GENE mapping is useful against all sorts of pests—including tree
thieves. Wood rustling is easy—just buy a chainsaw—and
profitable. In British Columbia, for example, illegal felling of
species such as the western red cedar is a growing problem. A
single tree can be worth C$24,000 ($16,000), the wood making its
way into fancy roof shingles and expensive cellos. The
provincial government also loses tax revenues; tree theft is
thought to cost it as much as C$20m a year. So Eleanor White, a
researcher at the Canadian Forest Service in Victoria, British
Columbia, has borrowed from forensic science and devised a way
to use genetic markers to “fingerprint” valuable trees so that
they can be traced if they are stolen.  To do this, Dr White has
developed a technique to extract DNA from dead wood using a
mixture of special solvents. She then proceeds much as the
police do in a forensic laboratory, amplifying the retrieved DNA
using a technology known as polymerase chain reaction, and then
cutting it up into millions of