Saturday, June 26, 2010

Evolution 2010: Saturday

Today was a good start to Evolution 2010. This year as I describe talks I liked, I'm going to link to the abstract so you can check it out for yourself. Ironically, most talks I liked today don't have abstracts. Oh well, I tried.

I started the morning in a session on phylogeography then moved to phylogenetics & diversification before lunch. One highlight of the morning was Ben Warren's talk on the biogeography of Madagascar. He mentioned the recognized idea that the biota of Madagascar (and associated islands) is remarkably Asian in character. The most obvious explanation - that these Asian species must be leftover from the time before India split from Madagascar to crash into Asia - only works for some species (notably amphibians). Divergences of plants and birds are evidently too recent to explain this way. He's working on testing island hopping back across the Indian ocean. [ABSTRACT] See also his Cladistics paper just published.

The next interesting talk was from Sabrina Pankey, who is working on squid bioluminescence. That was really fascinating. She's trying to work out whether the light organs of sepiolid squids (like Euprymna) and loliginid squids (like Uroteuthis) are convergent. Can't wait to see more of that work. [ABSTRACT]

Then Joel Sachs gave a fascinating talk on Bradyrhizobium cheaters. Symbiosis theory suggests that mutualisms are dynamic relationships. Any time one of the partners develops the ability to benefit from the relationship without contributing anyhing (i.e. parasitize), then the cheater should increase in fitness. Sachs and collaborators have found that in Bradyrhizobium, these symbiotic cheaters do not arise from mutualists but from bacteria that apparently did not have the ability to form a symbiosis in the first place. Very interesting. [ABSTRACT]

The first afternoon session I attended was on genomics, and most of the talks were about repeats and noncoding DNA. Almost everyone talked about various functions these repetitive or noncoding sequences might have. Get it? Anyone else see the significance of talks on functional repetitive DNA at an evolution conference? Anyone? Steve?

The real shock of that session came from Junhyong Kim who spoke about SINE elements as dendritic localization signals in rat neurons. Not just any SINEs, mind you, but ID elements. I'm not kidding - they're called ID elements. So there you go: evidence of ID at an evolution conference. Not just any evidence, but functional SINEs. I can't make this stuff up. More importantly than the comedic value was Kim's approach. Not content to just identify a function for a type of SINE, he began thinking like a biologist. This SINE is weird, because not all dendritic mRNAs have this SINE, but they still localize to the dendrite. And not all copies of the ID element localize to the dendrite. Then it got worse: rats apparently have 100 times as many copies of this element as mice, which is really weird. There's a whole lot more to this story than just a functional SINE. I can't wait to hear more about this. [ABSTRACT]

The last session I attended was on systematics, where I learned about efforts to resolve the phylogeny of cicadas, isopods, and cormorants. I was mostly interested in the cormorants.

So that's day one. More tomorrow. Stay tuned.

Feedback? Email me at toddcharleswood [at] gmail [dot] com.