BOOK I
What
Is
Life?
REVIEW
-More
sophisticated
Reconsidered*
basic
idea
by
J
theories
were
B
S
Gadagkar
of
complex
including
in
F
Cambridge
University
Press, 1985.
earth
1953
g ave
Since
there
into
one.
While
guished
of the
origin
there
have
been
for
theories
origin
and
supporters
extra-terrestrial
transport
of
scientific
life
leading
to
more
convincing,
the
As
it
beliefs
about
to. Charles
style
"But
in
Darwin
oh,
some
warm
whose
little
present,
present
day
devoured
the
chemically
more
such
we
that
matter
be
which
would
not
case
living
creatures
to
origin
from
Bulletin
In
ways
replication
was
was
that
likely
to
of
has
the
nonofRNA
thus
the
have
of,genetic
replication
with
the
realized
problem
and
which
undergone
carrier
world
more
without
soon
primitive
The
nucleic
in
have
It
synonymous
virtually
problem
of the
of life..
the
have
which
were
Trinity
of
.occupation
Sc~ences.
88
of
to
the
of
modification
of molecular
attention
possible
may
a
as the
and
of
pre-biotic
physicist
with
advent
DNA
form
ofDNA
synthesis
synthesis
the
become
formed."
*Reprinted
more
enzymatic
in
instantly
or absorbed,
before
all
at
the
formed
to
shifted
acids
than
information.
light,
ready
changes,
would
could
the
form
rather
been
a protein
formed
complex
to
Miller
leaps
together
precursors
enzymes.
RNA
the
chemical
crude
the
chemically
discovery
their
nucleic
of
innumerable
theoretical
naturally
and
.
theorIes.
of
got
and
pre-biotic
acids
aid
go
with
salts,
quite
some
earth
if)
biology
primitive
present
pond,
etc.,
was
events
inimitable
a big
material
importantly,
primitive
on
electricity,
still
on
life
phosphoric
more
possible
of
and
compound
if
a
The
Miller
these
been
these
have
cell.
genetic
the
up
how
might
primitive
remaining
built
our
what
distin-
simulated
Stanley
to
impressive
imagining
molecules
subsequent
life
in
old
suggesting
often,
of ammonia
undergo
been
of
so
origin
if(and
coJlceive
-heat,
origin
the
back
some
of the
happens
is a very
the
has
reconstruction
earth.
~rts
earth,
community
progressively
complex,
to
of life
abiological
in
modifications
and
The
molecules
by
have
and
experiment
problem
acids
boost
and
1920's.
of
conditions
a major
then
extensions
The
the
biological
amino
primordial
y reeman Dy son
b
in
this
A IOparin
demonstration
synthesis
Originsof life
by
Haldane
experimental.
Raghavendra
embodying
formulated
fresh
delightful.
is
based
on
College,
Freeman
air.
Dyson
present-day
his
book
under
Tarner
London,
the
Dyson
brings
correctly
review,
lecturers
molecular
at
well-known
in
a breath
attributes
replication-centered
of
-"\N\j\",~
little
biology
the
pre-
to
Erwin
RESONANCE
I February1999
BOOK I REVIEW
Schrodinger's advice to biologists to inves-
willing to call it a theory), metabolism or
ligate the molecular structure of the gene.
proteins evolved first, and once this crude
But then why did Schrodinger call his book
hardware was available, nucleic acid or the
What is life?
Because, says Dyson, Schro-
software evolved in a second step. In today's
dinger equated life with 'replication' and
neglected to worry about 'metabolism'
(perhaps wisely at that time, asMukunda has
organisJDsnucleic acidsareneededfor protein
synthesis and proteins are needed for nucleic
acid synthesis. So which came first, the
argued in the accompanying
review of
chicken or the egg?Dyson clearly prefers the
Schrodinger's book). But Dyson argues
convincingly that the time has now come to
chicken (= metabolism or protein) for step
one and argues that a primitive form of life
once again ask "What is life?" and focus this
time around on 'metabolism' rather than
consisting only of protein must have arisen
first, growing, metabolising and reproducing
replication.
in some crude fashion before nucleic acids
came along in steptwooApart from its logical
ongtns
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suggest
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yson
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e never
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ary
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77
IS m Just
pages
fi ~
or.
