Uterine replicators are happening. (note for Bujold fans!)

"Dr. Hanna said he and his colleagues had taken fertilized eggs from the oviducts of female mice just after fertilization — at Day 0 of development — and had grown them in the artificial uterus for 11 days." https://www.nytimes.com/2021/03/17/health/mice-artificial-uterus.html https://www.nature.com/articles/s41586-021-03416-3