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Individual development and evolution The development of novel behavior. By Gilbert Gottlieb. New York Oxford University Press. 1992. 231 pp. ISBN 0-19-506893-9. $35 (cloth)

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Book Reviews
genesis”). It is clear to Gottlieb that the fault
for the exclusion of developmental studies
THE from the field of evolutionary biology lies
By with the geneticists.
Gilbert Gottlieb. New York: Oxford Uni. . . [Wlrongheaded thinking about the process of
versity Press. 1992. 231 pp. ISBN 0-19epigenesis itself kept alive a preformation-like
506893-9. $35 (cloth).
predeterministic view of individual development
If at each point of the germ something else can be
formed than actually is formed, why then does
there happm tn each r R w p s t what happens 2nd
nothing else? (Hans DreLsch, cited on p 64)
This indeed is the question for evolutionary biologists interested in the development
and adaptive roles of complex morphological
features. It may be even more compelling for
those of us uncomfortable with defining evolution in terms solely of changing allelic frequencies and specifically for those trained
primarily in functional morphology or comparative anatomy who always wanted to
know how major morphological innovations
Interested readers ought to look elsewhere for the answers, however. Although
there are some tantalizing explorations in
this book, most of the chapters are devoted
to an incomplete and highly circumscribed
review of 19th and early 20th Century ideas
about the role of developmental processes in
adaptation and speciation. The thrust of
these eleven chapters is to show how mainstream evolrrtionary theorists have overlooked or ignored these ideas and how this
exclusion has weakened the modern synthesis.
Of the three areas of genetic research, (1) developmental genetics (gene action in ontogeny), (2) Mendelian or transmission genetics (parent-offspring
genotypes), and (3) population genetics (the genetic
composition of groups), it is Only the latter two that
have been incorporated in the modern synthesis of
evolutionary thought.
A secondary theme in these chapters is
that the division in the early part of this
century between embryologists and population geneticists has prevented valuable
research into alternative sources for the
origins of new phenotypes (“neopheno0 1992 WILEY-LISS. INC.
that has persisted to the present d a y . . . one that
holds that traits are caused by genes in a straightforward unidirectional manner (p. 8).
In the final three chapters, Gottlieb explores four main lines of evidence that he
wants t o lead us to reevaluate the role of
developmental processes in the appearance
and adaptive roles of novel complex morphological features and their ultimate inclusion
in the genotype. These include 1) experimental evidence that behavioral adaptations during development can affect both the
adult morphological phenotype and, if subjected t o consistent selective pressures, the
genotype; 2 ) experimental evidence that the
early “experience” of the organism can produce behavioral changes and that new behaviors can “create” a new niche requiring
more new adaptations; 3) theoretical and
empirical studies that indicate this “niche
creation” process is related to higher rates of
evolution in larger brained (and behaviorally more plastic) species: and 4)theoretical
and philosophical conclusions that “neophenotypes” created by this process represent
true evolutionary change even without
changes in allelic frequency. Gottlieb seeks
to add behavioral development to the list of
processes that contribute to the ultimate
evolutionary outcome mediated by differential survival and reproduction.
One of the most interesting questions that
Gottlieb addresses is the adaptive role of behavioral plasticity. He points out that data
from both experimental psychology and behavioral ecology demonstrate more behavioral plasticity among mammals and birds
than other vertebrates and more still among
“higher” mammals than others. He argues
that increased behavioral plasticity leads to
more opportunities for and, perhaps, a
greater reliance on behavioral solutions
and fruitful explorations to undertake, but
they are hardly new or revolutionary, as one
might be led to believe from Gottlieb’s introductory remarks. In the field of hominid evolution, for example, the behavioral “niche
creation” process has been an important
component of our attempts to understand
the ecological significance of the early hominid commitment to orthogrady. The new
The neophenogenetic pathway for evolutionary behavior and its associated anatomical
change is thus seen as (1)an alteration of develop- changes make for a new way to interact
ment leading to significant change in behavior, followed by (2) a change in morphology, and eventu- with, exploit, and perceive the environment.
That the genetic changes involved were few
s!Iy, pwsihly (31 R change in genetic composition of
the population (p. 176).
(although very significant) IS weil-established, as is the notion that regulatory or
Finally, Gottlieb argues that the “. . . be- developmental processes played a significant
havioral plasticity that is essential to behav- role in the emergence of early hominids.
From the buildup in the introductory
ioral neophenogenesis is dependent upon
variations in early experience as well as pos- chapters, we keep looking for the radical,
sessing a large brain” (p. 185).Among these revolutionary idea about the role(s) that sobehavioral adaptations, Gottlieb predicts a matic and behavioral development might
play in the origin of novel phenotypes on
central role for exploratory behaviors.
which selection can act. In fact, Gottlieb deIt has been our contention that exploratory behav- scribes a long scientific tradition in this field
ior-when a species is sufficiently plastic to initiate
and an extremely active contemporary proit-places the individual in a different niche facing
gram of research. The reader ivould be surdifferent selective (adaptive) demands and thereby
brings out latent morphological changes that then prised, shocked, and amazed at the results
allow a genetically-based evolutionary change to of these experiments and their implications
follow in its wake. . . ; [and] . . . given the relation- for our understanding of evolutionary proship between large brains and behavioral plasticity,
cesses, only if s h e had never looked more
behavioral neophenogenesis predicts that species
with large brains should show evidence of a faster deeply into evolutionary theory than the
summaries found in introductory biology
evolutionary pace than species with smaller brains
(pp. 191-2).
textbooks; or had never thought seriously
about current experimental and theoretical
To support this point, Gottlieb reviews research into the causes, the processes, and
both experimental and empirical studies of the consequences of morphologcal and getaxon-specific differences in exploratory be- netic change.
havior, rates of evolutionary change, and
brain-to-body weight ratios. In this view, we
Division of Behavioral Biology
ought to see more evidence of behavior as
New England Regional Primate
“supragenetic” evolutionary mechanism in
Research Center
larger brained “higher)) mammals and be
Southborough, Massachusetts 01772-9102
able to produce such changes experimentally or to observe them empirically.
These ideas and the scientific possibilities
that they suggest are exciting, interesting,
when faced with adaptive challenges. The
more that a species relies on behavioral adaptation, the more that these behaviors can
provoke physiological and, ultimately, morphological changes subject t o selection. According to this view, evolution has already
occurred a t this stage with or without
changes in gene frequencies.
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development, cloth, 1992, evolution, university, gottlieb, isbn, 506893, new, york, behavior, 231, novem, pres, gilbert, oxford, individual
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