This article originally appeared on Beliefnet in December 2001.

A biotech company in Massachusetts has made cellular copies of the human embryo; dozens of laboratories around the world are cloning cattle and sheep; the Bush Administration is offering limited federal support to researchers working on embryonic "stem cells;" and the United States Congress just failed to enact a mildly-worded temporary ban on human reproductive cloning. You're not alone if you think biotechnology is hurtling down the road at 100 miles per hour and the highway patrol doesn't seem to want to pull anyone over.

Two closely-related but distinct issues are at stake: genetic engineering and cloning. Should you be afraid that genetic engineering is about to produce something horrifying? Maybe not. Should you be afraid that human cloning is uncomfortably close? Maybe so.

Rapid as the pace of biotech is, scientists still know just shy of nothing about how to manipulate human DNA. Consider that the gene that causes cystic fibrosis was identified nearly a quarter-century ago, and as genes go it is a relatively basic structure. Twenty five years later -- after many, many millions of dollars have been spent on an intensely studied subject where every researcher is keenly aware that personal fame and a Noble Prize will come to the person who defeats the CF gene - there has been little progress. No one knows how to stop the cystic fibrosis gene from "expressing" itself, or any practical way to get it out of human chromosomes. And the CF gene is a single, simple challenge compared to such prospects as making people taller, stronger, smarter or blonder.

It's well to bear this in mind when you hear proclamations that scientists are on the verge of bizarre, Brave New World alterations of Homo sapiens. Probably the ability to genetically engineer human beings will be attained at some point, and an awful lot of careful thinking will be required before we decide whether genetic alterations should be allowed. But there's no reason to oppose them in principle.

First, genetic alterations have been happening to humanity for millions of years: regardless of whether God or spontaneous forces drive the process, Homo sapiens sure is different from Homo hablis, the first known species of man. Next, the initial stages of human genetic engineering will focus on the prevention of inherited disease - if only because disease cures bring strong financial incentives. Purists who maintain that humanity should not tamper with DNA at all will be hard-pressed to argue against the eradication of cystic fibrosis, Down syndrome, sickle-cell anemia and other conditions. Assuming genetic engineering based on "editing" (simply removing an unwanted gene such as the one that causes CF) becomes possible, the next phase would also likely concentrate on health, by enhancing: ramping up the genes that control immune response or healing, for example. It's going to be pretty hard to argue against that, too.

Then might come the types of genetic engineering that people fear: not just making people more healthy but altering what they are, even if with good intent--by making people smarter or stronger, for instance.

No one today has the slightest idea how this might be accomplished, because scientists don't yet know how our genes make us smart or strong in the first place. This is why Craig Venter, head of the Celera Genomics, the private company "mapping" the human genome, has called the idea of making super-people (or human drones, or anything else) "science fiction." No researcher knows where on the 23 human chromosomes is the information that forms our brains or muscles, to say nothing of which gene makes people blond rather than brunette.

Complex traits such as intelligence are likely to turn out to result from complicated interplays of multiple regions of DNA: odds are, there is no "IQ gene." Consider that studies now show there are somewhere between 30,000 and 75,000 total human genes. But an adult person has one trillion nerve cells connected by 1,000 trillion synapses. If DNA alone is dictating how our central nervous system works, these figures mean each human gene is controlling on average three billion synapses - along with everything else each gene must shape.

Numbers like that just don't sound right. Very complicated interactions among genes, growth, and learning are likely to form intellect, and it may take a long time to figure out how to enhance this process, assuming it can be done at all. Same with strength or beauty or other areas where people might long to enhance inheritance. In turn, the difficulty of figuring out how to engineering for traits that we know exist, such as brainpower, suggests even more problems engineering for "novel" traits--ones which currently don't exist.. Some worry, for example, that genetic engineering could be employed to create mind control. But mind control does not exist in nature; scientists would have to invent an entirely new property without any genetic guide. This seems far-fetched.