Researchers have developed a method of harvesting skin cells and transforming them into egg and sperm cells that could them form embryos, but, the New York Times reports, many scientists are unsettled by the prospect. The process, known as in vitro gametogenesis, or I.V.G. for short, could, for instance, enable two men provide all the genetic material for a new embryo. The procedure has already been successfully used on mice, but not yet on humans. However, not all are enamoured of the prospect. “Basic research is paramount, but it’s not clear that we need new methods for creating viable embryos,” said David Lemberg, a bioethicist at National University in California. “Attempting to apply what we’ve learned to create a human zygote is dangerous, because we have no idea what we’re doing, we have no idea what the outcomes are going to be.”