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Book Reviews: Unmasking Misconceptions

Book Reviews: Unmasking Misconceptions

Cracking the Genome: Inside the Race to Unlock Human DNA
By Kevin Davies. New York. The Free Press, 2001. 310 pages. Hardcover.

The Triple Helix: Gene, Organism, and Environment
By Richard Lewontin. Cambridge, MA. Harvard University Press, 2001. 144 pages. Paperback.

It Ain’t Necessarily So: The Dream of the Human Genome and Other Illusions
By Richard Lewontin. New York. New York Review Books, 2001. 368 pages. Paperback.

Exploding the Gene Myth: How Genetic Information Is Produced and Manipulated by Scientists, Physicians, Employers, Insurance Companies, Educators and Law Enforcers
By Ruth Hubbard and Elijah Wald. Boston. Beacon Press, 1999. 225 pages. Paperback.

The Human Genome Project (HGP) and affiliated technologies, such as cloning and stem cell research, elicit both confusion and concern. Advances in biotechnology may promise cures for many horrible diseases, but they also seemingly place scientists in the position to play God. As society stands at the threshold of this “brave new world,” Christian apologists can help chart a path through the encroaching bioethical maze. Four recently published books equip the Christian community to influence the future direction and application of biomedical research.

Cracking the Genome tells the story of the HGP and the people who shaped it. This book—written by geneticist Kevin Davies, the founding editor of Nature Genetics and the executive editor of Current Biology—captures the HGP’s excitement and intrigue. In the midst of conveying the story, Davies masterfully presents an accessible description of the molecular biology behind the HGP and its potential applications.

Cracking the Genome serves as an excellent resource for anyone looking to better understand the basic science related to the HGP. It also offers great behind-the-scenes insight into the politics accompanying advances made by HGP researchers. This book falls short, however,  in providing a balanced and scientifically realistic treatment of the project’s potential applications.

Davies, like many in the HGP community, portrays HGP research as yielding biomedical technology that will allow for such applications as the diagnosis of diseases before symptoms occur, replacement of defective genes, embryonic screening for “desirable” traits, genetic engineering of children for “perfection,” and even evolution directed by human effort. And yet he fails to adequately convey that most, if not all, of the potential applications touted—particularly those most bioethically disconcerting—lack credible scientific basis and face potentially insurmountable technical obstacles.

While Davies brushes off the significant challenge facing those researchers who seek to derive utility from the HGP data, distinguished Harvard biologist Richard Lewontin does not. Lewontin critically evaluates the visionary applications of the HGP and other biotechnology in The Triple Helix and It Ain’t Necessarily So. In both books, Lewontin presents a sound scientific case for what he sees as the imminent failure of the HGP.

The Triple Helix, adapted from three lectures presented by Lewontin at the Lezioni Italiani in Milan, deals with common misperceptions about genes, the environment, and organisms. Nonscientists and biologists alike appear to hold these misconceptions. The chief misperception Lewontin takes on—the one most relevant to the HGP—is genetic reductionism. This view maintains that genes determine the organism. Lewontin convincingly demonstrates that organisms arise from something more than genes alone. Rather, he argues, an organism emerges from a complex nexus of interactions among genes, the environment, and random chemical events.

Both the environment and the complexity of genetic and environmental interactions profoundly affect every potential application for the HGP’s data. An individual possessing a defective gene or the genetic fingerprint correlated with a particular disease, such as cancer, offers a case in point. Due to the environment’s role, this person’s genetic makeup may—or may not—predict that he will suffer from that disease in the future. Even Davies in Cracking the Genome notes the results of twin studies indicating that environmental factors play a more important role in cancer onset than genetic susceptibility (p. 230). According to these studies, only about 10% of identical twins, genetically indistinguishable from each other, share the disease. Given that this is the norm, predicting the onset and course of diseases from genetic data seems hopeless.

Lewontin continues his critique of the HGP in It Ain’t Necessarily So. This book contains a collection of essays Lewontin wrote for The New York Review of Books. The essays appear as originally published, with epilogues to update each review.

