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Stanford scientists discuss the nature of human nature at Bay Area science festival

Despite the hoopla surrounding the Human Genome Project, genes do not control our destinies, say Stanford biologists Marcus Feldman and Paul Ehrlich.

The two researchers spoke Sunday at the fourth annual Wonderfest, a two-day Bay Area festival where scientists discuss controversial issues in front of a public audience. The festival is dedicated to the memory of astronomer Carl Sagan.

This year's festival included debates on the definition of life, the relationship between mind and body, the threat of global warming and the existence of life on other planets. The 12 participating scientists hailed from Stanford, the University of California-Berkeley, UCLA, the SETI Institute and the NASA-Ames Research Center.

Feldman and Ehrlich, who have both written extensively about genetics, discussed human nature whether it exists, whether it can be changed and what genes have to do with it.

Ehrlich, the Bing Professor of Population Studies, began the discussion with the idea that there is not one human nature, but rather multiple human natures an idea he has discussed at length in his recent book Human Natures: Genes, Cultures, and the Human Prospect (Island Press, 2000).

Feldman, the Burnet C. and Mildred Finley Wohlford Professor in the School of Humanities and Sciences, also rejected the idea that genes determine human nature. He argued that the interaction between genes and the environment, both physical and cultural, is far more important than genes alone.

Unfortunately, many people in the United States have been misled about the importance of genes, partly because of active campaigning by people who have vested interests in the field, Feldman said.

The exaggerated claims made by some geneticists are similar to the claims made by astrologers both try to predict the future on the basis of insufficient evidence. "There's no blueprint in our genes, and there's no blueprint in the stars," said Feldman.

Nonetheless, the news media constantly are reporting studies that say there is a strong genetic basis for traits such as intelligence, personality, voting behavior and even the kinds of clothes we choose to wear. But those traits, said Feldman, are actually the result of a development process that is just as strongly influenced by the environment as it is by genes. The interactions between genes and the environment are so fundamental that even a comprehensive understanding of the genes involved in intelligence something far beyond today' s scientific knowledge would be useless without an equally thorough understanding of the environment in which those genes operated.

The growth of plants, for instance, is relatively simple compared to human behavior, but even it can be strongly influenced by changes in such environmental conditions as light, heat and soil nutrients. Those influences can lead to dramatic differences among plants that have identical genes.

Researchers long have known about the importance of gene-environment interactions. But the influence of environment has tended to be overshadowed by recent strides in molecular biology, such as mapping the human genome, said Feldman.

Ehrlich and Feldman argued that understanding genetics is important for the general public, not just for academics. Advances in genetic testing for health problems have created a very real threat of a "new eugenics" one based not on reproductive control, but on the availability of health insurance. Although discrimination on the basis of genes has not yet become a reality, insurance companies increasingly will be tempted to use genetic tests in the same way they now use demographic information to adjust premiums, Feldman said.

Ehrlich also warned of attempts to use genetics to support racism. Researchers have just as much justification for trying to link IQ to skin color, he said, as they do to link IQ to the ability to roll one's tongue. Tongue-rolling and skin color are equally superficial; the choice to focus on one instead of the other is motivated not by science but by ideology. "Why the hell are they doing it?" asked Ehrlich. "It's very hard to come up with any answer except straightforward racism."

During the last hour of the discussion, when audience members were invited to ask questions of the researchers, Feldman and Ehrlich suggested that what scientists discover about genes cannot dictate what society as a whole should do to improve people's lives. No genetic test or any other kind of test, for that matter can determine what we can or should do to improve the life of a person with a particular disorder. "Even if we knew a gene that was causing [a trait], that doesn't say anything about how we should intervene in improving [the trait] or changing it," said Feldman.

The important thing is to make sure that everyone has a say in the kinds of changes to human nature we try to make and the methods we use to make them, said Ehrlich. "We have to do it openly, or democratically, or else we're headed down the wrong path."


This article was written by science writing intern Etienne Benson.


By Etienne Benson

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