.” When we look closely at the world around us, the metaphors of natural harmony and balance blur and fade: petals are architects of secret triggers, flowers a minefield of exploding pollen. 

The Plot Twists: Switzer filmed 69 mountain laurel pollen explosions outdoors at the Arnold Arboretum to capture the insect visitors and causes of catapulting pollen. Bees — mostly bumble bees — triggered the anther catapults, while appearing to search for nectar. During this fieldwork, and in the playbacks of the high-speed videos, Switzer watched pollen fly past the bees. It seemed like the catapults were missing their target. Maybe this was an elaborate, Rube Goldberg-esque set up to have a bee trigger a catapult to self-fertilize a flower via an extremely fast but weirdly complicated mechanism?A second set of high-speed videos, recorded in the lab, allowed Switzer to calculate pollen trajectories in 3-D space. In these videos, the flower is set in profile to the camera and half the petals have been removed to give a clear view of the flower parts: stigma, style, anther pocket and filament. The catapult is manually triggered by a needle. When the pollen trajectories are traced and modeled into 3-D space, it’s clear that most of the time the catapulted pollen crosses the central axis of the flower at just about bee-height. Switzer admits, “I was very surprised when I made observations with only my eyes, and I saw pollen flying past the bees. I came up with all kinds of interesting explanations in my head, until I collected the high-speed videos and saw what was really happening.” In the Discussion of the pollen catapult paper, there is a refreshing transparency about this plot-twist moment: “Only with detailed experimentation and observations were we able to better understand the adaptive significance of explosive pollination—we realized that field-based observations did not allow us to see how much pollen actually hit the bee (because the bee’s body often blocked the view).”

The story of the research — stretching back to those 19th century naturalists and the mythology of adaptive explanations — is so clear here. We thought we saw something. We tested it from another angle and saw something else. 

As Switzer explains, “This was indeed a gut-check moment, and it did help me have more empathy for 19th century naturalists as well as present day naturalists. Doing good science with good statistics is hard -- it can be so easy for scientists (myself included) to convince themselves of something that is not true.  For me, it's really helpful to get constructive feedback from others to help me find those 'blind spots.'”

Switzer’s ultimate contribution — beyond allowing mountain laurel to rest on its speed laurels, side by side with bunchberry in the Fast Plants Hall of Fame — is this effort to keep looking: to bring in two high speed cameras, half-dissected flowers in a lab setting, and 3-D modeling, and shed light on the unknowns with every tool in his 21st century natural history toolbox.

References:

Callin M. Switzer, Stacey A. Combes, and Robin Hopkins, "Dispensing Pollen via Catapult: Explosive Pollen Release in Mountain Laurel (Kalmia latifolia)," The American Naturalist 191, no. 6 (June 2018): 767-776. https://doi.org/10.1086/697220 

Edwards, J., Whitaker, D., Klionsky, S., & Laskowski, M. J. (2005). A record-breaking pollen catapult. Nature,435(7039), 164–164. http://doi.org/10.1038/435164a    

*Botanical cocktail party conversation starters are definitely a thing. Just read Amy Stewart’s The Drunken Botanist.

**There are many fans of understory plants of the temperate deciduous forest and speed records. Just think of all the trail-runners you know who are also ecologists and/or iNaturalist enthusiasts. We generally have two speeds: extremely slow (botanical observations) and extremely quick (peak bagging). We pack lots of snacks. We have favorite races based on the phenology of the date and the beta-diversity of natural communities along the course. We like to poke things.