Chimera Embryos

Scientists have now successfully grown human cells in a monkey embryo. The idea is that maybe one day we can grow human organs in monkeys or pigs that could save the lives of people languishing on organ transplant lists. That’s great, but does it mean creating monkeys that are part-human? There are so many ethical questions surrounding this research that the scientific study on the human-monkey experiment was published with a companion essay co-authored by leading bioethicist Hank Greely of Stanford University.