This article follows last week’s CalCatholic story: New form of stem-cell engineering raises ethical questions.

For nearly 40 years scientists have observed their self-imposed ban on doing research on human embryos in the lab beyond the first two weeks after fertilization. A group of Harvard University scientists has published a paper arguing that it is time to reconsider the 14-day rule because of advances in synthetic biology.

“We can get so distracted by the apparent issues with embryos that we might miss issues more likely to have a huge impact on society and commercial and governmental policies,” says George Church, the Harvard Medical School synthetic biologist and geneticist who is the senior author of the article, published Tuesday in eLife.

Now is the time to begin a public discussion on experiments such as these, Church argues, before it is scientifically viable and poses an ethical challenge to the 14-day rule.

Not surprisingly, these ideas have triggered some opposition among bioethicists. The Rev. Tadeusz Pacholczyk, a neuroscientist and director of education at the National Catholic Bioethics Center in Philadelphia, wrote via e-mail that any research on embryos or something like them is unethical, regardless of the 14-day rule. “In cases of doubt, where one has a suspicion but not certainty that one might be engendering an embryonic human, such experiments should not be continued,” he wrote.

Others, however, praised Church for starting the discussion before the science catches up with it. “I think it’s a service to write a paper like this,” says Josephine Johnston, director of research at the Hastings Center, a nonpartisan bioethics research institution. “Not every scientist wants to draw attention to why their research may cross some boundaries.”

The work of synthetic biologists poses particular ethical challenges in part because their models are getting more and more accurate, says Insoo Hyun, a bioethicist at the Case Western Reserve University School of Medicine. Having a discussion ahead of time should help prevent decision-making based on gut instinct of what seems offensive versus well-reasoned arguments, Hyun notes.

Church says he does not know where new boundaries should be drawn to contain future synthetic biology research—but instead of a stop sign at the end of the research road, like the 14-day rule, his team imagines a perimeter fence to keep scientists from straying too far from an ethical path.

George Annas, director of Boston University School of Public Health’s Center for Health Law, Ethics and Human Rights, says he is glad Church and colleagues are flagging this research, which might otherwise be overlooked. He also agrees that recent advances in stem cell science, genetics and synthetic biology suggest it is time to question whether the 14-day rule has outlived its usefulness: “I think it’s a fair question,” he says.

Full story at Scientific American.