Cloning is back on the front pages, although not for any breakthroughs in science. Steady steps in improving the technology suffice. In the four years since the announcement of the cloning of Dolly the sheep, researchers have succeeded in cloning several mammals: cattle, mice, goats, pigs and monkeys. New companies are being formed to go into the business of cloning pets.

In agriculture, DeForest-based Infigen has produced over 100 cloned cattle, and is beginning the commercial production and sale of cloned bulls and cows.

Infigen's rate of success of getting a live calf by implanting a cloned cattle embryo into a cow is now around 17%, according a story in the Washington Post on March 26. In contrast, Ian Wilmut's group tried 277 embryo transfers before successfully cloning Dolly in 1996. As the success rate and the experience with cattle and other mammals increase, and as time passes, the likelihood that someone will seriously attempt to clone a human also increases.

In fact, the Washington Post story on Infigen appeared just two days before a hearing by the oversight subcommittee of the House Committee on Energy and Commerce on the issue of the announced plans by two groups to develop human cloning.

Most scientists and scientific organizations, such as the American Society for Reproductive Medicine, reject human cloning as unethical because it is too dangerous or as immoral because it is an affront to human dignity.

In any case, scientists still expect cloning will clone only the body and not the personality, not the memory, and not the person. Therefore, it's a plausible new method of reproduction but not a plausible method of resurrection nor of immortality.

We can already know about human clones because identical twins are human clones.

We know that human clones are distinct persons biologically, legally and morally. They are "identical twins" but they have separate identities. We know that their unusual method of coming into the world does not necessarily change their legal or moral status.

We already know that if some legislature wanted to make a law favoring or penalizing identical twins, or any group, all that is required is a proposal supported by a sufficient majority. Likewise, any moralist or ethicist could assign special status, for good or ill, to identical twins. This is true for any targeted group, and history provides plenty of examples of special status awarded or imposed by legislation, regulation or tradition.

In many countries, it is illegal to attempt to clone humans using Dolly Technology. It is illegal in many countries to attempt to insert a nucleus from a single human cell into a human egg cell from which the egg nucleus has been removed.

In the US, no specific statute currently outlaws such attempts. Specific regulations prohibit the spending of federal money on cloning research. Some members of Congress are considering legislation to ban human cloning.

However, the Food and Drug Administration has announced that it requires any researchers proposing to perform such attempts to first request and receive and Investigational New Drug Permit. At the March 28 hearing FDA officials issued a statement that "because of unresolved safety questions on the use of cloning technology to clone a human being, FDA would not permit the use of cloning technology to clone a human being at this time."

The FDA's use of the term "human being" means "human baby" and not human cells or tissues or organs. That's important because depending on the definition, "cloning research" can include research into human stem cells that researchers know how to treat so the cells will grow into different types of cells, tissues, or organs. This research offers the possibilities that one's own cells can become a significant source for healthy cells, tissues or organs to replace, for example, defective blood cells, or a mauled ear, or even a malfunctioning liver, heart or kidney. This type of research has celebrated personalities backing it as a hope for curing diabetes, Parkinson's disease and spinal cord injuries.

So the challenge facing people who wish to craft a ban on research in human cloning is how to make a ban that stops research into cloning for making a baby while allowing cloning research aimed at ends that are more generally, although not universally, accepted.