American Scientist

The Evolving Female: A Life-History Perspective. Mary Ellen Morbeck, Alison Galloway and Adrienne L. Zihlman, eds. 332 pp. Princeton University Press, 1997. $27.95 paper.

Life history is a field in search of a definition. I offer this as a supplement for readers of The Evolving Female: Life history is the study of life plans of organisms; for a mammal, it is the strategy of when to be born, when to be weaned, when to stop growing, when to reproduce and when to die. Females, as an evolutionary biologist would say, have different options (and constraints) for life plans than do males.

The Evolving Female is a collection of essays on life history from the perspective of anthropology and evolutionary biology. The book had a singular beginning; it is the somewhat delayed product of a controversial 1990 conference to which only female scientists were invited. Whatever one's view of the propriety of a woman-only scientific conference, the restriction necessarily shifted the thrust of the conference from science to women in science. All in all, the book redeems the conference, shifting the focus back again toward science.

The first half of the book provides a natural history approach to the lives of primates and some other social mammals. The book gains breadth by including work on sea mammals by Kathryn Ono, who studied sea lions, and Joan Reiteron, who observed elephant seals. These two pinnipeds evolved surprising differences in the length of mother-offspring attachment. The former nurse for a year or more, the latter for only one month. How such divergent strategies might come about when overall life ways seem so similar is a telling problem in life history.

The rest of the book becomes more physiological, taking up the issues of human sex differences, postmenopausal osteoporosis, fat and fatness, sex roles, child care and work energetics and ovulation, pregnancy and lactation. Although the book is not technical, evolutionary theory is prominent in several chapters. In particular, Alison Jolly takes up the fundamental question of the origin and function of sexual reproduction.

Although the volume contains very few figures or tables, the essays are well referenced, and the conjoined bibliography at the end of the book is a valuable guide to the literature. Snapshot case histories that begin a number of chapters add interest and illustrate general points.

The Evolving Female does have some deficiencies, however, including the lack of a firm definition of life history and of a succinct guide to its chief theories. (In fact a list of pertinent theories or questions would have been a great addition to the book.) Because of this omission, many readers may never quite grasp what is the body of "life-history theory" to which the editors and contributors refer. Furthermore, tenets are occasionally misstated: "Life-history theory predicts that ... animals should begin breeding as early as possible." Of all the authors, only one, Caroline Pond, takes a data-based comparative approach to a problem, a basic tool in life-history studies. Finally, no one will miss the repetitious statement of the book's theme. Eventually the phrase "whole organisms, whole lives" becomes, for me, the rhetorical equivalent of "building a bridge to the 21st century."

But at its best, the book allows very talented mature scientists the chance to write an essay about female lives. Interestingly, many comment on their own. Most importantly, The Evolving Female enlarges the body of material that belongs in a standard anthropology curriculum—a curriculum that should include comparisons of male and female life strategies and more information about female biology. This group of essays on the lives of females, as both subjects and scientists, has much to offer.—B. Holly Smith, Museum of Anthropology, University of Michigan