Thursday, September 26, 2013

EvoDevo begins in Venice!

Maryna P. Lesoway | PhD Student | Abouheif Lab

I’m in Venice this week, participating in a week-long summer school at the Instituto Veneto di Scienze Lettere ed Arti. This is the third edition of the course, which brings together students and investigators interested in evolutionary developmental biology (EvoDevo). 

Instituto Veneto di Scenze Lettere ed Arti
We’ve already completed four days of the course, which the instructors have been asked to structure as a discussion of what we don’t know in EvoDevo. The idea is that science is really driven by asking questions about things we don’t fully know or understand, can be a much more useful approach than simply re-stating what is already understood, particularly from a teaching perspective. And if the goal of science is to increase our understanding of the world that we live in, we need to ask good questions!

It has proven to be a much more challenging approach than a more typical organization, particularly to learn that many of the foundations that we take for granted are not nearly as stable as we generally think. For example, we’ve spent a great deal of time talking about evolutionary family trees – phyolgenies. These are trees that tell us how species relate to one another and give us a better understanding of how characters have evolved through time (i.e. the direction of change). These are incredibly powerful tools for evolutionary developmental biology, but we often assume that published trees are set in stone. Or at least in wood, to stay with the tree metaphor. However, these are really just our very best guesses, and even with lots of data and good evolutionary models, we still can’t accept them at face value. Even when we build trees using genomic approaches, which means using even more data, is really difficult because we are often asking questions about what evolved hundreds of millions of years ago. And adding fossil data it is often insufficient for understanding evolution on these very long time scales. Maybe we’ll be able to resolve this, but maybe we can’t. 

I’m learning incredible amounts of information, but also about how little we really know about development’s role in evolution. This field have been an area of active research for at least the last twenty to thirty years, and although we have answered many questions, we have raised even more. But, we are also developing new techniques, using greater diversity of animals as models for development and evolution, and changing views about how development integrates into evolutionary theory. It may seem a bit discouraging at times, to think of all the work that has been done, and what a long way there is to go yet, but at the same time it is incredibly exciting. As was quoted one of today's lectures, we may be as confused as ever, but at least it is now on a higher level, and about more important things! 

Venice is also the home of the spandrels of San Marco, made famous in evolutionary biological circles by Gould and Lewontin’s criticism of the adaptationist paradigm – how structures don’t have to be “for” anything, much like the spandrels in St. Mark’s Bascilica here in Venice – the spandrels are a structural result of having a dome centered over an arch, and have not been produced with the express idea of being surfaces to decorate with angels. In biology as well, many features may simply be a result of developmental or structural constraints, rather than an adaptive outcome. And yes, the spandrels of San Marco are beautiful!