The pieces are presented in chronological order. A 1981 review of Stephen Jay Gould's The Mismeasure of Man is really a brief essay on intelligence and intelligence testing. An update looks at newer evidence from a 1990 twin study in Minnesota.
"A trait can be 100 percent heritable in the circumstances in which that heritability was measured, yet be easily changed. If that were not true, medical genetics would lose most of its interest. People with two copies of the mutation for Wilson's disease used to die in early adolescence or early adulthood with absolute certainty, because of the lack of a single enzyme. Now they survive by taking a simple pill that makes up for their chemical deficiency. Wilson's disease used to be 100 percent heritable, but is no longer. ... The "heritability" of a trait only measures the proportion of variation among people that is caused by the variation of their genes in the present array of environments and for that specific trait. Thus an estimate of the heritability of a characteristic has no predictive or programmatic value."
Among the less focused reviews, "Darwin's Revolution" looks at a potpourri of eight books published around the Darwin centenary in 1982, spanning everything from creationism to history of science to debates within evolutionary biology to a popular introduction to evolution. "Darwin, Mendel, and the Mind" reviews biographies of Darwin, Mendel, and Lamarck and, for something completely different, Changeux's Neuronal Man. "The Science of Metamorphoses" has two separate parts, one on a biography of Jacques Loeb and the engineering approach to biology and the other on Edelman's Topobiology.
"The Dream of the Human Genome" looks at nine books published around 1990, when the human genome project was just getting under way. In it Lewontin critiques the grandiose claims and hidden assumptions of the project, as well as highlighting the vested interests of the participants ("no prominent molecular biologist of my acquaintance is without a financial stake in the biotechnology business") and the controversies over the use of DNA forensic evidence. A decade later, that all holds up rather well, but an update considers recent developments.
"Women versus the Biologists" looks at a whole collection of books by Ruth Hubbard, encompassing debates over the nature of biological and social differences between the sexes, and over women in science. And in "Sex, Lies, and Social Science" Lewontin critiques a 1994 survey of American sexual practices, focusing on the unreliability of self-reporting. In response to a claim in the resulting exchange that it was inappropriate for a biologist working on "simple" animals to review a book "formulating a social perspective on human sexual conduct in the United States", a rare autobiographical note illustrates how Lewontin's interests extend beyond the population genetics of fruit flies:
"Although a biologist, I have a graduate degree in mathematical statistics and have taught the subject for forty years. About 10 percent of my technical publications, including a textbook of statistics, have been devoted to problems of statistical sampling, estimation, and hypothesis testing. More important, my biological work must be classified as methodological, my chief contribution to the field having been an analysis of the deep epistemological difficulties posed by the data of evolutionary genetics and the introduction of new experimental approaches specifically designed to overcome the ambiguities. Finally, my work on epistemological problems, produced both alone and with philosophers of science, appears in standard philosophical journals."It Ain't Necessarily So itself, though, is free from statistics.
"The Confusion over Cloning" considers a 1997 report from a bioethics advisory commission on cloning, exploring the ways in which the assumptions of genetic determinism lead to confused thinking about the subject — and explaining some of the real safety issues involved. And "Survival of the Nicest", a review of Sober and Wilson's Unto Others, considers the debate over the origins of altruism and the role of group selection.