In today's (Thursday's) daily text, the WT comment reads:"-- perfect--first humans, our ancestors-- and informed them that disobeying that law would bring a death sentence--"
The carrying out of that verdict did not require a genetic change, as implied the the "cookie mold " analogy of WT reasoning, but
Genisis makes it simple:
Leave humans as they are, perfect, but
death by withholding of the vital diet ingredient: fruit from the tree of life.
Death by a kind of slow STARVING like "sterben"