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Fertility is undoubtedly the least often discussed facet of the reproductive process, in large part because scientists haven't had the tools needed to study it until recently, but also because, well, it's just not very sexy. But as Ellison, professor of anthropology and dean of the Graduate School of Arts and Sciences at Harvard, shows in this comprehensive study, fertility plays a far more important role than the sexual act in our development as a species. "It may well be... that it was an adaptation in our reproductive physiology that originally set the stage for our intellectual and cultural development," he asserts. But important aspects of female physiology aren't obvious outcomes of natural selection: the head size required for the relatively large fetal brain played a major role in the high incidence of women's death in childbirth in earlier centuries. The author tells us that scientists have discovered that there seems to be little correlation between sperm counts and male fecundity. One man can have the minimum normal sperm count of 15,000-20,000 per milliliter and another an astonishing 250 million, but both face roughly the same odds of impregnating a fertile egg. Ellison tilts perhaps a little too strongly toward female fertility; males receive only one relatively short chapter. The book is not an easy read and will probably appeal mainly to professionals in medicine and related fields. Still, any reader will be astounded not only by how much has been learned about human fertility but by how much still remains to be explored. (Mar.)
Copyright 2001 Reed Business Information, Inc. --This text refers to an out of print or unavailable edition of this title.
Ellison describes the evolution of human reproduction clearly and concisely, beginning with the forces that shaped the process of conception and^B proceeding to the reproductive process, birth, and the subsequent six months of development. Focusing heavily on the biochemical basis of reproduction, he notes competing theories as to the origins and development of each major reproductive event, evaluating them in the context of current research. Most interesting, however, is the concluding description of how evolutionary forces shaping human reproduction allowed for the development of greater brain size and especially for the development of the neocortex, thereby laying the foundation for early humans' dramatic increase in intelligence. Adapting to a food-availability pattern consisting of alternating abundance and want, hominids developed the ability to store fat in large quantities. Consequently, mothers could store fat in the early stages of pregnancy, becoming abler to meet fetal energy demands, including the very high demands of developing brain tissue, in the later stages of pregnancy. Sure to delight anyone interested in the external forces that helped create humanity. Bonnie Johnston
Copyright © American Library Association. All rights reserved --This text refers to an out of print or unavailable edition of this title.