This is a bit of a rehash from the social media platform whose name I will not utter here, but earlier this month I made my first TV appearance as an “expert” on Joshua trees, talking about the Joshua Tree Genome Project common garden experiments as a first step towards assisted gene flow to help the trees cope with climate change. It was a weird experience! The reporter emailed to arrange things and I agreed to an interview on Zoom, but I didn’t fully realize I was being recorded for broadcast until we were wrapping up. Mercifully, he selected the most coherent bits of what I told him and I didn’t make too many weird faces.Continue reading
I’m delighted to announce a new paper published today in the Biology Letters, coauthored with Colin Carlson at Georgetown University and a CSUN undergrad researcher, Gio Gomez. In it, we examine a big collection of floral visitation records and find a pattern that pollination biologists have talked about but never quite directly demonstrated: the symmetry of flowers seems to shape the diversity of animals that visit them, and potentially provide pollination services. Here’s a brief “lay summary” we wrote to accompany the article:
For centuries, botanists have understood that the symmetry of flowers — whether or not they are “zygomorphic”, with a single line of symmetry — shapes how they attract and interact with pollinators. We examined 53,609 records of animal visits to flowers in 159 communities around the world, and found that zygomorphic flowers are visited by fewer potential pollinator species. This may explain broad patterns in the diversity of flowering plants, in which zygomorphic flowers are associated with faster formation of new species. It also suggests that plant species with zygomorphic flowers may be at greater risk of extinction due to pollinator loss.
This is an exciting paper because it’s my first foray into pollination ecology proper, and because of its place in that broader field of research — and also because it’s the first paper I’ve published with a student coauthor since starting on faculty at CSUN. On top of all that, the project has been a really nice bridge between my interests (mutualism) and Colin’s (host-associate community ecology), and it’s kicked off a collaboration that has produced some even more exciting results, coming soon to a preprint server near you.
Local adaptation, in which populations of a species become better able to survive and thrive in their home environment than in conditions found elsewhere in the species’ range, is a widespread pattern that evolutionary biologists have long used to study the causes and consequences of natural selection. My newest paper, which is now online ahead of print in The American Naturalist, combines data across many studies of local adaptation to answer a persistent question about the history of life on Earth — has evolution been influenced more by selection arising from environmental conditions, or by interactions among living things?
If I’m really going to take my digital life off Facebook, I have to get serious about tending to a more distributed version of that site’s functions. Exhibit A is my Flickr account, which I’ve gotten lax with updating — I was almost a year behind with uploading images there! The holidays have been a good chance to catch up, though, and I’ve finished updating through a trip to Spain and France for fieldwork last June.
I was there to take samples of Medicago truncatula along the Spanish and French Mediterranean coasts — ridiculously pretty territory, even when a snafu with my car rental meant I had to do a fair bit of collecting by mass transit and rental bike. I flew into Madrid (with a layover in London), then to the Spanish coastal town of Málaga; then I spent most of a week in and around Narbonne, France, and finished with a day in Paris before flying home (again via London). It was my first time in both Spain and France, and my first time in Europe in more than a decade.Continue reading
I’m very excited to see this in virtual print — it’s a new model of coevolution between mutualists that takes into account signals between the partners as well as the benefits they provide each other (or don’t).
Yoder JB and P Tiffin. 2017. Sanctions, partner recognition, and variation in mutualism. American Naturalist doi: 10.1086/693472.
I’ll try to write about this in more depth at some point, but here’s the lay summary at the American Naturalist website:
Mutually beneficial relationships between species, or mutualisms, are ubiquitous in the living world, with examples ranging from flowering plants that rely on animal pollinators to fish that clean the teeth and scales of other fish. Mutualisms are often imperfect — one partner or the other varies in the quality of the help it provides. Evolutionary theory predicts that this should break up the relationship, but most mutualisms hold together in spite of partners that take the benefits of mutualism without properly paying them back.
