I’ve discovered a couple of important things at this meeting.
One, late night sessions at west coast meetings are deadly for any of us coming from more eastern time zones. At least the morning sessions are low stress.
Two, I haven’t heard one Drosophila talk yet, and the message is clear: we’re now in the stage of evo-devo in which everyone is diversifying and chasing down a wide array of species. There was a bit of model-system bashing, but at the same time, everyone is acknowledging the crucial role of those traditional, but weird and derived, lab critters in providing a point of comparison and being the source of many of the tools being used to explore phylogeny now. I thought, though, that the smartest comment of the evening was that now everything is a model system.
I’ve got some dense piles of notes on the evening session, but I’m going to give you the short version of everything, with an emphasis on the novel twists.
Michael Akam talked about segmentation genes, which every developmental zoologist now knows inside and out — trust me, this is a familiar topic with over 25 years of detailed research … in Drosophila. Akam made the point that now it’s looking clear that three of the major segmented phyla, the arthropods, annelids, and chordates, may be using related genes to accomplish segmentation, but they seem to be using different mechanisms — so he considers the question of whether segmentation in these three is homologous is still an open question. He also discussed recent work on the centipede Strigamia (definitely not a lab animal: they can’t breed them in the lab yet, so all the work is done by collecting embryos in the field, in Scotland). They have a dynamic pattern of segment addition that is very different from what you find in flies, and more similar in some ways to chodate segmentation.
Chelsea Specht talked about floral evolution in the Zingiberales. I’m an animal guy, so even the most basic stuff in this talk was entirely new to me. I know the general rules of the spatial development of in the fruit fly of the plant world, Arabidopsis, and she gave us a bit of context there, reminding us of the concentric development of sepals, petals, stamens, and carpels. The Zingiberales are a large and diverse group of plants that includes bananas and ginger, and one characteristic is an extravagant modification of the canonical pattern, with extra stamens, a loss of select stamens, and a fusion of stamens to form a novel structure, the labellum, which in these plants functionally replaces the petals. So of course they’re looking into the genes involved in the patterns, which turn out to be the familiar Arabidopsis genes redeployed in new patterns.
Paul Sereno had a talk that took a very different tack, and was unfortunately giving it at the equivalent of 11:00pm Minnesota time, so I’m sorry to say I didn’t follow it carefully. He was discussing the analysis of morphology, and was advocating the development of tools and techniques to compare data sets in addition to the usual output, phylogenetic trees. He was making the case that a lot of morphological studies are actually very poor (a creationist in the audience would have loved it, largely because he wouldn’t have understood the context) because the input data sets of different studies are not comparable.
And now I have to get back to work and listen to the next set of talks.