Sunday, July 8, 2012

Evolution2012: Sunday

This morning's sessions were pretty interesting.  I attended a speciation session first, then phylogeography before lunch.  To me the most memorable talk of the morning was Diogo Silva's research on an emerging pathogen of coffee, Colletotrichum kahawae.  Currently, the pathogen infects arabica coffee in subsaharan Africa, and it hasn't spread (yet) to other continents.  Silva is trying to determine where it came from, and his results implicate a group of related Colletotrichum pathogens from other species, which suggests that Colletotrichum emerged in part by a host shift.  As a creationist I'm intrigued by the origin of pathogens and pathology, and this certainly adds to our understanding of that intriguing subject.

I also quite enjoyed Luciano Beheregaray's presentation on Amazonian fish, which was extremely interesting and challenging.  He's found fish that occupy a flooded forest habitat (never the open river), but more importantly, there's pretty good genetic structure in the populations that correlate with tectonic changes in the area.  I found it challenging as I thought about the timescales involved and how his results might be explained from a creationist perspective.  I'm wondering more and more whether we will need to invoke a generally higher mutation rate in the past to account for such things.

In the afternoon, I attended a teriffic talk by Katharine Marske summarizing the work done in this Nature paper from last fall:

Species-specific responses of Late Quaternary megafauna to climate and humans

The interesting message for me was the fact that they could not detect a range restriction in woolly rhinos and mammoths prior to their extinction.  Mammoth extinction is something one of my students will be talking about at Origins 2012 in a few weeks, and we speculate that the mammoths may have exceeded their carrying capacity by so much that the population rapidly crashed.  We'll definitely have to have a talk about this paper when I get back.

Tonight, I'm going to Rosie Redfield's talk.  You might remember her from the arseno-DNA debate.  That should be good.

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