Gregor Mendel could not have foreseen it. James Watson and Francis Crick, who discovered DNA, could not have imagined it. Yet the Orthodox Jewish communities of New York and Israel are applying modern genetic biology to their major life choices.

An organization called Dor Yeshorim, Hebrew for "generation of the righteous," has become an integral part of the community. Dor Yeshorim runs DNA tests on single men and women, and keeps a database of their potential children's susceptibility to certain genetic diseases.

As the literal translation implies, Dor Yeshorim's goal is to ensure that the children born of Orthodox parents are safe from certain genetic diseases whose occurrence is disproportionately higher within that close-knit community. Launched ten years ago by Rabbi Josef Ekstein to test for Tay-Sachs Disease, Dor Yeshorim has expanded its scope to include three other genetic diseases. More than 8,000 people entered the program last year alone.

Dor Yeshorim runs five test centers in the New York area. Each participant receives a six-digit identification number and gives a blood sample; test workers analyze his or her DNA to determine whether it contains certain disease-carrying genes. Before two members of the community begin dating or decide to get married, they can call a hot line which tells them whether or not they risk passing any of the diseases to their children.

While Dor Yeshorim has generally been well received within the Orthodox community, its outside reception has been mixed. Some hail the program as an effective attempt to reduce suffering and to prevent the perpetuation of these painful, often fatal, diseases. Others criticize Dor Yeshorim as a Promethean scenario; modern science has taken another step in abrogating the ancient role of God. In either case, Dor Yeshorim does raise several serious questions with implications far beyond the Orthodox Jewish community.

In New York and Israel, Orthodox Jewish communities tend to be close-knit; much of their lives revolve around religion. Historically, Orthodox Jews arranged their children's marriages. While this is no longer the case, the Orthodox communities still view marriage as an occasion that involves the families as much as the individuals.

Dor Yeshorim is not the Frankenstein its critics fear. Diseases like Tay-Sachs are a serious problem within the Orthodox community; four of Rabbi Ekstein's 10 children died from it. That medical technology can prevent this should be seen as a blessing. Dor Yeshorim sidesteps the question of abortion by preventing the conception of babies doomed to suffer.

But situations are never static, as Dor Yeshorim's history shows. The program continues to expand its scope. As Samuel Lefkowitz, a consultant with the project, asserts in The New York Times, the organization aims to someday test for "anything possible."

Most people are somewhat comfortable with the idea of testing for Tay-Sachs, a fatal, degenerative neurological condition that strikes young children. However, many question the utility of DNA screening for other conditions like Gaucher's disease. The symptoms of this painful degenerative disease almost never appear before a person's mid-40s, and Gaucher's is treatable. Should the distant prospects of non-fatal disease prevent a marriage between two people who love each other? Inevitably, the more diseases added to the list, the more marriages prevented.

Then there is the question of testing itself. Science is not always completely precise. The accuracy of any data is susceptible to a host of laboratory and human errors. Also, scientists still don't know exactly how many genetic diseases operate. These flaws are not reason to stop the Dor Yeshorim program altogether, but couples may want to reconsider shaping their future around a single test.

The most extreme objections to Dor Yeshorim focus on the perils of modern science. Dr. Francis S. Collins of the National Institutes of Health summarized Dor Yeshorim in the Times as "a miniature but significant version of Big Brother," referring to George Orwell's dis-utopian novel 1984.

Imagine if a nationwide program like Dor Yeshorim recorded the genes of every citizen. (Even now, the federal government is attempting to map out the entire human genome.) Would you be comfortable knowing that all your genes are on record somewhere, from your predisposition for baldness to your likeliness to commit violent crimes (scientists have discovered a "crime gene" for males)? Already we are less disturbed than we should be that our privacy, from what we buy to whom we call, is recorded and often sold; in this era, knowledge is money.

Still, some of the more widespread objections to Dor Yeshorim are almost irrational. Obviously, we aren't disturbed by the concept of trying to ensure that a child is the healthiest and the "best" he could possibly be. Increasingly, women are watching what goes into their bodies during pregnancy, refraining from tobacco, alcohol, and even caffeine. No one raises an eyebrow when parents send their children to school early, infusing them with "Hooked on Phonics" and "Reading Rainbow," in an effort to unleash their maximum potential.

Dor Yeshorim disturbs us because it attempts to assure a healthy child even before conception--in fact, before marriage itself. Maybe we're wary of this notion because in the back of our minds, it seems a lot like tampering with Fate.

In today's culture, we view the love that leads to marriage as the highest manifestation of the providence Dor Yeshorim attempts to circumvent. But as the ancient Greeks learned, Fate cannot be avoided; therefore, any attempt to do so seems deceitful.

Every marriage is ultimately the decision of two individuals. But if community pressure is strong enough, people may forsake their desires in order to conform. In the end, balance is the key. What are the chances that a baby will be born with a genetic disease? How serious is the disease? How strong is the love between the potential parents? Are they willing to gamble their future on a scientific roulette wheel?

These are questions that no one but the couple involved can answer. Dor Yeshorim poses no threat as long as these two can make their choice without fearing ostracism from the community.

When the rabbi, or any other official, asks for opposition to the eternal union of two people, a six-digit ID number should not answer the call.