Molecular Markers Should be Selectively Neutral Selective neutrality of molecular markers was one of the most debated observations of the isozyme era. Further, these electromorphs were seemingly different enough that they should have some selective importance. The literature battle was waged for several years around 1970, and ended when DNA sequence information became commonplace. Most molecular markers are selectively neutral, some represent adaptively significant mutations. With PIC values, the higher the more generally useful the marker.
Informative markers are useful for many applications.
Among these is providing relative estimates of genetic diversity. There are several ways to look at diversity within a germplasm pool, and a fine discussion of a few approaches was provided by Dillman et al., 1997. Comparison of RFLP and morphological distances between maize inbred lines. Nei provided a straightforward method of estimating genetic distance among lines. Nei's indices look at whether or not a band is present on a gel.