ABSTRACT
This chapter is concerned with mutation, which is the ultimate source of all genetic diversity, and about the resulting kinds of differences at the DNA level which exist between people. In general, cell cycle progression is tightly coordinated with DNA repair and cell survival or death through a network of genome surveillance pathways. A simple base-substitutional difference between two human DNA sequences can be given a number of different labels, and unfortunately the rules for applying them are not always clear or consistent. The search for human genome variation and the development of methods to analyze this variation in large numbers of samples has been driven by the desire to identify genes responsible for genetic disorders. A good estimate of mitochondrial DNA mutation rate is important for human evolutionary genetic studies. In the case of mitochondrial DNA, the primary calibration comes from dividing the sequence divergence between humans and chimpanzees by the time since they diverged.
