Mother Nature: A History of Mothers, Infants, and Natural Selection

Along the Evolutionary Biological Trail A review and commentary on: Mother Nature: A History of Mothers, Infants, and Natural Selection by Sarah Blaffer Hrdy (1999) Pantheon Books. 723 pages. ISBN: 0-67944-265-0. Mother Nature: A History of Mothers, Infants, and Natural Selection by Professor Sarah Blaffer Hrdy, an emeritus professor of anthropology at the University of California at Davis, is a monumental multidisciplinary treatise that summarizes her life's work and which, I believe, is destined to become a classic in the field and a core text for many university courses and seminars on Mother Nature. How does one provide a fair "review", in about 2,500 words, of a monumental text with 55 pages of Notes and 44 pages of bibliography? It is a mission impossible. So the following observation, by necessity, has to be selective and limited. Because of my own research on some of the issues Hrdy investigates I have also added some analysis, commentary and suggestions. Hrdy's treatise is really two books in one. The first part, a sweeping scientific overview of evolutionary biology and its implications for human maternal behavior, should have been left to the special interests of the scientific community interested in documenting the early "evolutionary trail", which has little predictive validity for human primate maternal behavior. As interesting as the maternal behavior of insects, birds and fishes may be, they have no predictive validity for human maternal behavior. Such material, invaluable in its own right, detracts from the ultimate mission and audience intended by this text-contemporary mothers who also have a "mission impossible" i.e. to do what is not only best, but necessary, for the healthy development of her infant/child. That portion of the "evolutionary trail" most relevant to understanding the complexity of a homo sapiens mother is, of course, the primate order, not even the mammalian class. Hrdy has shown that the body of evidence about the primates is so extensive and characterized by such great variability, that predictive validity from infrahuman primate specific behaviors to human primate specific behaviors is fraught with great difficulty (Chapter 4: Unimaginable Variation and Chapter 5: The Variable Environments of Evolutionary Relevance). A problem I encountered is the ease with which Hrdy can move from insects, birds and fish to primates in her comparative analyses throughout the text. Hrdy has, however, identified some infrahuman primate maternal behaviors that have high predictive relevance and validity for homo sapiens maternal behavior, but not many. One of the great challenges is sorting out the proportional relevance of genetic biology from non-genetic biology from culture in accounting for the high variability of maternal behaviors along the evolutionary trail. Another challenge is trying to determine the ultimate importance of Darwinian evolutionary biology for understanding the complexity of human maternal primate behavior.1 Hrdy quotes the sociobiologist Mary Jane West-Eberhard who maintains that, "Nothing is genetically determined in the sense of determined by genes alone. No gene is expressed except under particular circumstances. It's a kind of biological illiteracy to talk about a gene for anything other than a particular protein molecule" (p. 57). Hrdy reinforces this point, indicating that, "No gene or set of genes, or even any one mechanism influencing people to favor kin, has been identified. We do not know even a fraction of the ways that kin selection works" (p. 63). These observations are critical in understanding the crucial role that culture or environment plays in the ultimate structure of the complexity of maternal behaviors and the limiting role that Darwinian evolutionary biology must have on human maternal behaviors when compared to the forces of cultural evolution. A comparison with homo sapiens closest living genetic relative-the bonobo chimpanzee is illustrative. …