This paradox may be explained by the fact that there’s more to mutualism than trading goods or services. This is a key result of mathematical evolutionary models published in the American Naturalist by Jeremy Yoder and Peter Tiffin, biologists at the University of British Columbia and the University of Minnesota. Yoder and Tiffin built a mathematical evolutionary model of mutualists that communicate before trading resources, and compared it to simpler models with only resource-trading or only communication. In the model with communication and resource-trading, host could “sanction” by cutting off resources to prevent poor quality partners from taking over, but evolution of the signals sent by partners and the hosts’ response to those signals maintained variation over time. Neither of the simpler models could do this. With only resource-trading, sanctions eliminated all poor-quality partners, and all variation; with only communication, poor-quality partners took over the mutualism.
I’m very excited to announce that I’ve accepted a faculty position with the Department of Biology at California State University Northridge, starting this coming fall.
CSUN is about as close as possible to the ideal place to do the kind of science and scholarship I want to do — a large, diverse public university with strong support for teaching and research, and great colleagues studying ecology, evolution, and every aspect of the living world. Campus is located within half an hour’s drive (well, maybe an hour with traffic) from sites where I studied Joshua trees as a graduate student, and it has good facilities and an excellent climate for growing my favorite legume, too. (I’d be remiss if I failed to mention, as well, that CSUN should be familiar to fellow fans of “Crazy Ex-Girlfriend” as the alma mater of one Joshua Felix Chan.)
To extend a metaphor I used in an essay about being a postdoc last year, I feel like I’ve finally been called up to the big leagues. I’ve already submitted my first pre-proposal for NSF research funding with CSUN affiliation, with collaborators from the Joshua Tree Genome Project, and I’m making plans to hit the ground running with that project and others when I officially arrive on campus later this summer.
I also have a lab website and Twitter feed set up, and I’m looking for graduate students to start in the fall. The deadline to apply to the CSUN Biology Master’s program is coming up fast — interested students can find out the details here and drop me a line.
We’re in challenging times for teaching science and doing basic research, but I firmly beleive that the challenges scientists and educators now face make our work all the more important. There’s a lot of exciting science to be done, and I can’t wait to start.
My very latest scientific publication is now online at the American Journal of Botany. It’s sort of an odd paper — something of a review, or an opinion piece, discussing how population genomic data can help us understand why mutualisms stay stable [PDF] in spite of the risk of “cheating” by partners, with a “worked example” with data from the Medicago HapMap Project. Here’s some key bits from the abstract:
Different hypothesized models of mutualism stability predict different forms of coevolutionary selection, and emerging high-throughput sequencing methods allow examination of the selective histories of mutualism genes and, thereby, the form of selection acting on those genes. … As an example of the possibilities offered by genomic data, I analyze genes with roles in the symbiosis of Medicago truncatula and nitrogen-fixing rhizobial bacteria, the first classic mutualism in which extensive genomic resources have been developed for both partners. Medicago truncatula symbiosis genes, as a group, differ from the rest of the genome, but they vary in the form of selection indicated by their diversity and differentiation — some show signs of selection expected from roles in sanctioning noncooperative symbionts, while others show evidence of balancing selection expected from coevolution with symbiont signaling factors.
The paper is my contribution to a Special Section on “The Ecology, Genetics, and Coevolution of Intimate Mutualisms”, which I co-edited with Jim Leebens-Mack. You can view the whole Special Section here, and download my paper here [PDF].
