I actually have a good excuse for my slow production of new blog posts. The year 2009 is a landmark year in the history of evolutionary studies. February 12, 2009 is the 200th anniversary of the birth of Charles Darwin, and November 24, 2009 is the 150th anniversary of the publication of “On the Origin of Species.” To celebrate, VMNH is opening an exhibit today about Darwin’s travels in the Galápagos, and on the basic principles of evolution. I’ve been working on the evolution part of the exhibit for several months, and it has been taking up most of my time the last few weeks.
I’ve been teaching evolution in my high school and college classes in Virginia and Louisiana for 15 years, which, needless to say, can be a challenge. I’ve found, though, that for many undergraduate and community college students, the problem is that they have no idea what evolution actually is. To help overcome resistance to learning about evolution, I narrow it down to the barest basics: individuals are different (variation), differences are passed on to offspring (heredity), and individual differences determine reproductive success (selection). Those are all the basic underlying assumptions of evolution, and they are all pretty much common-sense; the most common reaction of my students is “You mean that’s it? That’s what all the fuss is about?”.
We decided to approach the exhibit the same way. We are a collection-based museum, so we try to use a lot of specimens, or at least images, in our exhibits. It’s pretty easy to show variation and heredity using specimens and photos; selection is a lot more difficult. By its very nature, selection requires time and multiple generations. Our planning committee came up with the idea of a simple computer-simulated organism that could evolve in response to external stimuli. I sketched out something like a sessile, stick-figure crinoid, in which certain stick lengths would be selected under a small number of variable conditions. However, no one at the museum had the programming skill to produce this simulation.
Fortunately, while we were planning the exhibit last year, I met Carol Burch-Brown and Eric Standley from Virginia Tech’s School of Visual Arts; they were looking for help on their own Darwin-related activities (more on that later this year). During one of our meetings, I asked them if they could do something with the simulation. They put together a team of other faculty members and students at Virginia Tech and produced a simulation orders of magnitude more advanced than what I had envisioned.
They call their simulated organisms “doollis” (I had nothing to do with that!). The doollis’ morphology is defined by a complex genetic code that modifies a series of reference points, as well as surface color and pattern. Doollis have a maximum 10 second lifespan, and if they survive that long they get to reproduce.
The doollis’ environment varies in temperature, current velocity, oxygen content, and light levels, and they evolve in response to these factors. Last week, Carol and Eric installed the selection computers in the exhibit (top of page). I let the doollis evolve for about a week; the images below are from that run, with the earliest image first. (By chance, it happened that most of the photos I took were while it was dark in Doolli World.) Keep in mind these all evolved from a single ancestor:
Carol, Eric, and I are continuing to work on the simulation. They have programed in a lot of possible expansion, and we’re curious to see where this thing can take us.
Tonight, there is a members’ reception for the new exhibit; it opens to the public on Saturday, February 7, and runs until April 23.