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)код для вставкиСкачать
AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 89:127-131 (1992) Book Reviews genesis”). It is clear to Gottlieb that the fault for the exclusion of developmental studies INDIVIDUAL DEVELOPMENT AND EVOLUTION: THE from the field of evolutionary biology lies DEVELOPMENT OF NOVEL BEHAVIOR. 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 arise. 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 128 BOOK RLEVIEWS 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 ANDREW J. PETTO 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.