Saturday, June 11, 2005
Cultural Transmission of Fitness
It was more or less by chance that I read the recent article by Heyer, Sibert and Austerlitz in the April issue of Trends in Genetics about what they call cultural transmission of fitness as carefully as I did. I had it with me on a plane today, and the seats on Northwest Airlink were just too close together for me to get out my laptop. CTF is the nongenetic transmission of fitness, and they make an intuitively compelling case (PubMed) that CTF can have a huge effect on effective population size and coalescence times. Their model appears applicable not only to the transmission of true culture in human populations, but also to epigenetic changes and artificial selection. It's not every day that a new idea in population genetics is articulated, and I found this fairly exciting. However, the idea is more a formulation of ideas that I've been vaguely aware of for a long time than an entirely new idea. This does not to take anything away from them; a formal statement of a phenomenon and its consequences is what constitutes progress in population genetics (the real work is presented in Sibert, Austerlitz and Heyer, Theoretical Population Biology 2002; PubMed). Furthermore, their citations suggest that the idea has been around for a while (although it's new to me). In fact, the applicability of this model to my previous post has apparently already been tested and rejected ("CTF was [not detected] in Ashkenazi Jews")!