(MONEY Magazine) – Twenty years ago, Jeremy Rifkin co-wrote Who Should Play God, which predicted advances in biotechnology like cloning and warned that they posed ethical dilemmas we ignored at our peril. In his new work, The Biotech Century, Rifkin says that we're still ignoring the moral and social issues raised by manipulating genes in pursuit of better "products"--be they plants, animals or our children. MONEY spoke with Rifkin in July.

Q: What are the broad risks we'll face in the Biotech Century?

A: This is an era as daunting and challenging as the advent of the Industrial Age, and it's going to come with problems that are probably far more chilling: environmental, social, ethical and cultural problems. Why? Because this revolution allows us to begin to reconfigure the blueprints of evolution for market-oriented purposes.

Q: Companies are now patenting genes. Why does that give you pause?

A: Thousands of genes and chromosomes, cell lines, tissues, organs and even whole organisms, whole genomes, are getting patents. Myriad Genetics now owns a breast-cancer gene. Myriad isolated a gene that causes breast cancer. Now there's a test for that gene. And if you go for that test, part of what you're paying for is access to screen for that gene. This is a major theological issue--is the gene pool God's creation or is it a corporate invention? It can't be both.

Q: You've written a lot about the dangers in commercial eugenics. What's wrong with giving people a choice in what physical and other characteristics are passed to their children?

A: We normally think of Nazi Germany when we think of eugenics. But the new eugenics is banal. We're all being asked as consumers, "Don't you want healthy babies?" But who determines what that perfect baby should look like? And how tolerant are we likely to be of babies who aren't programmed, who may have physical and mental disabilities? Will we be empathetic or will we see them as errors in the code, or miswired?

Q: So what do we do in the face of the possibilities of the Biotech Century?

A: The science here is not in question. The science is valuable. The issue is what kind of technologies will we use in the marketplace and society to apply our knowledge. You could use this science to change the genes in the sperm and egg so that you eliminate diseases before you get them. That's very problematic and raises a lot of eugenics questions. Or you could use the same science to understand the relationship between genetic predispositions and environmental triggers for diseases, so that you keep people healthy.

The rule of thumb ought to be the Hippocratic oath: First, do no harm. Second, choose the path that's least likely to cause radical discontinuities now and for future generations and that integrates our relationships with the biological system.

The most chilling prospect is that the marketplace may be the ultimate arbiter of the destiny of the human race in terms of its biological design. I'm a believer in the marketplace, but it's not well suited for making decisions that affect future generations.