It just suddenly occured to me today...
You know the jws always say about Adams sin being passed on to his descendants that its like you have a bread pan with a dent in it and that every loaf of bread will then have a dent? Well that's fine for bread, cos your using the same pan. But that's not how genetics work?
The illustration would work if Adam kept on fathering kids but he didn't. If a family has a disease that is passed along, with more and more genes and DNA eventually the disease will be bred out.
The illustration might also work if you said that you made a mould of each loaf of bread, then made that mould into a new bread tin, and then kept on doing that. .. although wouldn't that eventually result in the dent disappearing?
Anyway didn't Jesus also say not to punish children for the sins of their parents? Pretty insane since that's exactly what his dad did!