May 09, 2008

Yesterday's Festivities: Phylogeny Symposium and Such

Yesterday was consumed, happily enough, by attending the Plant Biology Initiative symposium at Harvard. As it was entitled Phylogeny Informs Biology, it probably comes as no surprise that the theme of the day was the many ways in which phylogenetic techniques are being applied to modern biology and the findings that are being produced because of this.

Traffic was awful and caused us to arrive a bit late which made us miss the opening remarks and the very beginning of Debashish Bhattacharya's seminar on endosymbiosis and the origins of plastids in eukaryotic cells. Nonetheless, I found it the most interesting session of the day (not to take anything away from the other presentations, I just find the topic particularly interesting). Erika Edwards presented her research on the application of phylogenetic techniques in sorting out the question of the importance of C3 vs. C4 photosynthesis schemes in grasses are involved in atmospheric carbon cycling through the investigation of biases in stable isotope utilization. After the first break, Lee Taylor presented on orchids of genus Corallorhiza, a devious bunch of plants that have gone from being a mutualist with mycorrhizal fungi to being a predator. In this genus, the plants have given up producing leaves and roots and the like and instead have taken to eating the hyphae that provide mineral nutrients in exchange for photosynthate in other orchids-fungus relationships. They're nasty things if you're a hapless fungal symbiont! In this instance, the driving evolutionary force is a jump between Thelephoraceae and Russulaceae, one which forms very neat clades under phylogenetic analysis. Again, Taylor's talk was particularly interesting to me because Thelephoraceae is a sister group to the polypores. Next up, David Hibbett spoke about automated taxonomy and particularly a program called MOR, which is currently under development.

The Harvard folks were very generous with lunch. Yes, they gave us sandwiches, but these were some particularly good sandwiches. My lab and members of the Pringle lab split off for a mycological luncheon in the herbarium. I learned that one of the graduate students in that lab is also doing work involving polypores, though she's looking at community structure. We'll probably be collaborating on some things, swapping specimens and collecting and the like. Funny how our paths keep crossing; I first met her in Oakland in 2000 or 2001, and now here we are on the other side of the country overlapping our work on clades that not many others are engaged with lately. Near the herbarium I noted the first mushroom fruiting bodies of the season, a number of very robust Pholiota, and now am particularly inspired to go collecting this weekend. It's a sign, I tell you!

After lunch, Susanne Renner spoke on the application of phylogeny to the question of the biogeographical diversification of plants, a session which ended with her declaration of the death of vicariance hypotheses in favor of tremendous pools of seeds limited not by dispersal but establishment. Then it was back to the grasses with Caroline Stromberg who spoke on her work using phytoliths to date the origin and diversification of grasses; it looks like they were already around by the end of the Cretaceous, pushing back their age by several million years beyond current estimates. Finally, the day's presentations ended with Michael Donoghue's talk on the application of phylogenetic analysis in resolving the evolutionary history of angiosperms, particularly Dipsacales. He also gave the concluding remarks before the symposium ended and the reception began. Donoghue is a very engaging and entertaining speaker and certainly was a good remedy to the sleepiness induced by the sporadic air conditioning in the room in which the symposium took place.

When all is said and done, it's interesting to see how large a role the reconstruction of evolutionary history plays in diverse aspects of biology and how it unites mycology, plant biology, paleontology and other such disciplines. As John Timmerman pointed out based on his attendance at an entirely different symposium, there really are controversies in evolutionary biology, but they're about the specifics, not about evolutionary theory itself. The theory, in fact, is what allows us to discover the evidence that resolves the controversies in evolutionary history, the specifics of what happens. The controversies we heard about yesterday — from whether or not the biogeographical history of grasses was driven by the rise of ungulates to whether the Cucurbitae originated in Africa or Asia — are questions for which evidence can be discovered, and not just when someone happens to find a fossil. Evolutionary biology in general is the basis upon which these histories can be reconstructed and resolved using molecular characters and biogeographical evidence. What's happening in phylogeny these days is really pretty amazing stuff for those who can make some attempt to keep up with it.

In fact, all anyone can do is make an attempt. There's so much new discovery and so much happening in general that it's probably not possible for anyone to stay on top of all of it. Still, one must make some attempt. Even a small fraction is a lot of knowledge. Anyone who says that there's "no evidence" for evolution can be accurately assessed as someone who refuses to look for any by even doing so much as reading a paper every so often.

In his concluding remarks yesterday, Michael Donoghue said that these were exciting times. He's right, but maybe a bit conservative in his verbiage. I'd call them frenetically hyperactive times, exciting in proportion to their subject matter to the same extent that jumping out of an airplane is proportionate to pedaling a tricycle.

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