Wednesday, October 31, 2007
A beautiful day in Auckland
It is a little hard for me to believe that I only just got here yesterday. Maybe that's due to the incredible hospitality of the Rainey family, or maybe it's the eerie, chimeric familiarity of the place; but when I realized today that it was Wednesday, and I got here on a Tuesday, the feeling was surreal.
Maybe it's the length of the days. I got up early this morning (as you might expect if you did a complicated bit of time zone math), so I've been going for a while. It was utterly clear and gorgeous, so I walked down the street to watch the sun come up over Hauraki Gulf.
It's quite a ways down to the water -- I think I dropped as much in elevation to the beach as I walked in distance from the house to the top of the stairs down. On the way, I was joined by an incredibly and aggressively personable little Siamese. Let it not be said that friendliness among Kiwis is limited to the humans. Quite to my surprise, the cat followed me all the way down the 200 or so stairs, and even came right out onto the beach.
Unfortunately for my camera-hogging little buddy, once we were actually on the beach I was quickly absorbed by taking lots of pictures of really boring things, like rocks and limpets and seaweed. Before long, Kitty had disappeared and I had only mollusks for company.
By the time I made it back to the house, Paul was up. We had a spot of coffee and were off to the lab, where he gave a really interesting talk on the evolution of multicellularity. This is quite a paradox given our current assumptions about how evolution works, and is an area of special interest to me. The fundamental problem is that, any time you have a group of organisms that trade a little personal benefit for the good of the whole, there is a tremendous incentive for cheaters to arise and reap the benefits without paying anything in to the pot. Since the cheaters end up gaining the most, they multiply the fastest and cooperation breaks down. This has been repeatedly demonstrated experimentally and even holds true to an extent in my old co-op!
So how do you maintain cooperation? Obviously it happens all the time; there are loads of symbiotic interactions in the natural world, and plenty of cooperation at higher levels of complexity (like co-ops). For multicellular organisms to happen in the first place, something had to have gotten past this stage about half a billion years ago (in fact, evidence points to at least a dozen independent origins of multicellularity). The fact that our current models of evolution have a hard time dealing with these things suggests that there's some room for improvement in the model, and this is largely the kind of question I hope to look at in my PhD thesis. It turns out that some of the bacterial systems that Paul uses for experimental evolution offer some unique and interesting ways to check this kind of thing out.
The key is that Paul's lab has a bacterial strain that, under certain conditions, will reliably evolve from free-living, independent cells to a cooperative mat of cells. Equally reliably, and with enough time, cheaters will evolve and eventually destroy the cooperative mat. Since the mat uses resources more efficiently than independent cells, it will re-evolve, and then re-collapse, and so on. Hopefully, by playing around with different evolutionary pressures, Paul's team will be able to discover important new things about how evolution plays out in these scenarios. Their data so far sure are fascinating.
And heck, maybe I'll be part of that team. Sure is a nice place, and good people (and cats)!