In “The Dream of the Genome” essay, Lewontin discusses the brute scientific reality standing in the way of HGP applications. As in The Triple Helix, he focuses on the gene’s misperceived predictive power. In addition to highlighting problems associated with genetic reductionism, Lewontin critiques the misplaced hopes attached to the HGP by pointing out that the most widespread diseases in the western world do not follow a one gene, one disease model. While scientists know of many diseases caused by mutations to a single gene, the etiology (cause) of diseases, such as cancer, hypertension, heart disease, stroke, and diabetes, involves an ensemble of genes and multiple environmental and lifestyle factors. Researchers have little hope of ever deciphering the web of interactions leading to these diseases, let alone of achieving the capability to accurately predict an individual’s likelihood of developing polygenic, multifactorial diseases.

Lewontin also dashes the hopes of HGP futurists who claim that the ability to screen or engineer embryos for desired traits looms just around the corner. He rightly points out that no single gene determines any biological trait. Rather, multiple genes interact to produce each trait. Conversely, each gene impacts numerous traits. Again, researchers have little prospect of sorting out the intricate genetic interactions that contribute to an individual’s characteristics. In the absence of this understanding, embryonic screening and genetic engineering hold little prospect for utility.

Researchers face problems even in the simplest scenario, where a single defective gene produces a particular disease. Biomedical scientists hope that once a defective gene has been identified it can be replaced by a healthy gene using so-called gene replacement therapy. Lewontin shows that this simple idea, to date, is not viable and that significant technological hurdles stand in the way of gene replacement therapy. No technology exists to introduce a healthy gene into the human genome. Consider cystic fibrosis for example. The defective gene causing cystic fibrosis has been known for 15 years. Still, biomedical practitioners lack the ability to correct this genetic defect.

The absence of viable gene replacement therapy means not only that diseased genes can’t be replaced, but also that undesirable genes can’t be replaced in human embryos. Genetic engineering in humans lacks technical feasibility.

Lewontin’s exposés in The Triple Helix and It Ain’t Necessarily So stem from his concern that genetic reductionism sidetracks biology from making critical conceptual advances. In The Triple Helix, he explores why scientists embrace genetic reductionism—even in the face of widely acknowledged scientific facts to the contrary. Lewontin sees the roots of genetic reductionism in the philosophical and methodological approach of current biology.

In Exploding the Gene Myth, Harvard biologist Ruth Hubbard and her son, writer and artist Elijah Wald, take on the myth of genetic reductionism from a scientific standpoint, much as Lewontin does. Hubbard and Wald, however, attribute the prevalence of genetic reductionism in the scientific community not just to philosophical and methodological considerations, but also to cultural, social, political, and economic concerns. They point out, for example, that many of the scientists involved in propagating the gene myth receive funding from, or hold stock in, biotechnology companies—companies that would benefit economically from widespread genetic screening. In fact, Nobel Laureate James Watson was forced to resign as head of the Human Genome Project because of his biotechnology holdings and his refusal to pursue gene patents on behalf of the National Institutes of Health. With gene sequences as part of the public domain, biotechnology companies and their shareholders benefit directly from taxpayer-supported research.

Hubbard and Wald are less concerned with the impact of genetic determinism on the direction of future scientific research, than on the impact an over-emphasis on genetics will have on public health and society. Hubbard and Wald consider genetic screening and the prospects of genetic engineering as the new “eugenics” (attempts to make a perfect species). Moreover, they express well-founded concern about genetic discrimination by employers and health insurers, as well as abuse of genetic data by the legal system. Hubbard and Wald’s reservations carry even more poignancy given the lack of scientific foundation for genetic screening.

The Triple Helix, It Ain’t Necessarily So, and Exploding the Gene Myth all offer an accessible, refreshing, and scientifically credible counter to the hyperbole surrounding the Human Genome Project. These books highlight the importance of understanding the science related to the HGP (and other controversial areas of biotechnology) and of recognizing the distortions associated with its applications. In light of this information, many of the bioethical concerns arising from the project evaporate. Making these facts known prepares everyone to better direct the development of appropriate and attainable applications of HGP data.