Community genetics in the Northwestern Atlantic intertidal.

Our ability to make inferences about the processes acting upon a biological system can be dramatically improved through integration of information from other fields. In particular, this is true of the field of phylogeography, a discipline that attempts to describe geographical variation in species using neutral genetic diversity as a correlate of time. Through comparisons of information from multiple species, as well as background information about the abiotic environment and how it has changed over time, we should be able to reassemble many of the forces that were important in assembling the communities and community interactions found in a given region. Here I review the information available for coastal species in the northwestern Atlantic, and argue that an integration of ecological, genetic, geological and oceanographic information can illustrate emergent patterns of community genetics.