Graphical population genetics - the geometry of genetic structure


Graph of Sonoran Desert columnar cactus Pachycereus schottiiIn collaboration with Dr. Rodney Dyer (Virginia Commonwealth U.) we have developed population graphs, a novel network-based procedure for quantifying patterns of inter-population gene flow (Dyer & Nason 2004; Dyer et al. 2010). While most population geneticists recognize that gene flow is probably best represented in the form of interacting networks of populations, in boiling down this complexity to one or a few summary statistics (e.g., Fst) most of our analytical procedures fail to capture the spatially-explicit connectivity among populations that we are often most interested in. A population graph, in contrast, provides a formal statistical model of the network of the effective gene flow - the genetic connectivity - among populations. Software for both the construction and visualization of population graphs is part of the GStudio R package written by Dr. Dyer.  The network of population genetic structure revealed by population graphs has been an important component of several of our papers (e.g., Dyer & Nason 2004; Krafsur et al. 2005; Garrick et al. 2009a; Dyer et al. 2010).