You have surely, by now, heard all about Hope Jahren’s terrific scientific memoir Lab Girl, including as one of my “bookshelf” recommendations for Chronicle Vitae. My full-length review of Lab Girl is now online at the LA Review of Books, and it is, as you might expect, very positive — Jahren writes beautifully about the process of scientific discovery and the daily miracles of the natural world. As a postdoc still scrabbling for purchase on the lower rungs of the tenure track, though, Lab Girl managed to simultaneously tweak my anxieties and give me hope:
The world is heating up, and it often seems that the intellectual luxuries afforded to scientists of the past — Darwin’s leisurely publication schedule, Haldane’s dalliances with radical politics — are gone. Lab Girl’s rendition of the daily institutional frustrations of research marks it as a different kind of scientific memoir — but also as a product of twenty-first century science. If you navigate among scientists’ blogs or scroll through their Twitter feeds, you’ll quickly find the same fears and vexations and injustices Jahren describes, intertwined with accounts of the work that excites scientists’ passions. … Jahren does not makes science look like an easy career choice, but it isn’t her job to do so — and if Lab Girl chronicles the real and substantial barriers to becoming a successful scientist, it also makes that life compelling: she shows the fruit that can still grow from the rocky soil of a research career.
There’s big news today at the Queer in STEM project site: we’re about to launch a new iteration of our online survey. Queer in STEM 2.0 is happening thanks to Joey Nelson, a PhD candidate in geosciences at Stanford, who approached us last fall about developing a new study to build on what we’ve learned from the first Queer in STEM survey. He had some great ideas for new questions to tackle:
Do LGBTQ-identified people remain in the closet in STEM workplaces mainly because they feel a lack of support, or because STEM workplace cultures discourage discussion of personal lives outside the lab? How do LGBTQ-identified colleagues, mentors, and role models affect their careers? Does being “out” in the workplace affect their research productivity?
Queer in STEM 2.0 aims to answer these questions with a new online survey designed for more specific hypothesis testing. We hope to hear again from participants in the original Queer in STEM survey, and to achieve an even bigger sample from LGBTQ-identified STEM professionals across the U.S. and Canada. Finally, in our biggest innovation from the original study, we will also ask STEM professionals who don’t identify as LGBTQ to answer many of the same questions we will ask LGBTQ-identified participants, to provide a powerful new tool for understanding the survey results: a control sample.
Joey’s taken the lead in developing a new, more focused questionnaire that adjusts the questions it presents based on initial responses — so, hopefully, it’ll be a smaller time commitment for participants. We’ve also had help and input from Daniel Cruz-Ramirez de Arellano, a chemist at the University of South Florida who’s already worked with Allison to analyze one-on-one interviews from the first study. We’re also grateful to have the continued support of NOGLSTP, and now oSTEM, too.
As an aside: We’d originally planned to announce the new study on Monday, but we held off for a bit in the wake of the horrific mass killing at the Pulse nightclub in Orlando. It’s hard to think that a project like Queer in STEM matters much, in the face of that kind of hatred. I do believe, though, that working to understand individual queer experiences — the nitty gritty details of our lives and careers — is part of the much bigger project of making society kinder to all people. The Pulse massacre is only the latest act of anti-queer violence to add to the fears that LGBTQ-identified folks carry with us every day — including in our laboratories and classrooms. I know I speak for all my collaborators when I say that we hope Queer in STEM can help to make those spaces feel safer.
We’ll officially open the new survey for responses on Monday, 20 June — look for notice here, on the study site, or on social media.
I got word this morning that the Encyclopedia of Evolutionary Biology, a huge compendium of current knowledge on evolution, systematics, and ecology, is now online. That’s exciting in and of itself, but it’s particularly so because it means you can finally see my contribution, the introduction to the topic of coevolution. Here’s the opening paragraph, of which I’m rather fond:
No organism is an island. Every living thing contends with predators, parasites, and competitors, and most also receive benefits from mutualists (Table 1). These interactions with other species exert natural selection—and predators, parasites, competitors, and mutualists may also experience selection in return. The mutual evolutionary change that results from this reciprocal selection is ‘coevolution’ (Janzen 1980; Thompson 2005).
The rest of the Encyclopedia includes contributions from a tremendous array of other authors, and I’m grateful to subject editor Andrew Forbes for the invitation to contribute. You can browse the whole thing on the publisher’s website, and download a manuscript-format PDF of the final text of my chapter here.