Guardian | The origin of life is one of the great outstanding mysteries of
science. How did a non-living mixture of molecules transform themselves
into a living organism? What sort of mechanism might be responsible?
A century and a half ago, Charles Darwin
produced a convincing explanation for how life on Earth evolved from
simple microbes to the complexity of the biosphere today, but he
pointedly left out how life got started in the first place. "One might
as well speculate about the origin of matter," he quipped. But that did
not stop generations of scientists from investigating the puzzle.
The
problem is, whatever took place happened billions of years ago, and all
traces long ago vanished – indeed, we may never have a blow-by-blow
account of the process. Nevertheless we may still be able to answer the
simpler question of whether life's origin was a freak series of events
that happened only once, or an almost inevitable outcome of
intrinsically life-friendly laws. On that answer hinges the question of
whether we are alone in the universe, or whether our galaxy and others
are teeming with life.
Most research into life's murky origin has
been carried out by chemists. They've tried a variety of approaches in
their attempts to recreate the first steps on the road to life, but
little progress has been made. Perhaps that is no surprise, given life's
stupendous complexity. Even the simplest bacterium is incomparably more
complicated than any chemical brew ever studied.
But a more
fundamental obstacle stands in the way of attempts to cook up life in
the chemistry lab. The language of chemistry simply does not mesh with
that of biology. Chemistry is about substances and how they react,
whereas biology appeals to concepts such as information and
organisation. Informational narratives permeate biology. DNA is
described as a genetic "database", containing "instructions" on how to
build an organism. The genetic "code" has to be "transcribed" and
"translated" before it can act. And so on. If we cast the problem of
life's origin in computer jargon, attempts at chemical synthesis focus
exclusively on the hardware – the chemical substrate of life – but
ignore the software – the informational aspect. To explain how life
began we need to understand how its unique management of information
came about.
