Saturday, July 01, 2006

The Virtues of Inbreeding

At each site, we’ve been joined by guest faculty members from various institutions. Larry Kirkendall from the University of Bergen and Andy Suarez from University of Illinois joined us at La Selva. I’ll return to Andy’s research in another post. Larry is doing research on the bark beetles of La Selva and gave an intriguing lecture on inbreeding in evolution. Turns out sexual reproduction carries significant costs to a species. The least technical of these including the shear energy it takes to attract, court and mate, exposure to disease, the limited net contribution of males to reproduction and the fact that the most successful genes are always being diluted with less successful genes. Inbreeding (as well as asexual reproduction) avoids these costs. In some bark beetle species, for instance, mating takes place prior to dispersal so the costs of courtship are extremely low. Of course the downside of inbreeding is that genetic weaknesses are passed to all individuals and extremely difficult to overcome. Larry has learned that these bark beetle species, as well as many other species that inbreed, have passed through a narrow evolutionary window wherein their populations found a sufficiently successful gene recipe to enable long term survival in the absence of genetic mixing.

After one or more initial lectures faculty members lead subgroups in field projects in their area of expertise which are in turn presented back to the full group. The result being we are all exposed to the faculty member’s area of expertise from a variety of angles. It’s a great way to learn.