In gene mapping, any sequence feature that can be faithfully distinguished from the two parents can be used as a genetic marker. Genes, in this regard, are represented by "traits" that can be faithfully distinguished between two parents. Their linkage with other genetic markers is calculated in the same way as if they are common markers and the actual gene loci are then bracketed in a region between the two nearest neighboring markers. The entire process is then repeated by looking at more markers that target that region to map the gene neighborhood to a higher resolution until a specific causative locus can be identified. This process is often referred to as "positional cloning", and it is used extensively in the study of plant species. One plant species, in particular in which positional cloning is utilized is in maize. The great advantage of genetic mapping is that it can identify the relative position of genes based solely on their phenotypic effect.