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Does evolution have a structure, an overall
design, perhaps even a purpose? Orthodox opinion recoils
from this prospect. Evolution, it is widely believed, is
an effectively random process where almost any outcome is
possible. Freeze the tape of life, and now we see dolphins
and tulips, ants and mushrooms, even humans. Rerun the tape
and, it is claimed, evolution would follow completely different
pathways; no tulips or ants, and certainly no humans. We,
like all other life, are an evolutionary accident. But is
this correct? In fact the evidence points in exactly the
opposite direction. Not only does life have an uncanny knack
of navigating to precise solutions, but it also repeatedly
returns to the same solution. By no means all is possible
in evolution. We know this because of the ubiquity of evolutionary
convergence, which unexpectedly reveals a deeper structure
to life.
In this extraordinarily wide-ranging book
Simon Conway Morris takes us on a tour of life that encompasses
both classic examples of convergence, such as the camera-eyes
of octopus and human, and remarkable new work that shows,
for example, how ants have developed agriculture independently
of us. Embedded in the evolutionary process are both latent
inevitabilities and pathways that will be repeatedly explored.
Underpinned by DNA, the weirdest molecule in the Universe,
guided by a genetic code of staggering effectiveness, the
tape of life will in time navigate to such biological properties
as advanced sensory systems, intelligence, complex societies,
tool-making and culture. So if these are all evolutionary
inevitabilities, where are our counterparts across the Galaxy?
The tape of life can run only on a suitable planet, and
here it turns out that such Earth-like planets may be much
rarer than is hoped. Inevitable humans, yes, but in a lonely
Universe.
Simon Conway Morris is Professor of Evolutionary
Palaeobiology at the University of Cambridge. He was elected
a Fellow of the Royal Society in 1990, and presented the
Royal Institution Christmas lectures in 1996. His work on
Cambrian soft-bodied faunas has taken him to China, Mongolia,
Greenland and Australia, and inspired his last book The
Crucible of Creation (1998).
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