The accumulated
wisdom of the variations of the Stanley Miller
has
readily
D
h o h
IS
ypot
yson
h
d
oes
0 0
eSlS m
k
at more
conditions
but
nucleotides,
h
-w
embarrassment
been
that
in
simulated
amino
acids
are
pre-biotic
nucleic
are
much
acid
harder
bases,
let
to come
alone
by.
If
etween
1 0
y JO
a
ho 1
0 All
ho
0 1 d h ol
Istonca an p 1 osop lca perspective.
b
an acute
0
to expenmentallsts.
formed
a p easure
to
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a ways
been
00
h
h
t
h
es
has long
0
0
.experiment
to expenmental1sts.
approaches
1
reasonableness,this sequencemakes senseof
can one as
only proteins
0 0
pre-bl0tlcally
0
0
0
proteins,
the
needed to have been produced
0
0
.0
and
o.
mslde pnmltlve
nucleic
"
acids
orlgmated
0
0
cells already contammg
experimental
findings
make
perfect sense.
Dyson's main thesis is that life originated
twice, not just once. First he makes a very
convincing case for the distinction between
what he calls replication (= nucleic acid) and
metabolism (= protein). Borrowing on von
Neumann's analogy, he equatesnucleic acid
Buthowdidtheprimitive'protein'organism
get along without nucleic acids? Dyson
recognises that they must have been beyond
the reach of Darwinian natural selection
becausethey could not have reproduced with
any level of precision. He therefore uses
to softwareand protein to hardwareand reminds
us that hardware logically comes before
Kimura's neutral theory of evolution to deal
with these primordial 'cells'. But it is Dyson's
software. So in Dyson's hypothesis (he is not
treatment of the subsequentevolution ofRNA
RESONANCE I February 1999
-JV\Mf\I--
89
~~~
BOOK I REVIEW
as a parasite that is most appealing in the
can possibly catalyze their own replication
context of present-day evolutionary biology.
IfRNA (or DNA) is the software it can exist
as a parasite on the hardware without
have led somebiochemists to believe that the
chicken and egg problem has finally been
solved in favourofRNA but I would hazard a
contributing anything in return. That is
precisely what most present-day viruses do.
guessthat such a conclusion is too premature
-the logic in Dyson's arguments (in favour of
The primitive RNA must have started off as
a parasite until the protein-based life "learned
protein) is so compelling that we need to
tread here with caution. At the very least,
to make use of the capacity
more biochemists should read Dyson
for exact
replication which the chemical structure of
RNA provided" and "The primal symbiosis
b dI
d
' , RNA
f
0 protelll- ase lie an parasltic
grew
.
gradually
' +"
into
a harmonious
unity,
the
modern genetic apparatus".
Recent findings that RNA molecules can
sometimes have enzymatic properties and
~ "I
'
'
Bangalore 560012, India,
and
Evolutionary
andOrganismal
BiologyUnit,Jawaharlal
NehmCentreforAdvancedScientific
Research,
Jakkur,
Bangalore
560064,India,
Email: ragh@ces,iisc,emetin
The way to solve the conflict between human values and
technological needs is not to run away from technology. That's
~
J'
RaghavendraGadagkar,Centre for Ecological
SClences,
'
I ndIan I nstltute
'
0f
Science,
II
impossible. The way to resolve the conflict is to break down the
barriers of dualistic thought that prevent a real understanding of
what technology is -not an exploitation of nature, but a fusion of
nature and the human spirit into a new kind of creation that
transcends both. When this transcendence occurs in such events
as the first airplane flight across the ocean orthe first footstep on
the moon, a kind of public recognition of the transcendent nature
of technology occurs. But this transcendence should also occur
at the individual level, on a personal basis, in one's own life, in
a less dramatic way.
Robert M Pirsig
90
-JVV'J\fv-
RESONANCE
I February
'.
1999