Good ol' genetics teaches us that virtually every single complex biological organism on the planet ages and dies by the exact same process as human beings (telomerase reduction in cell subdivision), which is, needless to say, really hard to reconcile with the WTS's "dented mold" hypothesis of "human imperfection"...
...after all, if we grow old and die because we're "imperfect", and all the animals grow old and die by the same physical process, does that mean animals are punished with "imperfection"? And if so, how could they have "sinned" in order to have received said punishment?
Also, if Adam and Eve were created "perfect" (i.e. immortal), doesn't that mean that animals are "imperfect", and if so, why would a "perfect" God create "imperfect" things?
I actually asked these to another JW I knew a long time ago, and he basically tried to explain it by suggesting that "perfection" was actually subjective.
I had to make an effort to not roll my eyes, and never discussed WT theology with him again.