The little clump of cells looked almost like a human embryo. Created from stem cells, without eggs, sperm, or a womb, the embryo model had a yolk sac and a proto-placenta, resembling a state that real human embryos reach after approximately 14 days of development. It even secreted hormones that turned a drugstore pregnancy test positive.

To Jacob Hanna’s expert eye, the model wasn’t perfect—more like a rough sketch. It had no chance of developing into an actual baby. But in 2022, when two students burst into his office and dragged him to a microscope to show him the cluster of cells, he knew his team had unlocked a door to understanding a crucial stage of human development. Hanna, a professor at the Weizmann Institute of Science in Israel, also knew that the model would raise some profound ethical questions.

https://www.theatlantic.com/health/archive/2024/10/human-embryo-model-ethics/680189/?utm_source=msn