Full of Sound and Fury: History of Ancient DNA

The discovery that DNA survives in ancient remains and can be amplified by the polymerase chain reaction has added a direct temporal dimension to evolutionary studies. Initial reports suggested that the time period open to investigation was vast, extending back into the Cretaceous period. However, attempts to replicate of results involving DNA purported to be over a million years old have not succeeded. Theoretical studies suggest that DNA is unlikely to survive intact more than about 100,000 years. However, even over this time period, the evolutionary questions that can be addressed are far reaching and include systematics, paleoecology, the origin of diseases, and evolutionary processes at the population level.