Genome Scanning for Quantitative Trait Loci

Understanding associations between phenotype and genotype is a key to understanding biology itself. We can observe high levels of structure and organization at all levels of phenotype, but the underlying genetic machinery has not been designed - it has fallen into place in a random fashion, and has then been directed by the forces of natural selection.While growing knowledge narrows the gap between phenotype and genotype, a lack of linear relationships is quite obvious. There are numerous and clear indications that even the classical dogma of one gene-one protein does not work in many cases. However, understanding this general situation does not prevent numerous successful attempts to identify certain links between genes and traits, including quantitative traits.This chapter relates to the detection and location of genes that cause some of the quantitative variation in phenotypes.