I suppose that we are messing about with nature all the time when we undertake interventions - transplants and IVF, as you say, also drugs to cure diseases, contraception, blood transfusions, surgery, vaccinations, anaesthesia (and pain relief in childbirth was once thought unnatural - "in pain shalt thou travail and bring forth children" - Queen Victoria decided that she was not amused by suffering in her first seven deliveries and took chloroform during her eighth)
Dental implants - full mouth restoration
June '25 Limerick (July '21 & July'23 continued)

