THE human race has spent millennia celebrating, damning and
defying old age. But understanding it, from a scientific
standpoint, has long proved elusive. Why does the body alter so
dramatically with time? In the past decade, new tools and fresh
ideas have started to give researchers a grip on the “what” of
ageing—the complex changes that go on within the body's cells
over time. They even have some inkling as to the “how” of
ageing, the biochemical processes which may trigger these
cellular phenomena. But why the body should become more prone to
these pressures in the first place is much debated. Ageing is
one of nature's almost universal phenomena—virtually all
multicellular creatures, if given a chance, will go through the
process—but still one of its most mysterious.  A distinct
process  Non-scientists tend to think of “ageing” as a
continuous, lifelong process, a series of changes from
childhood, or indeed conception, onwards. Most biologists have a
different view. They see the period of ageing as one dist