The analysis of DNA from ancient material is a recent technological advance that has produced and promises further important scientific insights. It has also inspired the popular book Jurassic Park, by Michael Crichton, and the film of the same name. DNA is, fundamentally, a chemical that can survive after the death of the organism that carried it. It is a relatively stable chemical compared to the proteins found in the cell, although it can be fragmented and destroyed by chemical processes, such as oxidation in air, and biological processes, such as digestion by enzymes produced by bacteria. If DNA can be extracted from ancient specimens of dead material, then, in theory, it can be analyzed in the same manner as DNA from living organisms. The first DNA to be extracted from an ancient specimen was from 150-year-old tissues from the quagga, an extinct relative of the...