37 (A) Scientists have tried to replace disease-causing genes with healthy ones. (B) In this way, the genome of the recipient is changed, but this change is not passed onto the next generation. (C) Understandably, people have fears about this powerful technology and are worried that we may use it in ways to change our humanity. (D) Many people falsely assume that germline genetic engineering is already performed with regularity, due to news reports of genetic manipulation.