A team of scientists has, for the first time in history, created embryos that are part human and part monkey.
The purpose of the embryos is to pave the way for finding new approaches to produce organs for people who need transplants in the absence of donors.
"This is one of the major problems in medicine, organ transplantation," professor Juan Carlos Izpisua Belmonte of the Salk Institute for Biological Sciences said. "The demand for that is much higher than the supply."
Belief on the ethical nature of the research was split. Case Western Reserve and Harvard University bioethicist Insoo Hyun saw no issues, saying the research is "aimed at lofty humanitarian goals."
Others, however, have sounded the alarm.
"My first question is: Why?" Kirstin Matthews, a fellow for science and technology at Rice University's Baker Institute, said in response to the study. "I think the public is going to be concerned, and I am as well, that we're just kind of pushing forward with science without having a proper conversation about what we should or should not do."