Genetic memory(?). Dad has tip of finger cut off, son has shorter finger.

Does this diserve a warning? [sic] Which was from same poster. But it’s locked now, so there is need to start a new one, if one is so moved.

Not so; just google epigenetics or dna methylation. What happens to the parents can effect the offspring. Not like in the OP, that’s absurd, but if, for example, the parents experience starvation, this can effect the metabolism of their offspring and continue even further down the line. It is an area of active research. It actually is a form of Lamarkism (forget Lysenko; he was just a political hack, saying what Stalin wanted to hear).