Mark Chase There are many literature resources available to molecular biologists wishing to assess genetic variation, but the myriad of techniques and approaches potentially available to the plant breeder and the evolutionary biologist is truly bewildering, and most have never been evaluated side-by-side on the same sets of samples. Additionally, it is often not recognized that tools that are useful for breeders can often be adapted for use in evolutionary studies and vice versa, but this is generally the case. The borderline between population genetics and phylogenetics is vague and difficult to assess, and a combination of both types of tools is best when it is not clear with which area one is dealing. Furthermore, it is not now appropriate to use just one type of marker in any kind of study; most markers have the potential to misinform under certain conditions, so it is always wise to incorporate at least two different types of assessments into any project. This volume is designed to facilitate this sort of multiple approach and provides comparative data on most currently available methods so that researchers can more intelligently select those appropriate to their area of interest, regardless of whether it is in the realm of breeding or evolutionary biology.