The realisation in the 1980s that DNA is sometimes preserved in
very ancient biological specimens opened up a new field of
research within evolutionary biology. Ancient DNA can be seen as
a time machine that opens up a window to the past, enabling us
to trace molecular evolutionary processes through time and
space. Although the questions that can be answered by studying
ancient DNA are limited by the degree of DNA preservation, it
can be a very important and powerful source of information. For
example, it allows us to: Ancient DNA analysis is being
increasingly incorporated into research addressing questions
relating to: Find out what conditions suit the preservation of
ancient DNA. Learn about quality and contamination issues and
how these can be overcome. Ancient DNA can be described as any
DNA extracted from ancient biological specimens, such as
archaeological bones, teeth or other tissue. Ancient DNA can
derive from a wide spectrum of sources, including: