the much stronger evidence that has been
compiled in the past three years by Brian
Hare, Michael Tomasello and Josep Call,
but even this work says nothing about the
content of a chimpanzee?s beliefs.
A second problem is that research on the
developing theory of mind goes well beyond
the literature reviewed by Keenan, and raises
significant problems for his theory. Specifi-
cally, it is now clear that for many cognitive
capacities, including the theory of mind,
children have implicit knowledge long before
it is explicit;using an explicit measure such as
the mirror test might cause us to miss an 
earlier capacity.Furthermore,part of the chal-
lenge for the child in acquiring an explicit
theory of mind is that it requires consider-
able executive control,something that young
children lack because of the relative imma-
turity of the frontal lobes. This means that a
child?s inability to understand what others
believe is not necessarily a reflection of the
challenges it faces in attributing similar or
different beliefs to others;rather,the difficulty
may stem from the challenge associated with
inhibiting personal beliefs in order to make
accurate judgements about others.
Third,even if our sense of self is located in
the right hemisphere ? and there is chau-
vinism against this side of the brain from
neuroscientists who think that the left hemi-
sphere does all the heavy intellectual lifting
? this does not help our understanding of
how the brain generates a feeling of personal
experience, of guilt, awe, shame or despair.
It wouldn?t help us to understand why Shelby
is distraught,or whether medical technology
might someday reverse these cases of brain
damage.
In the end, however, Keenan and his co-
authors have assembled a rich set of evidence
that will contribute to what is certainly one of
the most interesting topics in the sciences of
the mind: our sense of self. At least, that?s
what I think, I think. n
Marc Hauser is at the Primate Cognitive
Neuroscience Laboratory and the Department of
Psychology, Harvard University, Cambridge,
Massachusetts 02138, USA.
A flexible theory 
of evolution
Developmental Plasticity and
Evolution
by Mary Jane West-Eberhard
Oxford University Press: 2003. 720 pp. $100,
?79.50 (hbk); $49.95, ?37.50 (pbk)
Gerdien de Jong and Ross H. Crozier
It is an ancient truism that what evolves is
the developmental system, from which it
follows that genetics, development and evo-
lution are interwoven. Genetics and evolu-
tion were integrated long ago in the synthetic
theory of evolution; development has only
lately rejoined the evolutionary fold. The
field of evolutionary developmental biology
thus created is mostly concerned with pat-
terns of evolution, comparing the genetic
basis of evolutionary changes in develop-
ment, rather than with the dynamics of
evolutionary changes. Its sister, develop-
mental evolutionary biology, studies how
selection works on development to produce
the adaptive phenotype, necessarily becom-
ing linked to evolutionary ecology. This 
is a field worth pursuing, and Mary Jane
West-Eberhard?s Developmental Plasticity and
Evolution certainly belongs within it, but
the question is whether the book does the
field good service.
For West-Eberhard the phenotype is 
central. But this is not the bleak ?genotype&
environment4phenotype? taught to first-
year students, but rather a vibrant, living,
changing phenotypic whole, far from dreary
genetic determinism. The phenotype is
developmentally plastic, changing in many
ways in response to many environmental
challenges. To be alive is to be developmen-
tally plastic. West-Eberhard envisages a syn-
thetic theory of evolution and development
in which environmentally induced pheno-
typic change gives rise to adaptive evolution
as readily as, or even more readily than,
mutationally induced phenotypic change.
The main evolutionary process, in West-
Eberhard?s universe, involves environmental
change, phenotypic accommodation and
genetic accommodation. An environmental
change elicits a developmentally plastic
response, and phenotypic accommodation
? the immediate adjustment to a change
resulting from the multidimensional adap-
tive flexibility of the phenotype ? ameliorates
its harm to individuals. New phenotypes
resulting from this developmental plasticity
are selected. A change in allele frequency ?
genetic accommodation ? improves and
incorporates the change.In this way the envi-
ronment becomes a crucial participant in the
generation and selection of adaptive design.
In West-Eberhard?s view, this sequence of
developmental plasticity,phenotypic accom-
modation and genetic accommodation is the
mechanism responsible for (nearly) all
books and arts
16 NATURE | VOL 424 | 3 JULY 2003 | www.nature.com/nature
Spot the difference: the water flea Daphnia readily changes shape in response to its environment.
Science, Money, and Politics: Political
Triumph and Ethical Erosion
by Daniel S. Greenberg
University of Chicago Press, $20, ?14
??the value of this book [is] as a unique and
revealing perspective on the way that the
science-funding process actually works in
Washington. The picture it paints is not a
flattering one. But ? unlike many of those he
writes about ? Greenberg is not out to make
friends in high places.? David Dickson, Nature
413, 355?356 (2001).
The Future of Life
by Edward O. Wilson
Abacus, ?8.99
?[Wilson] accurately and passionately tells the
story of the disappearance of many of the only
living beings we know of in the Universe ?
key components of humanity?s natural
capital.? Paul R. Ehrlich, Nature 417, 21?22
(2002).
Secret Agents: The Menace of Emerging
Infections
by Madeline Drexler
Penguin, $15.00
New in paperback
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evolutionary novelty, adaptive radiation,
speciation and macroevolution. Evolution
proceeds through adaptive developmental
phenotypic plasticity.
Mainstream evolutionary biology is rid-
dled with genetic determinism, blocking a
biological view of the organic phenotype,
West-Eberhard suggests. However, many of
the biological studies she adduces in her sup-
port belong to the mainstream. Nobody
objects to ?a unified Darwinian theory that
relates developmental plasticity to genetic
change?, but it is a matter of proportion.
West-Eberhard sees too much unwarranted
emphasis on genes; many will see an unwar-
ranted role for developmental plasticity in
her argument, as the description of pheno-
typic plasticity itself is too general and vague
to get to grips with.
West-Eberhard?s conviction of the pri-
macy of the environment as the inducer of
new phenotypic variation runs through the
book, making her ask for a coherent evo-
lutionary theory that uncompromisingly
includes the environment alongside the
genome in all aspects of evolutionary
thought. She accepts that genetic change
accompanies evolution, but only as genetic
accommodation follows environmental
induction; evolution as genetic change ?is
left hanging by a tenuous thread?. In this
view,genes are followers,not leaders.
How plausible is all this? Not very. No
convincing evidence is presented for adap-
tive phenotypic accommodation to a new
environment. Genetic accommodation is
just a classical adaptive change in gene fre-
quency. Developmental plasticity exists and
is important in nature, but for it to be the
dominant evolutionary factor, one has to
show that developmental plasticity is pre-
dominantly adaptive and precedes genetic
adaptation.
West-Eberhard refers to much good biol-
ogy, but fails on the major point: develop-
mental plasticity as the initiating factor of
adaptive novelty preceding genetic change.
The evidence shows that much developmen-
tal plasticity exists and has a genetic basis, no
more and no less. West-Eberhard concedes
that direct examples of adaptive environ-
mental induction are lacking, but she labels
many cases as indirect evidence reflecting
the process. Whether the environment is the
main player in eliciting adaptive develop-
mental plasticity, and thereby in all other
evolutionary processes, remains a question
of faith. No crucial laboratory experiment is
suggested that would test whether environ-
mental induction leads to adaptive evolu-
tion. Actually, some tests for phenotypic
accommodation (as ?beneficial acclima-
tion?) have been done by Raymond Huey?s
group at the University of Washington, and
were negative.
In one of the first studies of phenotypic
plasticity, Richard Woltereck defined the
reaction norm as the range of the pheno-
types that an individual could exhibit over all
environments. The original insight was:
?Genotypus4Reaktionsnorm?, the genotype
being the information for developmental
plasticity. Woltereck transplanted Daphnia
from Denmark to Italy to investigate
whether the environment modified the reac-
tion norm: it didn?t. Later, dissatisfied with
?materialism? but impressed with pheno-
typic plasticity, Woltereck wrote two books,
unfortunately incomprehensible, expressing
a holistic view. In reading West-Eberhard?s
Developmental Plasticity and Evolution, one
also often struggles with the verbal argu-
ments: what does this mean, and how, pre-
cisely,would that work? West-Eberhard asserts
a vision but presents little analysis. A major
new synthesis and research programme this
book is not. n
Gerdien de Jong is in the Department of
Evolutionary Population Biology, Utrecht
University, Padualaan 8, NL-3584 CH Utrecht,
the Netherlands; Ross H. Crozier is in the
Department of Evolutionary Genetics, School of
Tropical Biology, James Cook University,
Townsville, Queensland 4811, Australia.
The finger of Galileo
The Oxford Companion to the
History of Modern Science
Edited by J. L. Heilbron
Oxford University Press: 2003. 960 pp.
$110, ?40
Ryan J. Huxtable
The value of a person?s life is not to be
judged by the length of the obituary. How-
ever, more than 100 biographies of scien-
tists in The Oxford Companion to the
History of Modern Science are all approxi-
mately one page in length, regardless of the
achievement of the scientist or the amount
of information available about the person.
This modified egalitarianism is illuminating
not only of the subject at issue, but of cur-
rent attitudes towards personal achieve-
ment and great men or women. Linus
Pauling, who uniquely won two individual
Nobel prizes, made enormous contribu-
tions to several areas, including insights into
the nature of the chemical bond, and lived
to a ripe age of 93, still working on contro-
versial issues. Rosalind Franklin made an
important, but single, contribution to the
elucidation of the structure of DNA, and
died at the early age of 37. These two scien-
tists get the same consideration as Galileo.
By almost any measure, modern science
begins with Galileo Galilei (1564?1642). He
made enormous theoretical and practical
contributions to areas as disparate as astron-
omy and the measurement of time. He tore
down the dusty shed of aristotelian physics
books and arts
NATURE | VOL 424 | 3 JULY 2003 | www.nature.com/nature 17
that had blocked the daylight for so long. He
was also one of the first rational investigators
to fall foul of government and orthodoxy.
His entry in this book describes him as the
father of modern science, and the preface to
the book begins with a quotation from him.
Conspicuously absent is an entry on
Giordano Bruno, who was burnt at the stake
for his iconoclastic but rational views of
astronomy a few years before Galileo faced
the Inquisition.Who can doubt that Galileo?s
recanting of his ?heresies? of heliocentrism
was fuelled by the fire that consumed Bruno?
Bruno receives three mentions en passant,on
the influences on him, and on his views of an
infinite Universe and stellar distances.Bruno
was a hermeticist. Hermeticism, which does
get a deserved entry in this book, was a part
rational, part mystical system of thought,
significant in the development of modern
science. However, Galileo was surely the first
modern scientist.
The editor-in-chief, J. L. Heilbron, is a
witty and erudite contributor. His entry on
?ether?begins:?A possibly nonexistent entity?,
a description that in itself conjures up vari-
ous philosophical issues. Are Plato?s ?ideal
horses?entities? Heilbron is aided by 5 editors,
7 consultants and 217 contributors, in pro-
ducing almost a thousand pages of double-
column text.
The thematic listing at the front of the
volume of main headings and subheadings
was more useful than the index. Thus, an
index entry of page 357 for ?civil rights? leaves
the reader scanning two densely printed
columns in search of the elusive reference.
Some of the entries, such as that on
?progress?, seem overly general. Others seem
non-intuitive, such as ?tacit knowledge?,?shift
Galileo Galilei: making plans for the future.
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